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U.S. Fish & Wildlife Service
Arthur R. Marshall
Loxahatchee National
Wildlife Refuge
Comprehensive
Conservation Plan
USFWS Photo
Arthur R. Marshall Loxahatchee
National Wildlife Refuge
10216 Lee Road
Boynton Beach, Fl 33437
Telephone: 561/732 3684
Fax: 561/369 7190
U.S. Fish & Wildlife Service
1 800/344 WILD
http://www.fws.gov
September 2000
Comprehensive Conservation Plan I
Table of Contents
I. Background __________________________________________________________ 1
Introduction __________________________________________________________ 1
Purpose of and Need for the Plan________________________________________ 1
Planning Process ______________________________________________________ 2
The U.S. Fish and Wildlife Service ______________________________________ 3
The National Wildlife Refuge System ____________________________________ 3
A.R.M. Loxahatchee National Wildlife Refuge ____________________________ 4
History ___________________________________________________________ 4
Purpose ___________________________________________________________ 7
Ecosystem and North American Context ______________________________ 7
Role of Refuge in South Florida Ecosystem Plan_____________________ 7
Role of Refuge in Everglades Restoration __________________________ 9
Partners-In-Flight Program _____________________________________ 10
Western Hemisphere Shorebird Reserve Network __________________ 10
North American Waterfowl Management Plan______________________ 10
Legal Context ____________________________________________________ 11
II. Planning Issues and Opportunities _____________________________________ 13
Introduction _________________________________________________________ 13
Summary Statements_________________________________________________ 13
Wildlife Habitat Management _______________________________________ 13
Refuge Protection _________________________________________________ 14
Public Use________________________________________________________ 14
Partnerships______________________________________________________ 15
Significant Resource Problems ______________________________________ 16
III. Refuge Environment ________________________________________________ 19
Physical Environment ________________________________________________ 19
Climate __________________________________________________________ 19
Physiography, Soils, and Geology ____________________________________ 19
Hydroperiod and Hydropattern _____________________________________ 20
Overview of Water Regulation ______________________________________ 21
Water Quality_____________________________________________________ 26
Nutrients ______________________________________________________ 26
Toxic Materials ________________________________________________ 28
Air Quality _______________________________________________________ 28
Biological Environment _______________________________________________ 29
Native Vegetation _________________________________________________ 29
Vegetative Communities_________________________________________ 29
Sloughs _______________________________________________________ 29
Wet Prairies ___________________________________________________ 29
Sawgrass ______________________________________________________ 29
Tree Islands ___________________________________________________ 29
Cypress Swamp ________________________________________________ 31
Cattail ________________________________________________________ 31
Wildflowers ____________________________________________________ 31
A.R.M. Loxahatchee
National Wildlife Refuge
Comprehensive
Conservation Plan
II A.R.M. Loxahatchee National Wildlife Refuge
Exotic Plants _____________________________________________________ 31
Melaleuca______________________________________________________ 32
Old World Climbing Fern ________________________________________ 36
Brazilian Pepper________________________________________________ 37
Australian Pine_________________________________________________ 38
Floating Exotic Plants __________________________________________ 38
Fish and Wildlife __________________________________________________ 39
Birds__________________________________________________________ 39
Waterfowl _____________________________________________________ 40
Wading Birds __________________________________________________ 40
Mammals ______________________________________________________ 41
Amphibians ____________________________________________________ 41
Reptiles _______________________________________________________ 42
Invertebrates __________________________________________________ 42
Fish___________________________________________________________ 43
Exotic Animal Species _____________________________________________ 43
Threatened and Endangered Species ________________________________ 44
Research Natural Area ____________________________________________ 45
Management of the Compartments __________________________________ 45
Ecology and Role of Fire in Plant Communities _______________________ 49
Fire Ecology ___________________________________________________ 49
Role of Fire in Everglades Plant Communities Over Time ___________ 49
Fire Risk and Suppression _______________________________________ 50
Socioeconomic Environment ___________________________________________ 50
Demographics ____________________________________________________ 50
Land Use ________________________________________________________ 51
Recreation Use ___________________________________________________ 51
National and Regional Context ___________________________________ 51
Refuge Recreation Use __________________________________________ 52
Recreation Economics___________________________________________ 55
Cultural Environment ________________________________________________ 56
Prehistoric Background ____________________________________________ 56
Belle Glade (Okeechobee) Area______________________________________ 56
Historic Period____________________________________________________ 56
IV. Management Direction _______________________________________________ 57
Introduction _________________________________________________________ 57
Refuge Vision________________________________________________________ 57
Refuge Goals ________________________________________________________ 58
Management Plan ____________________________________________________ 58
Summary Statement_______________________________________________ 58
Goals, Objectives, and Strategies ____________________________________ 59
Goal 1. Wildlife Habitat and Population Management ________________ 59
Goal 2. Resource Protection ______________________________________ 62
Goal 3. Public Use ______________________________________________ 65
Goal 4. Administration __________________________________________ 69
V. Plan Implementation _________________________________________________ 73
Project Summaries ___________________________________________________ 73
Wildlife Habitat and Population Management _________________________ 73
Staffing and Funding _________________________________________________ 81
Comprehensive Conservation Plan III
Partnership Opportunities_____________________________________________ 82
Step-Down Management Planning______________________________________ 83
Monitoring and Evaluation ____________________________________________ 86
Appendix A. Environmental Assessment
I. Purpose of and Need for Action_________________________________________ 89
II. Proposed Action _____________________________________________________ 90
III. Issues and Concerns_________________________________________________ 91
IV. Alternatives ________________________________________________________ 92
Description, Staffing Needs, and Costs __________________________________ 92
Alternative 1. Maintain Current Management (No Action Alternative) ___ 92
Alternative 2. Ecosystem Emphasis (Preferred Alternative) ___________ 102
Alternative 3. Biological Emphasis _________________________________ 106
Alternative 4. Public Use Emphasis ________________________________ 107
Alternatives Considered but Rejected _________________________________ 119
Responsiveness to Issues, Concerns, and Opportunities __________________ 119
V. Affected Environment _______________________________________________ 125
VI. Environmental Consequences________________________________________ 125
Effects on the Physical Environment __________________________________ 125
Soils ____________________________________________________________ 125
Hydrology_______________________________________________________ 126
Water Quality____________________________________________________ 127
Air Quality ______________________________________________________ 128
Noise Pollution___________________________________________________ 128
Aesthetics _______________________________________________________ 129
Facilities ________________________________________________________ 129
Effects on the Biological Environment _________________________________ 130
Vegetation and Exotic Plants ______________________________________ 130
Wildlife and Protected Species _____________________________________ 132
Research and Monitoring __________________________________________ 133
Wildlife in the Compartments ______________________________________ 133
Research Natural Area ___________________________________________ 134
Airboat Impacts__________________________________________________ 134
Fire Impacts_____________________________________________________ 136
Effects on Cultural and Historic Resources _____________________________ 139
Effects on Recreation, Environmental Education, and Interpretation ______ 140
Recreation ______________________________________________________ 140
Environmental Education and Interpretation ________________________ 143
Effects on the Socioeconomic Environment _____________________________ 144
Ecotourism ______________________________________________________ 144
Property Values__________________________________________________ 144
Tax Revenue ____________________________________________________ 144
Unavoidable Impacts ________________________________________________ 145
Effects Common to Alternatives ______________________________________ 146
Health and Safety ________________________________________________ 146
Regulatory Effects _______________________________________________ 146
Effects on Surrounding Lands _____________________________________ 146
Uncertainty of and Future Action Effects ___________________________ 146
Cumulative Effects _______________________________________________ 147
Controversy Over Effects _________________________________________ 147
Mitigation Measures _________________________________________________ 156
IV A.R.M. Loxahatchee National Wildlife Refuge
Wildlife Disturbance ______________________________________________ 156
Water Quality Disturbance ________________________________________ 157
User Group Conflicts _____________________________________________ 157
Effects on Adjacent Landowners ___________________________________ 158
Land Ownership and Site Development _____________________________ 158
Short-term Uses versus Long-term Productivity ________________________ 159
VII. Consultation and Coordination_____________________________________ 160
Appendix B. Glossary ____________________________________________________ 153
Appendix C. References and Literature Citations _______________________________ 169
Appendix D. Compatibility Determination _____________________________________ 179
Appendix E. Compliance Requirements ______________________________________ 189
Appendix F. Key Legislation/Policies ________________________________________ 191
Appendix G. Summary: Public Scoping Meeting________________________________ 193
Appendix H. Comment Packet and Sheet _____________________________________ 195
Appendix I. Summary: Comment Sheets______________________________________ 199
Appendix J. Public Issues Addressed But Not Allowed or are Pending _____________ 205
Appendix K. Flora and Fauna_______________________________________________ 213
Appendix L. Subtropical Florida Partners in Flight Bird
Conservation Plan: Section 2 Avifaunal Analysis_____________________ 235
Appendix M. Existing and Potential Partners__________________________________ 241
Appendix N. License Agreement ____________________________________________ 243
Appendix O. Staff Inventory and Monitoring Efforts _____________________________ 271
Appendix P. Budget Requests under Refuge Operating Needs System and Management
Maintenance System __________________________________________ 275
Appendix Q. Intra-Service Section 7 Biological Evaluation_______________________ 277
Appendix R. Comments and Service Responses to Draft Plan _____________________ 281
Comprehensive Conservation Plan V
1. Regional perspective for A.R.M. Loxahatchee National Wildlife Refuge ____ 5
2. Boundaries and potential buffer lands at A.R.M. Loxahatchee National
Wildlife Refuge______________________________________________________ 6
3. Upper Everglades Basin of importance to central Florida wintering
waterfowl, breeding mottled ducks and wood ducks ______________________ 8
4. Florida Everglades Ecosystem Subregion within the South
Florida Ecosystem__________________________________________________ 12
5. Major canals of the Central and South Florida Project which affect
water flow in and out of A.R.M. Loxahatchee National Wildlife Refuge
and the rest of the Everglades Ecosystem _____________________________ 22
6. The location of pump stations and spillways at A.R.M.
Loxahatchee National Wildlife Refuge_________________________________ 23
7. Water regulation schedule for Water Conservation Area 1,
A.R.M. Loxahatchee National Wildlife Refuge__________________________ 25
8. Vegetative communities of A.R.M. Loxahatchee National Wildlife Refuge__ 30
9. 1992 Melaleuca Aerial Survey Results _________________________________ 33
10. 1995 Melaleuca Aerial Survey Results _________________________________ 34
11. 1992 Old World Climbing Fern (Lygodium) Survey Results ______________ 37
12. Research Natural Area of A.R.M. Loxahatchee National Wildlife Refuge __ 46
13. The location of water control structures and pumps used at
A.R.M. Loxahatchee National Wildlife Refuge__________________________ 47
14. Current location of Compartments A, B, C, and D, Headquarters area,
Strazzulla Marsh and Hillsboro Recreation Area at A.R.M. Loxahatchee
National Wildlife Refuge ____________________________________________ 53
15. Proposed boundary expansion near the Headquarters area of
A.R.M. Loxahatchee National Wildlife Refuge__________________________ 64
16. Expanded public use opportunities at the
Headquarters area, A.R.M. Loxahatchee National Wildlife Refuge ________ 66
17. Expanded public use opportunities at Strazzulla
Marsh, A.R.M. Loxahatchee National Wildlife Refuge ___________________ 67
18. Public use opportunities and land use zones on the L-40 and L-39 Levees,
A.R.M. Loxahatchee National Wildlife Refuge__________________________ 70
19. Expanded public use opportunities and waterway
zones, A.R.M. Loxahatchee National Wildlife Refuge ____________________ 71
20. Proposed staffing plan for A.R.M. Loxahatchee National Wildlife Refuge __ 81
21. Alternative 1: Current public use accessibility, A.R.M. Loxahatchee
National Wildlife Refuge ____________________________________________ 94
22. Alternative 1: Public use areas at Headquarters area,
A.R.M. Loxahatchee National Wildlife Refuge__________________________ 95
23. Proposed boundary expansion near the Headquarters
of A.R.M. Loxahatchee National Wildlife Refuge _______________________ 97
24. Alternatives 2 and 4: Expanded public use opportunities at the
Headquarters area, A.R.M. Loxahatchee National Wildlife Refuge ________ 98
25. Alternatives 2 and 4: Expanded public use opportunities and
waterway zones, A.R.M. Loxahatchee National Wildlife Refuge __________ 99
26. Alternatives 2 and 4: Expanded public use opportunities at Strazzulla
Marsh, A.R.M. Loxahatchee National Wildlife Refuge __________________ 100
27. Alternatives 2 and 4: Public use opportunities and land use zones on the
L-40 and L-39 Levees, A.R.M. Loxahatchee National Wildlife Refuge ____ 101
28. Alternative 3: Public use opportunities with removal of
levees, A.R.M. Loxahatchee National Wildlife Refuge __________________ 108
29. Alternative 3: Reduced public use access, A.R.M. Loxahatchee
National Wildlife Refuge ___________________________________________ 109
Figures
VI A.R.M. Loxahatchee National Wildlife Refuge
1. Number of waterfowl observed during surveys in the refuge
interior from September to March 1989-1998 ____________________________ 40
2. Wading bird nest estimates on A.R.M. Loxahatchee
National Wildlife Refuge, 1992-1999 ___________________________________ 41
3. Socioeconomic profile of Palm Beach County, Florida, 1980-1990 ___________ 50
4. Agricultural summary highlights of Palm Beach County, Florida __________ 51
5. Highest Recreation use at Loxahatchee
National Wildlife Refuge, 98 fiscal year_________________________________ 52
6. Economic impacts of A.R.M. Loxahatchee National Wildlife Refuge, 1995___ 55
7. Southeast Region recreation expenditures______________________________ 55
8. Cost Summary of the Projects for the Refuge ___________________________ 79
9. Annual cost of proposed staff positions for A.R.M. Loxahatchee
National Wildlife Refuge _____________________________________________ 80
10. Step-Down Management Plans and completion dates, arranged by issue
sequence in the goals and objectives portion of the plan __________________ 83
11. Annual cost of staff positions for A.R.M. Loxahatchee National
Wildlife Refuge under Alternative 1, “maintain current management”______ 96
12. Annual cost of proposed staff positions for A.R.M. Loxahatchee
National Wildlife Refuge under Alternative 2, “ecosystem emphasis” _____ 105
13. Annual cost of proposed staff positions for A.R.M. Loxahatchee
National Wildlife Refuge under Alternative 3, “biological emphasis” ______ 110
14. Annual cost of proposed staff positions for A.R.M. Loxahatchee
National Wildlife Refuge under Alternative 4, “public use emphasis” ______ 113
15. A comparison of alternatives by management goals _____________________ 114
16. A comparison of the annual cost of proposed staff positions, including
operational and project costs, for A.R.M. Loxahatchee National
Wildlife Refuge under four alternatives _______________________________ 118
17. Alternatives considered but rejected and the rationale for rejection_______ 120
18. Responsiveness of the alternatives to issues and concerns expressed
at the public scoping meeting or through written comments______________ 121
19. A summary of the environmental consequences of all the alternatives _____ 148
20. Fauna of A.R.M. Loxahatchee National Wildlife Refuge (Exclusive of Birds) 213
21. Birds of A.R.M. Loxahatchee National Wildlife Refuge __________________ 219
22. Listed species at A.R.M. Loxahatchee National Wildlife Refuge __________ 226
23. Exotic animals of A.R.M. Loxahatchee National Wildlife Refuge _________ 228
24. Category I Exotic Plants found on A.R.M. Loxahatchee National
Wildlife Refuge ____________________________________________________ 230
25. Category II Exotic Plants found on A.R.M. Loxahatchee National
Wildlife Refuge ____________________________________________________ 230
26. Plants of the Cypress Swamp Boardwalk of A.R.M. Loxahatchee
National Wildlife Refuge (Partial List) ________________________________ 231
27. Wildflowers of A.R.M. Loxahatchee National Wildlife Refuge (Partial List) __233
28. Priority bird species for subtropical Florida: entry
criteria and selection rationale _______________________________________ 235
29. Species suites for A.R.M. Loxahatchee National Wildlife
Refuge based on present and potential habitat _________________________ 239
Tables
Guiding Principals of the
National Wildlife Refuge System
We are land stewards, guided by Aldo Leopold’s teachings that land is a community of life and that love and
respect for the land is an extension of ethics. We seek to reflect that land ethic in our stewardship and to
instill it in others.
Wild lands and the perpetuation of diverse and abundant wildlife are essential to the quality of the
American life.
We are public servants. We owe our employers, the American people, hard work, integrity, fairness, and a voice
in the protection of their trust resources.
Management, training from preservation to active manipulation of habitats and populations, is necessary to
achieve the missions of the National Wildlife Refuge System and the U.S. Fish and Wildlife Service.
Wildlife-dependent uses involving hunting, fishing, wildlife observation, wildlife photography, and environmental
education and interpretation, when compatible, are legitimate and appropriate uses of the National Wildlife
Refuge System.
Partnerships with those who want to help us meet our mission are welcome and indeed essential.
Employees are our most valuable resource. They are respected and deserve an empowering, mentoring, and
caring work environment.
We respect the rights, beliefs, and opinions of our neighbors.
Comprehensive Conservation Plan 1
Comprehensive Conservation Plan
I. Background
Introduction
The U.S. Fish and Wildlife Service is developing a Draft Comprehensive
Conservation Plan to guide refuge management and resource use at
A.R.M. Loxahatchee National Wildlife Refuge in southeastern Florida.
Contained in this draft plan is a description of the planning process,
general background on the refuge, desired future conditions, refuge
vision and goals, and the management actions necessary to achieve these
conditions.
Guiding the development of the plan is Part 602 (National Wildlife
Refuge System Planning) of the Fish and Wildlife Service Manual and the
National Wildlife Refuge System Improvement Act of 1997. An overriding
consideration reflected in the proposed plan is that fish and wildlife
conservation has first priority in refuge management; public uses are
allowed and encouraged as long as they are compatible with, or do not
detract from, this priority mission and the purposes for which the refuge
was established.
The major issues addressed in the plan include exotic species; biological
diversity; water quality and quantity; land use changes; habitat and
wildlife protection; recreational opportunities and access; and
environmental education and partnerships. Based on these issues, a range
of alternatives was identified that could be implemented within the next
15 years. From these alternatives, the Service has tentatively selected a
preferred alternative, which is described in the following pages.
This plan supports the National Wetlands Priority Conservation Plan;
the North American Waterfowl Management Plan; the Partners-in-Flight
Initiative; the Multi-Species Recovery Plan for South Florida; the
South Florida Ecosystem Plan, and the Comprehensive Everglades
Restoration Plan.
Purpose of and Need for the Plan
The purpose of the plan is to identify the role the refuge will play in
support of the mission of the National Wildlife Refuge System and to
provide guidance in refuge management and public use activities. The
plan articulates the Service’s management direction (goals, objectives,
and strategies) for the next 15 years (2000-2015).
The plan is needed to:
provide a clear statement regarding the future management of the
refuge;
provide refuge neighbors, visitors, the public, and government officials
with an understanding of the Service’s management actions on and
around the refuge;
ensure that the refuge’s management actions are consistent with the
mandates of the National Wildlife Refuge System;
provide long-term guidance and continuity for refuge management;
provide a basis for the development of budget requests on the refuge’s
operational, maintenance, and capital improvement needs; and
address the issues regarding the refuge’s license agreement with the
South Florida Water Management District, including issues relating
to modification of the agreement and management capabilities and
responsibilities.
Immature Kites
Photo © Betty Wargo
2 A.R.M. Loxahatchee National Wildlife Refuge
Planning Process
A Draft Comprehensive Conservation Plan/Environmental Assessment
was prepared in compliance with the National Wildlife Refuge System
Improvement Act of 1997, and the National Environmental Policy Act
of 1969. The Refuge System Improvement Act requires the Service
to actively seek public involvement in environmental planning such as
the preparation of environmental assessments and environmental impact
statements. It also requires the Service to seriously consider all reasonable
alternatives, including a “no action” alternative. These alternatives are
described in the Environmental Assessment (Appendix A).
In developing the refuge plan, the Service completed a 3-step
planning process, as follows:
(1) Established and organized a planning team for the purpose of
developing a refuge comprehensive conservation plan;
(2) Held a public meeting to identify the important issues, concerns, and
opportunities relating to the future management of the refuge; and
(3) Prepared a draft plan for public review and comment.
On July 14-15, 1998, the Service assembled a planning team at the refuge
headquarters to begin developing a draft plan for the refuge. The team
developed a vision statement for the refuge and identified a number of
issues and concerns that were likely to affect the management of the refuge.
The planning team also identified several goals for the future direction of
the refuge and planned the agenda for the first public scoping meeting.
The public scoping meeting was held in Boynton Beach, Florida, on
August 17, 1998. This meeting identified a variety of issues, concerns, and
opportunities concerning the management of the refuge. In addition, the
Service distributed comment sheets and evaluated responses from persons
who attended the public meeting as well as from those who could not
attend the meeting. The comments from the public scoping meeting and
those expressed on the comment sheets are summarized in Appendices G
and I, respectively. These comments and each alternative and response are
reflected in summary statements identified in Table 18.
Following the identification of the issues and opportunities, the planning
team began the process of preparing the draft plan and environmental
assessment. Information concerning the refuge’s physical, biological, and
socioeconomic environment was compiled and is described in Section III,
Refuge Environment.
At subsequent planning team meetings, the alternatives for the
management of the refuge were identified. Each alternative was described
as a set of objectives or management actions (Appendix A). The potential
impacts of each alternative on the physical, biological, cultural and historic,
and socioeconomic environments are also described in Appendix A.
The draft plan was distributed to officials of federal, state, and local
government agencies, private organizations, and the general public for
review and comment. A public meeting was held to present each
alternative and obtain verbal comments from the public. In addition,
a public meeting was held to present the draft plan. Comments were
collected for a period of 40 days. Those comments were integrated into the
final management plan (Section IV).
Comprehensive Conservation Plan
Comprehensive Conservation Plan 3
The U.S. Fish and Wildlife Service
The U.S. Fish and Wildlife Service is the primary federal agency
responsible for conserving, protecting, and enhancing the Nation’s fish
and wildlife populations and their habitats. Although the Service shares
this responsibility with other federal, state, tribal,
local, and private entities, it has specific trustee
responsibilities for migratory birds, threatened and
endangered species, anadromous fish, and certain
marine mammals, as well as for lands and waters
administered by the Service for the management and
protection of these resources.
As part of its mission, the Service operates more
than 520 national wildlife refuges covering more than
92 million acres. These areas comprise the National
Wildlife Refuge System, the world’s largest collection
of lands specifically managed for fish and wildlife. The
majority of these lands, 77 million acres, is in Alaska,
with the remaining 15 million acres spread across the
other 49 states and several island territories.
The National Wildlife Refuge System
The mission of the National Wildlife Refuge System,
as defined by the National Wildlife Refuge System
Improvement Act of 1997, is:
“to administer a national network of lands and waters
for the conservation, management, and where appropriate,
restoration of the fish, wildlife and plant resources and their
habitats within the United States for the benefit of present
and future generations of Americans.”
The Act establishes wildlife conservation as the
primary mission of the National Wildlife Refuge
System. Refuges will be managed to fulfill the mission
of the National Wildlife Refuge System, fulfill the
individual purpose of each refuge, and maintain the
biological integrity, diversity, and environmental health
of the system.
While wildlife will have first priority in refuge
management, wildlife-dependent recreation uses or
other uses may be allowed after they have been
determined, by the Refuge Manager, to be appropriate
and compatible uses. Further, wildlife-dependent recreation uses, namely
hunting, fishing, wildlife observation, wildlife photography, environmental
education and interpretation are legitimate and priority public uses, are
dependent upon healthy fish and wildlife populations and are to receive
enhanced consideration over other public uses in planning and management.
National wildlife refuges provide important habitat for native plants,
mammals, birds, fish, amphibians, reptiles, insects, and invertebrates.
They also play a vital role in preserving threatened and endangered
species. Refuges offer a wide variety of wildlife-dependent recreational
opportunities, and many have visitor centers, wildlife trails, and
environmental education programs. In 1995, 24.9 million people visited
national wildlife refuges to hunt, fish, observe and photograph wildlife,
and participate in educational and interpretive activities (U.S. Fish and
Wildlife Service, 1997a). As visitation increases, significant economic
benefits are generated to local communities. On a national basis, refuge
visitors contribute more than $400 million each year to local economies.
Comprehensive Conservation Plan
Tricolored Heron
USFWS Photo by Evelyn McGraw.
4 A.R.M. Loxahatchee National Wildlife Refuge
A.R.M. Loxahatchee National Wildlife Refuge
History
A.R.M. Loxahatchee National Wildlife Refuge, located 7 miles west of the
city of Boynton Beach, is the only remnant of the northern Everglades in
Palm Beach County, Florida (Figure 1). Unlike the name of many national
wildlife refuges, Loxahatchee’s name was changed in 1986 to include a
noted local conservationist Arthur R. Marshall. Most of the 147,392-acre
refuge is encompassed by Water Conservation Area 1, which is owned by
the State of Florida and is licensed to the Service.
To the northwest of the refuge is the Everglades Agricultural Area which
includes sugar cane farms, winter vegetable and sod farms, and cattle
ranches. The land east of the refuge is predominantly urban with the
exception of the agricultural lands of the East Coast Buffer area. To the
south and southwest of the refuge lie Water Conservation Areas 2 and 3,
and Everglades National Park--the only other remaining portions of the
Everglades fresh water marsh.
Beginning with the Swampland Act of 1845, and later the 1907 Everglades
Drainage Act, excessive drainage activities occurred in the Everglades
to pave the way for agriculture and development. To meet the ever-increasing
water needs of agriculture and population expansion, three
water storage areas called Water Conservation Areas 1, 2, and 3 (Figure
1), were constructed by the U.S. Army Corps of Engineers in the 1940s.
Bounded by levees and connected by a series of canals, these areas were
placed under the jurisdiction of what is now the South Florida Water
Management District, an agency of the State of Florida.
In 1951, a license agreement (Appendix N) between the South Florida
Water Management District and the Service, under the Migratory
Bird Conservation Act, enabled the establishment of the 143,238-acre
Loxahatchee National Wildlife Refuge at Water Conservation Area 1. This
“refuge interior” land, as it is called, is owned by the State of Florida,
but managed by the Service. The license agreement was later amended
to include the 1604-acre Strazzulla Marsh, which lies adjacent to Water
Conservation Area 1 (Figure 2).
In addition to the lands licensed from the District, the Fish and Wildlife
Service owns 2,550 acres to the east and west of the refuge interior. This
acreage is sub-divided into four management compartments--A, B, C, D,
and the Cypress Swamp. In total, the refuge currently includes 147,392
acres of northern Everglades habitat.
The refuge is currently managed by a staff of 20 permanent and 4
temporary/seasonal personnel. The permanent personnel include a project
leader, deputy project leader, a refuge operation specialist, 2 Everglades
Program Team members, 2 administrative staff, 3 law enforcement staff,
4 biological staff, 4 maintenance/operations staff, and 2 public use staff. In
fiscal year 1999, the refuge operated with a budget of $1,451,000 for payroll
and operation needs and received $357,000 in special funding authorized
by Congress to address the maintenance backlog. For fiscal year 2000, the
refuge was allocated $1,520,700 for payroll and operation needs and also
received $144,100 for projects authorized by Congress.
The refuge Headquarters Area is the main entrance for refuge
administration, education, and public access. It contains an entrance fee
booth, administration building, a visitor center, four permanent residences,
the Everglades Program Team office building, a vehicle storage building,
four sheds, and a maintenance complex. In addition to these administrative
facilities, the area contains three boat ramps, a floating boat house, seven
parking lots, a boardwalk, an observation tower, observation platform,
and a fishing platform. The Hillsboro Recreation Area, located at the
southernmost point on the refuge, contains a parking area and boat ramps.
White ibis colony
USFWS Photo by F. Broerman
Comprehensive Conservation Plan
Comprehensive Conservation Plan 5
Comprehensive Conservation Plan
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Figure 1. Regional perspective for A.R.M. Loxahatchee National Wildlife Refuge
6 A.R.M. Loxahatchee National Wildlife Refuge
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Figure 2. Boundaries and potential buffer lands at A.R.M. Loxahatchee National Wildlife Refuge
Comprehensive Conservation Plan
Comprehensive Conservation Plan 7
Purpose
The Migratory Bird Conservation Act of February 18, 1929, 45 Stat. 1222,
the Act of June 30, 1948, 62 Stat. 1171, 1176, authorizing the construction
of the Central and Southern Florida Flood Control Project and the Fish
and Wildlife Coordination Act of March 10, 1934, 48 Stat. 401, amended by
the Act of August 14, 1946, 60 Stat. 1080, authorized the establishment of
Loxahatchee National Wildlife Refuge on January 1, 1951.
The refuge was created by two agreements entered into by the
Department of the Interior. The first agreement is a General Plan with
the Florida Game and Fresh Water Fish Commission (now the Florida
Fish and Wildlife Conservation Commission) which permitted Water
Conservation Area 1 to be used by the Fish and Wildlife Service for
the national migratory bird management program. The second agreement
is a long term License from the Central and Southern Florida Flood
Control District (now the South Florida Water Management District)
which provided for the use of Water Conservation Area 1 by the Service
“as a Wildlife Management Area, to promote the conservation of wildlife,
fish, and game, and for other purposes embodying the principles and
objective of planned multiple land use.”
According to the Fish and Wildlife Coordination Act, this refuge
“...shall be administered by him (Secretary of the Interior) directly or
in accordance with cooperative agreements... and in accordance with
such rules and regulations for the conservation, maintenance, and
management of wildlife, resources thereof, and its habitat thereon....”
(16 USC § 664).
The Migratory Bird Conservation Act of 1929 states that the refuge is
to be “...for use as an inviolate sanctuary, or for any other management
purpose, for migratory birds.” (16 USC. § 715d). This purpose and
the mission of the National Wildlife Refuge System is fundamental
to determining the compatibility of proposed uses of the refuge. The
compatibility of these uses is discussed in Appendix D.
Ecosystem and North American Context
Role of Refuge in South Florida Ecosystem Plan:
In response to the complexity of the South Florida and Everglades
Ecosystems, a South Florida Ecosystem Plan was completed by the
Service’s South Florida Ecosystem Team. This plan identified the goals,
objectives, and strategies for this ecosystem and the major issues
associated with eight ecosystem sub-regions. The refuge, located in the
Florida Everglades ecosystem subregion (Figure 4), will make a significant
contribution to achieving the objectives of this plan. Consistent with
the South Florida Ecosystem Plan, the refuge will reduce exotic
species; manage water quality and quantity through partnerships;
inventory and monitor wildlife and habitat; enforce laws to protect
refuge resources; promote public awareness about the ecosystem; provide
wildlife-compatible recreation; and maintain facilities and equipment at or
above Service standards.
The Refuge Manager attends and participates in monthly working group
meetings of the South Florida Ecosystem Team, which is comprised of
Service field stations in an area from Ft. Myers to Vero Beach and south to
the Keys. This team works together to accomplish Service priorities which
include protection and management of federal trust species and combating
the ever increasing problem of exotic invasives.
During the past two years the refuge has taken an active role in
partnership efforts to protect and enhance habitats and wildlife both on
and off refuge. Staff members have participated on water preserve area
study teams designed to provide buffer lands east of the Everglades that
will provide short hydro-period wetlands, enable ground water recharge,
and capture water for storage and delivery to east coast populations. Staff
Comprehensive Conservation Plan
8 A.R.M. Loxahatchee National Wildlife Refuge
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Figure 3. Upper Everglades Basin of importance to central Florida wintering waterfowl, breeding mottled ducks
and wood ducks
Comprehensive Conservation Plan
Comprehensive Conservation Plan 9
Comprehensive Conservation Plan are also working closely with county and state efforts to provide wildlife
corridors and greenways connecting several of the large land management
areas. In addition, the refuge is an active participant in Palm-Net, a
network of federal, state, and county agencies and private organizations
working together to provide interpretation and environmental education
opportunities to the public.
Role of Refuge in Everglades Restoration:
The refuge is an important part of the overall Everglades ecosystem.
The refuge receives water flowing south from Lake Okeechobee
(S5-A Pump Station) and the Everglades Agricultural Area (S6 Pump
Station). Discussions of re-plumbing the Everglades have included
decompartmentalization including removal of the levees surrounding the
refuge. However, removing the western and southern levees would allow
water to flow south to Water Conservation Areas 2,3 and Everglades
National Park, but would result in less control over maintaining water in
the northern part of the system. In addition, because of land subsidence
north and west of the refuge, if the levees were removed, water would
flow north and west instead of the historic southerly direction and drain
the refuge. Model runs of decompartmentalization show a decrease in Lake
Okeechobee levels and a decrease in overall water supply leading to the
conclusion that at this time, removal of the levees would not be beneficial to
water supply or ecological values of the system or to the refuge. However,
as part of the restoration, agricultural drainage water that comes through
the S6 Pump Station would soon stop and it will be re-routed through the
new Stormwater Treatment Area 2, and into Water Conservation Area 2.
The construction of canals throughout the Everglades ecosystem, as a
whole, has changed historic sheet-flow patterns. Comparisons of newly
shot aerial photos to historical aerial photos show elongate tree islands
appear to be losing their overall appearance of a teardrop or a strand
shape. Studies indicate that loss of a consistent north to south water flow
over the refuge is one of the factors contributing to this landscape change
(Brandt 2000).
The refuge’s water regulation schedule, revised May 1995, has provided a
mechanism to keep water levels in the refuge from dropping below 14 ft.
NGVD. This schedule keeps the refuge from completely drying out every
year. Though periodic dry outs are part of the natural cycle, yearly dry
outs can reduce fish populations (prey for many species including wading
birds), reduce the number of apple snails available for snail kites, provide
additional areas for the germination and spread of exotic vegetation, and
increase fire risks. Since the adoption of the regulation schedule in 1995,
no major fires have occurred in the refuge, and the refuge experienced a
record year for wading bird nesting in 1999. Stormwater Treatment Areas
1 East and 1 West will assist hydropatterns by providing a ready reservoir
of low nutrient water that the refuge can draw from when needed.
Water quality and water quantity issues will continue to be major concerns
in the protection of the resource. Until there are assurances that water
entering the refuge is clean, options that put more (greater than recent
levels) dirty water into the refuge are not considered ecologically beneficial.
The existing water regulation schedules appear to be benefitting the
ecological system within the refuge. Protecting the resources in the
refuge contributes to overall Everglades restoration in that it helps to
maintain the spatial extent and heterogeneity of historic habitats. This will
contribute to the overall maintenance of system biological diversity.
The refuge is working cooperatively with the Corps of Engineers and South
Florida Water Management District to better manage water resources
in the context of multiple uses (needs for the environment, urban, and
agricultural uses), including the use of long term forecasting and rainfall
driven operations. Refuge personnel have, in the past and more recently,
10 A.R.M. Loxahatchee National Wildlife Refuge
increased participation in discussions of restudy and restoration alternatives
by participating in various committees and advisory groups including:
Alternative Evaluation Team coordinated by the Corps of Engineers
(disbanded 1999)
Restoration Coordination and Verification and subteams (i.e., Adaptive
Assessment Team, Regional Evaluation Team) coordinated by the Corps
of Engineers
Water Preserve Area
Technical Oversight Committee
Everglades Technical Advisory Committee
Partners-In-Flight Program:
Recent documentation of plummeting bird numbers, especially of migrant
passerines (Hagen and Johnston 1989, Finch and Stengel 1992) stimulated
the formation of Partners-In-Flight, an international organization to
address the needs of non-game migratory birds. The Service is one
member of the Partners-In-Flight Program that includes coordination
between federal, state and non-governmental agencies, industry, and
conservation groups to promote research, land protection, and education
about migratory birds.
The refuge is in the Atlantic Flyway, one of the primary migratory routes
of bird species that breed in temperate North America and winter in
the tropics of the Caribbean and South America. More than 116 species
of neotropical migrants have been recorded passing through the south
Florida ecosystem. More than 129 bird species migrate to the south Florida
ecosystem to overwinter, and another 132 species breed in the ecosystem.
Because this ecosystem is located near Cuba and the West Indies, it draws
Caribbean species that rarely appear elsewhere in North America.
In 1995, the Service prepared a list of migratory non-game birds of
management concern in the United States to stimulate a coordinated
effort by federal, state, and private agencies to develop and implement
comprehensive and integrated approaches for the management of selected
species (Tables 22 and 29). The south Florida ecosystem supports many of
these species (Appendix L).
Western Hemisphere Shorebird Reserve Network:
The refuge is also an important stopover location for many species of
migratory shorebirds and a nesting location for some shorebirds. Although
the refuge is not designated as a strategic migrational site by the Western
Hemisphere Shorebird Reserve Network, it does provide important foraging
habitat for these species and contributes survey data to the network.
North American Waterfowl Management Plan:
Since the first settlers arrived, more than 50 percent of the United States’
original 220 million acres of wetlands, upon which waterfowl depend,
have been destroyed often causing dramatic declines in numerous
waterfowl populations.
Although some populations have declined, waterfowl remain an
economically important group of migratory birds on the North American
continent. According to the 1996 National Survey of Fishing, Hunting and
Wildlife Associated Recreation, approximately 1.8 million people spent $740
million annually to hunt ducks, both on and off national wildlife refuges.
About 18.6 million people spent $2 billion observing, photographing, and
otherwise appreciating waterfowl throughout the United States, not just on
refuges (Fish and Wildlife Service, Division of Federal Aid).
Recognizing the importance of waterfowl and wetlands to North America
and the need for international cooperation to promote their well-being, the
Canadian and United States governments developed a strategy to restore
Comprehensive Conservation Plan
Mottled Ducks
USFWS Photo by B. Thomas, Jr
Comprehensive Conservation Plan 11
waterfowl populations to the levels of the 1970s through habitat protection,
restoration and enhancement. The strategy was documented in the North
American Waterfowl Management Plan, which was signed in 1986 by the
Canadian Minister of the Environment and the United States’ Secretary
of the Interior. This plan identified important waterfowl habitat areas,
established habitat and population goals, and established interstate/
international partnerships, called joint ventures, to implement plan goals.
In 1997, the Atlantic Coast Joint Venture continued to build upon its
firm foundation as Florida became its 17th state partner. Mid-winter data
indicate that 17 to 26 percent of the Atlantic Flyway’s January censussed
duck population winter in north and central Florida--an incidence greater
than in any other state in the flyway.
A small portion of the refuge lies within the Upper Everglades Basin,
which provides winter waterfowl habitat for scaup, ring-necked ducks,
redheads, blue- and green-winged teal, wigeon and fulvous-whistling
ducks, which are the most abundant species of waterfowl wintering in all of
Florida (Figure 3). It also provides breeding habitat for mottled and wood
ducks. Thus, the refuge has the potential of providing habitat for a portion
of the North American wintering population, especially for ring-necked
ducks. Management activities contribute towards meeting numerous goals
of the North American Waterfowl Management Plan.
The issue of high mercury levels found in resident fish and alligator body
burdens raises concerns about resident waterfowl. Population monitoring
and heavy metal testing is needed for mottled and wood ducks including
determining if a health advisory is needed regarding these locally
harvested species. It is assumed that because they are not fish-eating birds
the levels are within tolerance levels, however testing would be prudent.
Legal Context
In addition to the refuge’s authorizing legislation and the National Wildlife
Refuge System Improvement Act of 1997, the legal and policy guidance
for the operation of national wildlife refuges is contained in the documents
or acts listed below. For a description of the key legislation and policies,
see Appendix F.
Executive Order 1312- Invasive Species (2/3/99)
National Wildlife Refuge System Administration Act of 1966 (16 USC
668dd-668ee)
Refuge Recreation Act of 1962 (16 USC 460k-460k-4)
Title 50 of the Code of Federal Regulations, Subchapters B and C
The Refuge Manual
Fish and Wildlife Service Manual
Endangered Species Act of 1973 (16 USC 1531-1543)
Migratory Bird Hunting and Conservation Stamp Act (16 USC 718-718h)
Migratory Bird Treaty Act of 1918 (16 USC 703-712)
National Environmental Policy Act of 1969 (PL 91-190, 42 USC 4321-4347)
Bald Eagle Protection Act of 1940 (16 USC 668-668d)
American Indian Religious Freedom Act (P.L. 95-341, [1978], 92 Stat. 42
USC 1996)
Antiquities Act (P.L. 59-209, approved 6/8/1906, 34 Stat. 225, 16 USC
431-433)
Archaeological Resources Protection Act (P.L. 96-95 [10/31/1979], as
amended by P.L. 100-555 [10/18/1988] and P.L. 100-588 [11/3/1988], 93 Stat.
721, 16 USC 470 aa et seq.)
Archaeological and Historic Preservation Act (P.L. 93-291 [1974, 88 Stat.
1974], amending Reservoir Salvage Act, 16 USC 469)
Executive Order 13007 - Sacred Sites (5/24/1996)
National Historic Preservation Act (P.L. 89-665 [1966], 80 Stat. 95, as
amended by P.L. 96-515 [1980], 94 Stat. 2987; P.O. 102-575 Title 40 (1992),
106 Stat. 4600)
Native American Grave Protection and Repatriation Act (P.L. 101-601
(1990), 104 Stat. 3048, 25 USC 3000-3013, 18 USC 1170)
Comprehensive Conservation Plan
12 A.R.M. Loxahatchee National Wildlife Refuge
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Figure 4. Florida Everglades Ecosystem Subregion* within the South Florida Ecosystem
Comprehensive Conservation Plan
Comprehensive Conservation Plan 13
II. Planning Issues
and Opportunities
Introduction
Early in the development of this plan, the planning team developed a list of
issues and concerns that was likely to be associated with the management
of the refuge. This list was derived from team knowledge of the area, a
public scoping meeting, and written comments submitted by the public.
The scoping meeting, held on August 17, 1998, provided the public with
an opportunity to identify issues and concerns. Approximately 60 persons
attended the meeting. After a 15-minute presentation on the values of the
refuge, the meeting participants were divided into small groups, with the
group discussions facilitated by a consultant and planning team members.
The comments of each group, following a structured format, were recorded
on flip charts. These comments are summarized in Appendix G. Responses
from comment sheets, distributed at the scoping meeting and at the refuge,
and handwritten letters or postcards also provided information on issues
and concerns of importance to the public. The comment packet and a
summary of the comments are found in Appendix H and I, respectively.
Using the above sources, the planning team developed an abbreviated
list of statements reflecting major issues and concerns. While the
summary statements, presented below, may not be identical to the original
statements given by the public, the statements accurately reflect the
intended meaning of the comments received. The responsiveness of the
alternatives to these issues and concerns is summarized in Appendix A,
Table 18.
Summary Statements
Wildlife Habitat Management
The increasing number of exotic and invasive plant and animal species is
negatively impacting the refuge’s native wildlife and habitat.
Many local citizens were concerned about the threat exotic plants and
animals pose to the ecosystem and to the water supply. The public
mentioned such threats as melaleuca, Old World climbing fern, Brazilian
pepper, Australian pine, walking catfish, armored catfish, the bromeliad
weevil, and the Asian fresh-water marsh eel. It is their desire that the
refuge staff increase its efforts to protect native plants and wildlife from
these threats.
There is a need to improve the management of species and habitats to
enhance the native biodiversity and integrity of the refuge.
Many citizens stated that it is imperative that the refuge manage the
remaining portion of the Everglades to improve habitats and wildlife
populations. Some people believe that past refuge administration allowed
wildlife and habitats to decline and they wish that the land had been
better managed. Many people expressed frustration at the poor condition
of the impoundments and wondered why there was not more wildlife
available to observe on a year-round basis.
The degraded water quality and past water management practices (e.g.,
water quantities and schedules) are negatively impacting the refuge’s
ecosystem.
Many people stated the need for better water quality and an adequate
water quantity for the refuge. Other people, however, expressed concern
about having sufficient water for agriculture and the urban areas,
particularly if the refuge takes what it needs.
Comprehensive Conservation Plan
Boat-tailed grackle
USFWS Photo by Evelyn McGraw
14 A.R.M. Loxahatchee National Wildlife Refuge
Refuge Protection
The refuge is threatened by rapid development of residences, planned
communities, strip malls, or golf courses near its boundaries.
Many people recognize the threat of impending development and its
impact on the natural land base in the south Florida region, and they
wish to protect lands around the refuge from development. Some people
would like to see the current agricultural land use adjoining the refuge
perpetuated or more land set aside for natural areas. Many people
appeared to understand the fragility of the Everglades ecosystem and
support restoring adjacent lands to a native state.
The wildlife and habitats are not protected enough.
Many comments were written supporting greater protection of refuge
wildlife and habitats, especially for threatened and endangered species.
Many people expressed a desire to see the whole biological system
protected. Others believe that providing protection to wildlife and
habitat is especially important even if it means limiting public access.
Public Use
There are not enough opportunities to observe wildlife and its habitat in
a quiet, natural, non-developed environment.
Many people expressed their appreciation for the refuge, its relatively
quiet environment and its undeveloped nature. Since much of the land
in south Florida has been developed (in their view), the refuge needs
to stay relatively unsullied and quiet--a sanctuary for the public as
well as for wildlife. Some people wished that more areas of the refuge
(e.g., Strazzulla Marsh or the perimeter levee) were open so they could
participate in more passive wildlife observation. Many people said that
they don’t want any activity that will disrupt wildlife populations or
damage wildlife habitat.
There is a need for increased access to the refuge for active recreational
uses such as hiking, camping, bicycling, horseback riding, canoeing and
airboating.
A number of people would like to bicycle, horseback ride, ride all-terrain
vehicles, camp, hike, or airboat on the refuge. Many people believe that
many kinds of recreation have not been offered to the public and should
be. Due to the loss of natural lands in south Florida, people said they
want to be able to enjoy green space in ways other than walking.
There is a need to provide increased access to the refuge for hunting
waterfowl, deer, alligator, turkey, bear and frogs. The habitat needs
better management for fishing and hunting activities.
Some people expressed frustration that the refuge provides a limited
amount of access for hunting; further, they wished that the refuge
allowed the use of airboats, especially for that purpose. Others desired
a greater number of species to hunt. A number of individuals expressed
frustration with what they perceive to be poor management of hunting
and fishing habitat, especially with regard to the dense cattail growth at
the south end of the refuge.
Don’t allow airboating.
A number of people wrote comments and stated at the public meeting
that the refuge should not be opened to private airboating.
Comprehensive Conservation Plan
Comprehensive Conservation Plan 15
There is a need to provide access and improve/provide public use
facilities at the Hillsboro Recreation Area and at Strazzulla Marsh.
Many people expressed a desire for improved facilities and support
services at the Hillsboro area, located at the south end of the refuge.
The desired facilities and services should include a concession (with
interpretive tours, boat rentals, educational experiences), usable boat
ramps, telephones and restrooms. In addition, some people wished to
have access to Strazzulla Marsh. Many people were concerned about the
poor maintenance of the canoe trail and lack of additional access to the
refuge interior. A few people desired an access point at the north end of
the refuge to replace the closed “20-Mile Bend” access point.
There is a need to expand environmental education and interpretation,
highlighting the Everglades ecosystem.
Many people want to experience a greater number and variety of
environmental education programs on the refuge. Further, they want
their children to learn about the Everglades through the refuge. Some
people said that new exhibits are needed, which can be rotated, and
that facilities needed to be upgraded. Some citizens wished that the
refuge would provide more educational tours for school and senior citizen
groups, and summer camps.
Partnerships
There is a need for the refuge to develop partnerships with state, county
and community agencies, universities and educational institutions,
natural resource based organizations and other entities.
People think the refuge should work more closely with other natural
resource agencies and user groups. To enhance management, some
people believe there is a need to share equipment and knowledge
between agencies.
Take the refuge from the Fish and Wildlife Service and give it back to
the State (Florida Fish and Wildlife Conservation Commission).
Some people do not want the Service to manage Water Conservation
Area 1. Currently, a license agreement with the South Florida Water
Management District gives authority to the Service to manage wildlife
in keeping with its mission and establishing legislation, but the Water
Management District retains the authority to manage water for flood
control and water supply. These citizens feel the Agreement has been
violated regarding wildlife and habitat management and by public access.
Many of the public wish the refuge to develop ecotourism connections
with the business community.
Citizens recognize that the refuge is a tourist attraction and they
hope that it can continue to be beneficial to the local economy. Some
citizens wish the refuge would join the Chamber of Commerce and
create connections between hotels, recreational sport organizations and
businesses.
Comprehensive Conservation Plan
16 A.R.M. Loxahatchee National Wildlife Refuge
Significant Resource Problems
Water quality, quantity and timing, invasive and exotic plants and animals,
and urban growth are three major factors affecting the welfare of fish,
wildlife, and plants on the refuge and the surrounding ecosystem.
The defining element of the refuge and the whole of the Everglades is
water, its quality, delivery timing and amount. This unique ecosystem has
had a very low nutrient base for thousands of years and is comprised of
species that have evolved to thrive under low nutrient conditions. Human
activities adjacent to the refuge have introduced nutrients, primarily
fertilizers, which enhance the
growth of many non-indigenous and
invasive species to the detriment of
native species. Increased nutrients
change bacteria and algae, the
most basic level of the system.
This moves through the system
until it is visible as the vast
unnatural acreages of cattail.
Replacing the natural Everglades
marsh vegetation, these nuisance
species create monotypic stands
that are far less productive for
wildlife and lacks the visual appeal
of a diverse natural Everglades.
The reduction of nutrients entering
the refuge has been and will
continue to be a major issue.
The Everglades Nutrient Removal
Project was completed in October
1993 (South Florida Water
Management District 1997). This
serves three primary purposes: (1) to reduce phosphorus loads entering the
refuge and help minimize imbalances in Everglades flora and fauna; (2) to
develop the design, construction, operations, and maintenance experience
necessary for large scale application of flow-way treatment technology; and
(3) to implement optimal nutrient removal technology.
Currently the Everglades Nutrient Removal Project is in the last stages
of conversion to Stormwater Treatment Area 1-W. Stormwater Treatment
Area 1-E, through which surficial water will also be filtered, will be built
adjacent to the northeast portion of the refuge. The Everglades Nutrient
Removal Project, combined with best management farming practices, has
already achieved phosphorous levels below the original goal of 50 PPB.
However, a numeric standard still needs to be set for the amount of
phosphorus that no longer causes an imbalance to flora and fauna. To reach
this standard will require design and implementation of new technology.
The standard will not only provide a basis for assessing the financial
resources required to achieve water quality, but also a basis for monitoring.
Because the Everglades is no longer a free-flowing system that relies on
temporal weather patterns to sustain it, humans must now attempt to
provide water when and where the system can most benefit. The system
evolved under variation, not constant annual schedules. Unfortunately,
the water delivery system in place often exhibits its inadequacies in
the form of extended droughts or floods. Technology must be developed
and implemented to allow water managers to be more responsive to the
natural system’s needs and still meet the demands for water supply and
flood control.
Comprehensive Conservation Plan
Melaleuca
USFWS photo by M.D. Mattei
Comprehensive Conservation Plan 17
Exotic plants and animals are a tremendous threat to the ecosystem
and to its water supply. The refuge has the worst invasive exotic
plant problem in all of south Florida, and among the worst in National
Wildlife Refuge System, with more than 96,000 acres infested to varying
degrees. The amount of funding needed to control exotic plants is great,
especially considering the insufficient funding nationwide for national
wildlife refuges. A greater awareness is needed to maintain the refuge’s
biological integrity (See Refuge Environment, Exotic Plants).
Species such as melaleuca, Old World climbing fern, Brazilian pepper,
Australian pine, walking catfish, and now the South American armored
catfish, bromeliad weevil, and Asian fresh-water marsh eel are threats
that are currently visible. New “exotics” will undoubtedly appear as the
refuge struggles to find controls for established species. Exotics are not
just costly threats to the natural environment, but also to agriculture, land
development, business, and human health as well.
To meet the demands of a growing urban population, there is a
continuous stream of land use proposals for lands surrounding the
refuge. These proposed land use changes are often detrimental to the
natural environment and the aesthetics of the area. For example, power
transmission lines and high speed rail have been proposed to extend
through the refuge natural and public use areas. Solid waste disposal
sites have been proposed to abut the refuge boundary, which will bring
unsightly mountains of waste adjacent to public use areas and adversely
affect wildlife and water quality. However, the most likely immediate
threat is from the rapidly escalating speed with which strip malls
and housing developments are being built, especially adjacent to the
refuge borders.
Comprehensive Conservation Plan
18 A.R.M. Loxahatchee National Wildlife Refuge
Comprehensive Conservation Plan 19
III. Refuge Environment
Physical Environment
Climate
Located in the subtropical region of south Florida, the refuge’s climate is
hot and humid most of the year and the winters are mild. In general, there
are two seasons--wet and dry. The wet season occurs from late May to
late October. The refuge receives some of the highest amounts of rainfall
in south Florida (Gleason et al., 1975). While annual rainfall ranges from
40 to 83 inches, about 60 inches is typical. More than one-half of the
rainfall for the year occurs between June and September in the form
of thunderstorms. Only one hurricane (Irene in 1999) has made a direct
hit on the refuge since it was established, however, numerous hurricanes
and tropical storms have skirted it,
and these have caused large rainfall
events primarily during the months
of August to November. During the
dry season, November to May, rain
falls during the cold fronts which
average about seven per month
from December through March, but
the amount is significantly less than
during the wet season.
Winds prevail out of the southeast
and the average relative humidity is
75 percent. While air temperatures
at the refuge have ranged from
20°F to 101°F, the mean summer
temperature and the mean winter
temperature are 89°F and 56°F,
respectively. The combination of
humidity and temperature causes
heat indices to range from
105°-110°F in the summer. Since the
eastern edge of the refuge is located
within 12 miles of the Atlantic Ocean, temperatures are moderated. The
temperatures also are moderated by the surface water of the Everglades.
Physiography, Soils, and Geology
The refuge is composed of 147,392 acres of Everglades habitat. The refuge
is part of a large fresh water storage area connected by a series of canals
and levees, which were completed by the Corps of Engineers in 1960. The
underlying aquifer provides water into nearby coastal communities.
Underlying the refuge is a depression in the Fort Thompson Formation,
a limestone bedrock, which results in greater water depth than the
surrounding Everglades. Unlike other areas of the Everglades, where
there are only shallow layers of soil overlying the bedrock, soil depths in
the refuge range from 3.6 - 14.0 feet (Silveira 1996). The soil is primarily
Loxahatchee Peat which forms from the roots, rootlets, and rhizomes
of white water lily, and is an indication of a historic slough community.
The peat is lightly colored, fibrous and spongy, reflective of high organic
content. The low ash content of the soil is an indication of infrequent burns
in the area.
Loxahatchee Peat is found only in two areas in the Everglades--in the
refuge and Water Conservation Area 2, and in the western portions of
Water Conservation Area 3 and Shark Slough. Loxahatchee Peat is slightly
more acidic and has lower mineral content than other peats. The oldest
peat on the refuge has been dated at 4,800 years. Everglades Peat (formed
primarily from sawgrass) and Gandy Peat (formed from woody material,
especially associated with tree islands) also are present on the refuge.
Comprehensive Conservation Plan
USFWS Photo by S.D. Jewell
20 A.R.M. Loxahatchee National Wildlife Refuge
The refuge is on a gradual north to south slope which results in slowly
moving surface water sheet flow. The topography undulates throughout
the refuge, creating mounds and depressions that are covered by varying
depths of water. In addition, the refuge contains thousands of tree islands
which form when a layer of peat dislodges itself from the substrate and
floats to the surface. During periods of low water, tree islands become
rooted to the substrate. Plant succession occurs rapidly, and within about
three years, woody vegetation is established.
Hydroperiod and Hydropattern
Water flowing from the Everglades is vital to supplying surface water for
south Florida, replenishing the Florida and Biscayne aquifers, carrying
essential nutrients and clean, fresh water to estuaries, and supporting an
extremely rich and diverse assemblage of wildlife and plants. Changes
in the hydroperiods (the duration that an area is inundated) and
hydropatterns (the depth, timing, flow, and location of surface water) have
altered these vital wetland functions in the south Florida ecosystem.
Historically, surface water originating from rainfall and natural springs
flowed from the Kissimmee basin of central Florida. The spring fed
creeks formed rivers and filled Lake Okeechobee. From that point, water
overflowed the south end of the lake and began its southward sheet flow
to the southern tip of Florida. Historically, the precipitation that fell on the
Everglades could spread out over the entire area (>2,317 square miles). To
prevent flooding and provide agricultural and developmental land use, the
Corps of Engineers started the massive and historic effort of controlling
Everglades waters through construction of hundreds of miles of levees and
canals. This construction has not only constricted sheet flow, but also has
removed excess” Everglades water to the ocean. As the levees and canals
were completed, water ceased its natural flow through the Everglades;
rather, it was channeled through what is now the refuge. In contrast to the
past, water now enters the refuge from rainfall and three access points of
controlled surface flow.
Construction of the levees has had significant effects on the hydrology,
vegetation, and wildlife in the refuge. The shallow shorter hydroperiod
marshes that once surrounded the refuge have been replaced by deep-water
habitats along the canals. Lost is the mosaic of habitats that
provided, in the same year, the availability of deeper water slough
habitats for foraging snail kites and shallower marshes for foraging wading
birds (e.g., wood storks). Changes in the natural timing of water levels
affect wading bird feeding patterns, apple snail reproductive output, and
alligator nesting. In addition, changes in the patterns of water depth have
resulted in changes in aquatic vegetation and tree islands. In areas that
have become wetter, particularly along the rim canal, tree islands have
decreased in size and number (Brandt 2000), and more aquatic communities
have developed (Hagenbuck et al., 1974). In drier areas, particularly
the northern portion of the refuge, woody vegetation has become more
abundant (Hagenbuck et al., 1974). Lower water levels, particularly during
the dry season, increase the potential for fire and for fires to burn hotter,
resulting in more damage to vegetation and soils.
Another consequence of impoundment has been the reduction of water flow
through the refuge. A reduction in flow rates has changed the patterns
of nutrient transport, seed dispersal, soil accretion, or loss. Brandt(2000)
provided some evidence that changes in flow as well as hydroperiods and
depths have contributed to the changes in the patterns of tree islands in
the refuge. The importance of flow as a structuring process, as well as
hydroperiods, should be considered for the maintenance of the ecological
integrity of the refuge and the Everglades.
Comprehensive Conservation Plan
Comprehensive Conservation Plan 21
Timing and volume of water releases from the refuge also have influenced
lands and waterways east and south of the refuge. By sending water to
the eastern urban areas, water flowing southward through the Everglades
ecosystem is greatly reduced, resulting in increased salinity in Florida and
Biscayne Bays. Prior to June, in preparation for the hurricane season, the
Corps of Engineers releases a large volume of fresh water from the refuge
into the Atlantic Ocean. This heavy pulse of fresh water into the nearby
Atlantic Ocean dilutes the saline environment, creating negative affects on
fish and marine life. Because this water is released near the refuge, the
water cannot complete its historical sheet flow to the tip of south Florida.
The loss of fresh water to Florida Bay has created hyper-saline conditions,
which have negatively impacted the estuarine and bay production and the
entire fishing industry.
Overview of Water Regulation
Purpose:
A.R.M. Loxahatchee National Wildlife Refuge, also known as Water
Conservation Area 1, is part of the Corps of Engineers’ Central and
Southern Florida Project for Flood Control and other purposes (Figure 5).
Water levels in Water Conservation Area 1 are regulated by a schedule to
produce optimum benefits among competing interests. These interests are
flood control, water supply (agricultural, municipal, and industrial), fish
and wildlife enhancement, prevention of saltwater intrusion, and water
supply to Water Conservation Areas 2 and 3 and Everglades National
Park. To produce these benefits, the water level (elevation) in the refuge is
adjusted as the year progresses, either by a release of water from Water
Conservation Area 1, an intake of water from Lake Okeechobee, or by a
combination of water release and intake.
Water Intake:
The current major sources of water for the refuge are rainfall (56 percent),
the S-5A, G-251, G-310, and S-6 pump stations (40 percent), and ACME 1
and 2 pump stations (4 percent). These stations are located at the north,
west and east sides of the refuge (Figure 6). The S-5A station pumps water
from the West Palm Beach Canal; the G-251 and G-310 stations pump
water from the Stormwater Treatment Area 1-W; the S-6 station currently
pumps water to the Hillsboro Canal, but will soon be diverting all of this
water into STA-2; and the ACME 1 and 2 pump stations discharge water
from Basin B in the Village of Wellington area. The amount of water that
comes in from S-6 is approximately 155,000-acre feet per year of water
or 30 percent of the water that comes in through structures. This water
loss will be made up by increased flows through the S-5A station and
Stormwater Treatment Area 1-E and/or reduction in outflows from the
refuge. Without this compensation the refuge will be greatly impacted.
Occasionally, the refuge receives water by gravity from S-5A(S), a two-bay
gated spillway.
Of all the water coming into the refuge, 44 percent is artificially pumped
and the remaining 56 percent is natural rainfall. Approximately 91 percent
of the pumped water is drained from agricultural lands north and west
of the refuge, while the remainder, 9 percent, is from agricultural and
developed lands located east of the refuge through the ACME Stations
(Figure 6). The pumping stations remove an average of 3/4 of an inch of
agricultural area runoff per day from their respective drainage areas in the
Everglades Agricultural Area.
Comprehensive Conservation Plan
22 A.R.M. Loxahatchee National Wildlife Refuge
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Figure 5. Major canals of the Central and South Florida Project which affect water flow in and out of A.R.M.
Loxahatchee National Wildlife Refuge and the rest of the Everglades Ecosystem
Comprehensive Conservation Plan
Comprehensive Conservation Plan 23
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Figure 6. The location of pump stations and spillways at A.R.M. Loxahatchee National Wildlife Refuge
Comprehensive Conservation Plan
24 A.R.M. Loxahatchee National Wildlife Refuge
Water Release:
Water outlets from the refuge are the Lake Worth Drainage District and
ACME Stations on the east side of the refuge and the S-10 and S-39
spillways on the west side. Serving as a flood control gate, the S-10 consists
of three spillways--S-10A, S-10C, and S-10D. In addition, the South Florida
Water Management District operates S-10E, which consists of three 6-foot
diameter gated culverts, as an additional outlet from Water Conservation
Area 1 into Area 2A.
The primary purpose of the S-39 spillway is to make releases from the
refuge to supply water needs to the Hillsboro Canal during the dry season.
It also can be used to discharge excess water to the ocean when capacity is
available in the Hillsboro Canal and when the water is not needed in Water
Conservation Area 2 or 3. Water may also be released from the refuge
through S-5A north for irrigation in the Everglades Agricultural Area
when stages in canals in the C-51, L-10, L-12 or L-8 basins are low.
It is important to point out that both pumping in or release of water at a
maximum volume is usually detrimental to breeding wildlife populations.
Rapid changes in water depths do not allow some types of animals to
reproduce successfully. For example, the primary food source for the
endangered Everglades snail kite is
the apple snail. This invertebrate
crawls out of the water and lays
eggs on herbaceous plant stems.
If water rapidly rises, the eggs
are submerged and they die. Thus
a season’s worth of food supply
will be lost for limpkins, alligators
and other wildlife including the
Everglades snail kite. If water
levels fall too rapidly, fish
populations may not be able to find
sloughs or deeper water areas. The
fish get stranded and die; a major
component of the marsh food web
is reduced and large populations
of wildlife have insufficient food
supplies.
Refuge Water Regulation Schedule
As indicated earlier, the water
level in Water Conservation Area
1 is regulated to produce maximum
benefits among the various interests–flood control, water supply, fish and
wildlife, and prevention of salt water intrusion. To produce these benefits,
the water level in the refuge is adjusted as the year progresses, either by a
release of water from Water Conservation Area 1, an intake of water from
Lake Okeechobee, or by a combination of water release and intake. The
particular action taken to release, intake, or retain water is dependent upon
the water elevation in a given month. Water elevations, grouped into four
zones--A1 (Flood Control); A2, B (Water Supply); and C (Inactive) across
time, comprise the water regulation schedule (Figure 7).
Zone A1 is the flood control zone from January through June. When water
levels enter this zone, active water releases will be made due to flood
conditions. If, for example, the water level reached 17.5 feet in January,
water would be released through the S-10 spillway to achieve an elevation
of 17.2 feet or lower.
From July through December, attempts are made to maintain water levels
within Zone A2. In this zone, water levels in Water Conservation Area
1, which are linked with rainfall amounts and the water level at Lake
Okeechobee, are permitted to reach a maximum of 17.5 feet; “excess” water
Comprehensive Conservation Plan
Water management at Compartment D
USFWS Photo by B. Thomas Jr.
Comprehensive Conservation Plan 25
Comprehensive Conservation Plan
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Figure 7. Water regulation schedule for Water Conservation Area 1, A.R.M. Loxaxatchee National Wildlife Refuge1
is released from the S-10 and S-39 spillways. When additional water is needed
for Water Conservation Area 2A or other areas, it is released from Area 1,
depending on relative water level at Lake Okeechobee.
Zone B, the water supply zone, ranges from a minimum of 14.0 to 17.5
feet during the year. This is the zone targeted to be most beneficial to fish
and wildlife on the refuge. When Area 1 water levels are within this zone,
water supply releases are made from Area 1 as needed, in relation to the
water level at Lake Okeechobee.
For Zone C, when water levels drop to 14.0 feet or less, there would be
no net release of water from Area 1. Any water supply releases would be
preceded by an equivalent volume of inflow from the lake.
There have been temporary deviations from the regulation schedule during
excessive rainfall events that occurred in 1995, during the El Niño event
that occurred during the dry season, January through mid-May 1998, and
after Hurricane Irene in the fall of 1999. This allowed water to be stored in
Water Conservation Area 1, as well as A2.
Benefits of Water Regulation Schedule:
The refuge water regulation schedule is designed to generate the following
benefits to fish and wildlife and their habitats:
Increased water depth during the wet years in the northern portion of
the refuge;
Increased hydroperiod of interior marshes to avoid annual dryout;
Increased area of interior marsh which serves as nursery areas for
aquatic organisms;
Improvement in timing of winter stage drawdown to benefit wading birds;
Restoration of deep water habitats suitable for nesting Everglades
snail kites;
Greater water storage within the central and southern Florida project
system during wet and normal rainfall years;
26 A.R.M. Loxahatchee National Wildlife Refuge
Water Quality
Due to human activities during the last century, nutrients and toxic
substances are ubiquitous and an ever-increasing problem in the south
Florida environment. Nutrients and toxic substances from urban and
agricultural lands have degraded the relatively pristine lakes, streams,
estuaries, and bays of the region (McPherson and Halley 1997).
Nutrients:
Impacts on the Everglades
Fertilizers are widely used in south Florida to maintain high levels of
agricultural productivity. From July 1990 through June 1991, fertilizers
sold in south Florida contained 140,000 tons of inorganic nitrogen and
56,000 tons of phosphate (McPherson and Halley 1997). Nutrient loading
from urban areas and the Everglades Agricultural Area has significantly
increased nutrient concentrations, particularly phosphorus, in the water
conservation areas (Stober et al., 1996). Historically, the Everglades has
been deficient in nutrients with phosphorus concentrations averaging
10 parts per billion (Lodge 1994); if phosphorus exceeds 50 parts per
billion in the water conservation areas, there is a good chance that
eutrophrophication will occur.
Researchers have documented a variety of negative effects from increased
nutrients such as increased soil phosphorus content; changed periphyton
communities; loss of native sawgrass communities; increased organic
matter in water; reduced dissolved oxygen; conversion of wet prairie plant
communities to cattails; and loss of important habitats for wading birds
(Stober et al., 1996).
As indicated earlier, approximately 91 percent of the water pumped
into the refuge is drained from agricultural lands and developed lands
east of the refuge. High nutrient runoff (specifically phosphorus) from
agricultural lands is one of the most serious issues facing the refuge; this
runoff causes proliferation of cattails and other undesirable plant species
that negatively affect the ecosystem’s balance. Areas in the western,
southwestern, southern, and southeastern portions of the refuge continue to
be eutrophied by the influx of nutrients (Fish and Wildlife Service 1996a).
The refuge is unique in that most of the high nutrient water received
remains in the canals which surround the conservation area, instead of
flowing directly through the refuge itself. Some high nutrient water does
move into the refuge, but evidence indicates that it moves slowly and
affects only a limited distance of Everglades habitat near the canals
(McCormick, 1999). Much of the interior refuge water comes from rainfall.
Portions of Water Conservation Areas 2 and 3, and even Everglades
National Park, have been directly impacted through runoff entering into
the central portions of these areas.
The refuge’s water quality contrasts sharply with other Everglades
habitats. Using data from the Everglades Consolidated Report, the refuge
water quality differs (is lower) considerably from Water Conservation
Area 2 with regard to the following: alkalinity ( by a factor of 5), specific
conductivity (by a factor of 5), ammonia (by 63 percent), nitrate (by more
than 50 percent), calcium (by a factor of 5), magnesium (by a factor of 6),
sodium (by 478 percent), sulfate (by a factor of 16), chloride (by a factor of
5), and dissolved organic carbon (by 200 percent). However, the refuge has
more than twice the amount of iron as Water Conservation Area 2, and this
was listed as a concern in the report.
Comprehensive Conservation Plan
Comprehensive Conservation Plan 27
Comparison of phosphorus and nitrogen loadings (metric tons) as a percentage
from water years 1990-1999 (South Florida Water Management District 2000).
Area Mean Phosphorus Load Mean Nitrogen Load
Refuge 35 % 28 %
Water Conservation Area 2 23 % 21 %
Water Conservation Area 3 37 % 33 %
Everglades National Park 5 % 18 %
When comparing the sizes of the refuge with Water Conservation Area 3 and the Everglades
National Park, the refuge takes in much more phosphorus and nitrogen per acre.
Extensive cattail marshes are associated with chemical and hydrologic
imbalances derived from agriculture, or other impacted runoff waters
(Gleason et al., 1975). While cattails are not described in historical
accounts, or identified on early maps of the Everglades, cattails currently
occupy at least 6,000 acres of the refuge (Richardson et al., 1990); they
are also a persistent noxious weed in compartments, impoundments, and
borrow canals. The water used to regulate these areas originates from
the L-40 canal and is nutrient-rich, thereby contributing to the spread of
cattail. Thick stands of cattail obstruct wildlife use of these wetlands and
preclude wildlife-dependent recreation such as birding and photography.
Legal Action
In view of the adverse effects of nutrients on the Everglades, in 1988 the
U.S. Attorney for South Florida filed a lawsuit on behalf of the refuge and
Everglades National Park. The suit alleged that the State of Florida, by
neglecting to enforce its water quality standards, allowed high nutrient
runoff to enter Class III waters. In 1991, the State of Florida and the
Federal Government signed a Settlement Agreement which mandated
the development of a constructed wetland Everglades Nutrient Removal
project and six stormwater treatment areas to filter nutrient-rich water,
the application of Best Management Practices by farmers to reduce the
amount of nutrients originating from their lands, and the research and
development of supplemental technologies to enable water to meet the
Class III standard.
As indicated earlier, historic phosphorous loading in the northern
Everglades is believed to have averaged about 10 parts per billion
over time. To attain interim and long-term phosphorus targets, the
South Florida Water Management District constructed in 1994, as a
test method of removing phosphorous loads, a 3,700-acre wetland known
as the Everglades Nutrient Removal Project. This project achieved
its performance objectives based on 57 months of operational data
(August 94-April 99) All 12-month rolling, flow weighted total phosphorus
concentrations at the outflow were well below 50 PPB (Chimney et al.,
2000) This project makes an important contribution toward water quality
and the stormwater treatment areas are based on this project.
Thus far, two of the six stormwater treatment areas have been completed.
The Everglades Nutrient Removal Project is being incorporated into
the footprint of a larger Stormwater Treatment Area (1W) for a total
treatment area of 6,700 acres. Stormwater Treatment Area 1E, being
constructed by the Corps of Engineers, will be 5,350 acres. Together, the
stormwater treatment areas will straddle the north end of the refuge
filtering water being pumped from the S5A station. These two filtering
marshes, along with agricultural best management practices, will reduce
phosphorous values to an interim value less than 50 PPB. Long-term
values to be set by the Florida Environmental Regulatory Commission
will be accomplished through a combination of Best Management Practices,
optimization of the stormwater treatment areas, and appropriate new
technologies. The successful construction, maintenance, and operation of
stormwater treatment areas will be critical to ensuring water quality and
quantity to the refuge.
Comprehensive Conservation Plan
28 A.R.M. Loxahatchee National Wildlife Refuge
Comprehensive Conservation Plan Toxic Materials:
Pesticides and Herbicides
Pesticides have been widely used in south Florida’s agricultural and urban
areas to control insects, fungi, and other undesirable organisms. Since
Florida has year-round warm temperatures and a moist climate, vigorous
pest control is a necessity. Pesticide use per acre is ranked among the top
five in the nation; at the same time, agricultural production only ranks 30th
in the nation.
Pesticides vary in their toxicity, transport, and persistence. While
persistent pesticides (e.g., DDT, chlordane, dieldrin, and aldrin) have been
banned from Florida, their residues often become widely distributed and
are potentially hazardous to non-target biota (McPherson and Halley 1997).
By far the most frequently detected insecticides in both surface waters and
bottom sediments are the chlorinated hydrocarbons (Shahane 1994). Since
the late 1960s, persistent organochlorine pesticides have been detected in
fish, which are part of the Everglades food chain (Kolipinski and Higer
1969, McPherson 1973, Haag and McPherson 1997).
Chlorinated chemicals, such as polychlorinated biphenyls, dioxins, and
furans, which are used primarily in urban and industrial areas, pose a
serious threat not only to fish and wildlife but also to human populations
(Colborn et al., 1993). Although most uses of polychlorinated biphenyls
have been banned since the late 1970s, these persistent chemicals are still
found in the environment. In recent years, many organochlorine pesticides
and polychlorinated biphenyls have been linked to hormone disruption
and reproductive problems in aquatic invertebrates, fishes, birds, and
mammals (Colborn et al., 1993).
Herbicides, including atrazine, bromocil, simazine, 2-4-D, ametryn,
hexazinone, and diuron, which have the highest rate of application, are
among the most frequently detected herbicides in Florida’s surface waters
(Shahane 1994).
While the refuge shares the same challenges regarding some pesticides
with other Water Conservation Areas and Everglades National Park,
those pesticides of potential concern mainly for the refuge include
endosulfan, diurnon, endosulfan sulfate, and 2, 4-D. Three metals of
concern for the refuge include beryllium, iron, and mercury.
Mercury
Evidence of mercury contamination in fish and wildlife in south Florida
fresh water ecosystems is extensive. High mercury levels have been
detected in the endangered wood stork and other birds (Sundlof et al.,
1994). Scientists suspect that increased mercury exposure may partially
explain the 50-year decline in wading bird numbers. Fish and alligators
sampled in the Everglades have high mercury levels in their tissues (Ware
et al., 1990, Eisler 1987). In 1989, after discovering the extent and severity
of mercury in fish, the Florida State Health Officer advised fishermen to
avoid consumption of several species of fish in more than 1,000,000 acres of
the Everglades. The health advisory for the refuge is as follows:
“The Florida Department of Health and Rehabilitative Services has issued
a health advisory urging limited consumption of largemouth bass and
warmouth caught in certain portions of the Everglades due to excessive
accumulation of the element mercury. Fish caught in Water Conservation
Area 1 should not be eaten more than once per week by adults and not
more than once per month by children under 15 and pregnant women,
and fish caught in Water Conservation Areas 2 and 3 should not be eaten
at all.”
Air Quality
Air quality is not perceived to be as critical a concern as water
quality. However, research shows that some of the mercury in the
Everglades, generated from incinerators or power plants, is transported
there atmospherically.
Comprehensive Conservation Plan 29
Comprehensive Conservation Plan Biological Environment
Native Vegetation
Vegetative Communities
The native vegetative communities of the Everglades ecosystem found on
the refuge include sloughs, wet prairies, sawgrass, tree islands, cattail, and
Cypress swamp. Based on 1989 satellite imagery for the refuge interior,
these communities have been grouped into four groups, namely, marsh,
shrubs, tree islands, and cattail (Figure 8). These communities evolved in
a watery system that naturally had low nutrients. Numerous algae species
or periphyton growing on the submerged vegetation are the basis for all
aquatic life, providing food for a host of micro and macro invertebrates and
grazing fish species (Lodge 1994).
Sloughs
Sloughs are the deepest natural marsh communities in the Everglades.
During the rainy season, water depth in sloughs may exceed 3 feet, with
the annual average depth about 1 foot. The dominant vegetation includes
white water lily, floating heart, and spatterdock (Lodge 1994). Submergent
plants such as bladderwort, fanwort or chara are abundant (Fish and
Wildlife Service 1997c). Underlying sloughs is peat soil, which support fish
species and aquatic invertebrates.
Wet Prairies
In contrast to sloughs, wet prairies have shallower water levels and
are characterized by short emergent plants such as beakrushes, spike
rushes and red-root (Chapman, pers. comm.). Wet prairies are the most
prevalent vegetative community (approximately 50 percent land coverage)
in much of the central and eastern portions of the refuge, and are generally
found between sawgrass marshes and sloughs. This important vegetative
community provides prey for wading birds and the Everglades snail kite in
the form of fish, aquatic invertebrates and apple snails (Lodge 1994).
Sawgrass
The sawgrass community (25 percent land coverage) is characterized by
the saw-edged sedge that dominates this type of habitat. Sawgrass may
grow in solid stands, mosaics or interspersed with other species such as
wax myrtle and dahoon holly. Sawgrass areas often border tree islands,
separating them from the wet prairie (Lodge 1994).
Tree Islands
The northern portion of the refuge is characterized with thousands of tree
islands that range from less than 1 acre to more than 300 acres. There
is approximately 20 percent of the refuge interior covered with tree
islands. They are typically composed of an overstory of redbay and
dahoon holly with wax myrtle, buttonbush and cocoplum comprising a
dense midstory and numerous ferns in the understory. Tree islands form
when submerged peat patches rise to the water’s surface and small
plants become established followed by shrubs and trees. During drought
conditions, alligators wallow out a circular deep water refugia, called
“alligator holes.” Wind blown herbaceous seeds germinate on the exposed
peat and eventually woody vegetation grows on the edges and creates a
tree island with a “doughnut shape.” Alligator holes are very important
aquatic refugia during the dry season and are sources for fish and
other aquatic organisms’ population reestablishment after summer rain
rehydrates the ecosystem (Lodge 1994). A vast number of tree islands
have been impacted by invasive exotic plants.
30 A.R.M. Loxahatchee National Wildlife Refuge
Comprehensive Conservation Plan
Figure 8. Vegetative communities of A.R.M. Loxahatchee National Wildlife Refuge
(Adapted from Richardson et al., 1990)
Comprehensive Conservation Plan 31
Cypress Swamp
On the eastern edge of the refuge is a 400-acre cypress swamp community
which is composed of pond cypress trees, pond apple, myrsine, lichens and
ferns such as giant leather, sword, shield, strap, royal, resurrection and
swamp ferns. The moist microclimate of the cypress swamp also provides
for a profusion of epiphytes (air plants), such as cardinal, giant, reflexed
and twisted wild pine and Spanish moss. This cypress swamp is the largest
remaining remnant of a community on the east side of the Everglades
whose former range extended from Lake Okeechobee through Palm Beach
and northern Broward counties, south to Fort Lauderdale (Lodge 1994).
The cypress swamp includes 20 species of trees and shrubs, 20 herbs, 9
vines, 1 sedge, 14 ferns, 7 bromeliads and 2 lichens (Fish and Wildlife
Service 1987b). (See Appendix K).
Cattail
Two native species of cattail grow on the refuge. Naturally growing cattails
can be found surrounding wading bird colonies, roost tree islands, and
alligator holes. The cattail growth is dependent upon the intense pulse
of nutrients deposited by the concentration of nesting birds. After a tree
island is abandoned by nesting birds, cattails often die back because of
the loss of nutrients (Fish and Wildlife Service 1998c).In response to years
of artificially high levels of nutrients (phosphorous) in the water, a dense
stand of cattails has been established along the perimeter canal. Near the
S-6 water structure, monotypic stands of cattail growth are approximately
1⁄2 mile deep. This water, received from the S-5A and S-6 pump stations,
originates from the agricultural fields to the north and west of the refuge.
Attempts to reduce the nutrient load in water and lessen the negative
impacts to the refuge are on-going (see Part II, Significant Resource
Problems and Part III, Water Quality).
Wildflowers
At least 50 wildflower species (exotic and native) can be found in marsh
areas of the refuge (Fish and Wildlife Service 1987). Common types
found are Spanish needle, arrowhead, buttonbush, string and spider lilies,
elderberry, lizard’s tail and scorpiontail, pickerelweed and primrose willow.
Exotic Plants
Invasive exotic plants, such as Brazilian pepper, melaleuca, and Old World
climbing fern, pose a serious threat to the whole south Florida ecosystem,
to native plant communities, wildlife habitats, threatened and endangered
species, and species of special concern on the refuge. Floating exotic
plants, such as water lettuce and water hyacinth, threaten to clog refuge
canals restricting navigation, water flow, and water drainage. These alien
plants, lacking natural predators and insects to keep them in check,
rapidly expand forming dense, monotypic forests and thickets which are
undesirable to humans and wildlife. This degraded habitat has been proven
to support less species diversity than native plant habitats. Generally,
exotic plants in south Florida tend to establish in “disturbed” areas such as
abandoned farm fields, along roadways, canals, and drainage ditches, and in
wetlands which have been altered or stressed due to hydroperiod changes
(Ferriter 1998). Melaleuca and Old World climbing fern are, however, not
restricted to areas of disturbance. Since the climate and conditions of south
Florida are similar to conditions for melaleuca and Old World climbing fern
in their native countries, these plants have rapidly become established in
pristine areas. Management of invasive pest plants is one of the priorities
established by the South Florida Ecosystem Restoration Task Force.
As a result of these priorities, the task force and working group have
authorized and funded the Noxious Exotic Weed Task Team to develop
the comprehensive strategic plan for the management of exotic pest
plants in Florida (with emphasis on south Florida). The team members
are managers and scientists from key federal, state, and local agencies
that deal directly with exotic pest plants (Doren 1998). The State of
Florida Everglades Forever Act of 1994, requires the South Florida Water
Comprehensive Conservation Plan
32 A.R.M. Loxahatchee National Wildlife Refuge
Management District to coordinate with other state, local, and federal
government entities to manage exotic pest plants with emphasis in the
Everglades Protection Area (all areas from the Everglades Agricultural
Area south to the Everglades National Park).The Florida Chapter of Exotic
Pest Plant Council, established in 1982, documents the spread of exotic pest
plants and unifies the exchange of information between land management
agencies, research scientists, industry and other interest groups who are
concerned with the impacts of exotic plants in natural areas (Laroche 1994).
Category I plants are species that are currently invading and disrupting
native plant communities in Florida. The refuge has 21 Category I plants
(Table 24). Category II plants are species that have shown a potential to
disrupt native plant communities, and the refuge has at least nine of these
(Table 25).
Refuge staff will remain actively involved with organizations such as
the Florida Exotic Pest Plant Council, Southeast Florida Exotic Pest
Plant Council, and the South Florida Invasive Plant Working Group and
adopt the strategies for exotic plant management recommended by these
organizations. The refuge will update its melaleuca management plan by
2002 to incorporate the methods and strategies of the South Florida Water
Management District’s melaleuca management plan originally drafted in
1990. By following the strategies of this plan, the South Florida Water
Management District has almost completed initial treatments of melaleuca
on all their lands and surveys have indicated a 26 percent decrease in
melaleuca populations particularly in the water conservation areas and
Lake Okeechobee from a high of 488,000 acres in 1993, to 361,000 acres
in 1999.
Melaleuca
Melaleuca, a native of Australia, was originally introduced in southeast and
southwest Florida in 1906 (Meskimen 1962) as an ornamental plant. At
one time, people believed the tree could assist in draining water from the
Everglades because water is rapidly taken up, used in photosynthesis and
released into the air as a vapor (transpiration). It is thought that the area
that became the refuge and Ft. Meyers on Florida’s west coast were heavily
seeded by airplane. In the 1930s
and 1940s, trees were planted along
the rim canal of Lake Okeechobee
and at the Monroe station, Big
Cypress National Preserve (Laroche
1994). Although the greatest
concentrations are found in areas
of historical introductions, the
refuge has one of the highest
concentrations of melaleuca in all of
the south Florida ecosystem.
In Strazzulla Marsh, melaleuca has
invaded the cypress swamp and
domes, sawgrass, and wet prairies;
nearly 50 percent of this area has
been affected. In the refuge interior,
melaleuca has invaded native tree
islands, sawgrass, sloughs, and wet
prairies. The most recent aerial
survey in 1995, estimated that 49
percent (71,000 acres) of the refuge
interior was moderately to heavily
infested. Using 1992 data as a comparison, melaleuca is calculated to
be expanding at the rate of 10 acres per day. The history of melaleuca
throughout the Everglades ecosystem, including the refuge, is one of “an
explosion in slow motion” (Laroche 1994). From the 1960s to the early
1980s, melaleuca grew at an exponential rate. Areas occupied by a single,
isolated “pioneer” tree soon developed into acres of dense “heads” and
Melaleuca “hack and squirt”
Photo © John and Karen Hollingsworth
Comprehensive Conservation Plan
Comprehensive Conservation Plan 33
Comprehensive Conservation Plan
Figure 9. 1992 Melaleuca Aerial Survey Results
34 A.R.M. Loxahatchee National Wildlife Refuge
Figure 10. 1995 Melaleuca Aerial Survey Results
Comprehensive Conservation Plan
Comprehensive Conservation Plan 35
monotypic forests. By the mid- to late-1970s, melaleuca had spread to
all areas of the refuge. It was the Refuge Manager’s opinion that if
an effective treatment technique could not be found, melaleuca would
certainly take over the refuge.
With no natural enemies in south Florida, such as disease or insects to
control its spread, and an ideal growing climate, melaleuca now threatens
to permanently replace and eliminate native Everglades flora and fauna.
As indicated above, melaleuca primarily invades disturbed areas but
is particularly prevalent in Florida wetlands; i.e., the refuge, where
hydroperiods have been artificially shortened or altered. In addition to
the above effects, live melaleuca inhibits the use of prescribed fire as a
management tool since the volatile oils in melaleuca leaves would produce
intense, uncontrollable fires. Furthermore, the use of fire would generate a
massive seedfall which would allow the tree to become quickly established
in adjacent areas. The raging wildfire during the drought of 1989-90,
certainly contributed to the exponential spread of melaleuca in the refuge
interior. The primary management tool used at the refuge for the control
of melaleuca is herbicides. At the present time, the chief treatment method
involves felling mature trees using chainsaws followed by treatment with
50 percent Arsenal® diluted in water. Follow-up visits are necessary
to prevent reinfestation. Since an intensive herbicide program was
established in 1992, refuge staff have eradicated more than 2,209,000 of
these trees on refuge lands at an annual cost exceeding $200,000, funded
by the Service and the District. An estimated 6,400 acres have been
cleared of melaleuca. Unfortunately, refuge staff can only treat about
1⁄2- to 1-acre-per-day, which is having a limited effect on the 10-acre-per-day
advance of melaleuca on the refuge. Since herbicidal treatments are
labor intensive and costly and melaleuca can easily re-infest cleared areas,
biological control offers an alternative (Center et al., 1998).
In 1999, the refuge switched to using private contractors for exotic
plant control for both melaleuca and Old World climbing fern after
refuge staff consulted with the National Park Service, the Department of
Environmental Protection, the South Florida Water Management District,
and other local agencies and made the determination that using private
contractors was the most cost effective means to eradicate exotic plants.
To better incorporate the philosophy of an integrated pest management
approach, the refuge has increased its role and effort concerning public
outreach and awareness by identifying the dangers and risks associated
with the introduction of exotic plants. Programs by individuals directly
involved with exotic plant management are scheduled as part of the
“Calender of Events” at the visitor center and these presentations are
free to the general public. Refuge staff schedule programs and slide
presentations for environmental education groups and for local chapters of
national organizations such as the Audubon Society.
The refuge will continue to push for more exotic plant control funding, a
limiting factor to successful exotic plant management. This will be done by
keeping this issue a high priority and informing all levels of the Service
about resource impacts and budget needs. Several key refuge personnel
serve as members on regional invasive species teams and ecosystem
restoration task forces where key exotic plant issues are addressed.
The refuge’s exotic plant problems are frequently addressed in local and
national newspapers, magazines and on national and Service web sites.
Within the past few years, U.S. Department of Agriculture research
scientists have begun to research insects from Australia as possible
controls of melaleuca. The snout beetle, was released on the refuge and
other parts of south Florida in the spring of 1997. Unfortunately the
beetle cannot survive and reproduce in the wet habitat of the refuge. A
second biological control, the defoliating sawfly, is scheduled for release
in 2000. Shipments were sent to the quarantine facility in 1992-1993. The
Environmental Assessment is currently being reviewed pending approval
Comprehensive Conservation Plan
36 A.R.M. Loxahatchee National Wildlife Refuge
by the Service’s Washington Office. This sawfly offers the best hope for
melaleuca control. Both adults and larvae feed voraciously on foliage of the
tree eventually causing complete de-foliage. The insects entire life cycle
occurs on the melaleuca tree, above ground. Larva pupate within the bark
of the tree. Researchers have been reluctant to release this insect due to
its noticeable damage as many people still have melaleuca growing in their
yards as ornamentals. Additionally, its release has been delayed because
the larvae have proven to be toxic, when consumed in large quantities, by
some wildlife and domestic animals. Studies and research into this matter
are continuing at this time. Evidently the larvae store a toxic chemical in
their system as they feed (Lophrytonin) and it becomes more concentrated
as they age.
Alternative methods for exotic plant control on the refuge other than
chemical, physical
Object Description
| Rating | |
| Title | Arthur R. Marshall Loxahatchee National Wildlife Refuge Comprehensive Conservation Plan |
| Description | index.cpd |
| FWS Resource Links | http://library.fws.gov |
| Subject |
Document Wildlife refuges Planning |
| Location |
Region 4 Florida |
| FWS Site |
LOXAHATCHEE NATIONAL WILDLIFE REFUGE ARTHUR R. MARSHALL LOXAHATCHEE NATIONAL WILDLIFE REFUGE |
| Publisher | U.S. Fish and Wildlife Service |
| Date of Original | September 2000 |
| Type | Text |
| Format | |
| Source | NCTC Conservation Library |
| Rights | Public domain |
| File Size | 411 Bytes |
| Original Format | Document |
| Full Resolution File Size | 411 Bytes |
| Tag | Library-Source-CCPs |
| Date created | 2013-03-06 |
Description
| Title | Arthur R. Marshall Loxahatchee National Wildlife Refuge Comprehensive Conservation Plan |
| Description | loxahatchee.pdf |
| FWS Resource Links | http://library.fws.gov |
| Subject |
Document Wildlife refuges |
| Location |
Region 4 Florida |
| FWS Site |
LOXAHATCHEE NATIONAL WILDLIFE REFUGE ARTHUR R. MARSHALL LOXAHATCHEE NATIONAL WILDLIFE REFUGE |
| Publisher | U.S. Fish and Wildlife Service |
| Date of Original | September 2000 |
| Type | Text |
| Format | |
| Source | NCTC Conservation Library |
| Rights | Public domain |
| File Size | 20478113 Bytes |
| Original Format | Document |
| Length | 372 |
| Full Resolution File Size | 20478113 Bytes |
| Transcript | U.S. Fish & Wildlife Service Arthur R. Marshall Loxahatchee National Wildlife Refuge Comprehensive Conservation Plan USFWS Photo Arthur R. Marshall Loxahatchee National Wildlife Refuge 10216 Lee Road Boynton Beach, Fl 33437 Telephone: 561/732 3684 Fax: 561/369 7190 U.S. Fish & Wildlife Service 1 800/344 WILD http://www.fws.gov September 2000 Comprehensive Conservation Plan I Table of Contents I. Background __________________________________________________________ 1 Introduction __________________________________________________________ 1 Purpose of and Need for the Plan________________________________________ 1 Planning Process ______________________________________________________ 2 The U.S. Fish and Wildlife Service ______________________________________ 3 The National Wildlife Refuge System ____________________________________ 3 A.R.M. Loxahatchee National Wildlife Refuge ____________________________ 4 History ___________________________________________________________ 4 Purpose ___________________________________________________________ 7 Ecosystem and North American Context ______________________________ 7 Role of Refuge in South Florida Ecosystem Plan_____________________ 7 Role of Refuge in Everglades Restoration __________________________ 9 Partners-In-Flight Program _____________________________________ 10 Western Hemisphere Shorebird Reserve Network __________________ 10 North American Waterfowl Management Plan______________________ 10 Legal Context ____________________________________________________ 11 II. Planning Issues and Opportunities _____________________________________ 13 Introduction _________________________________________________________ 13 Summary Statements_________________________________________________ 13 Wildlife Habitat Management _______________________________________ 13 Refuge Protection _________________________________________________ 14 Public Use________________________________________________________ 14 Partnerships______________________________________________________ 15 Significant Resource Problems ______________________________________ 16 III. Refuge Environment ________________________________________________ 19 Physical Environment ________________________________________________ 19 Climate __________________________________________________________ 19 Physiography, Soils, and Geology ____________________________________ 19 Hydroperiod and Hydropattern _____________________________________ 20 Overview of Water Regulation ______________________________________ 21 Water Quality_____________________________________________________ 26 Nutrients ______________________________________________________ 26 Toxic Materials ________________________________________________ 28 Air Quality _______________________________________________________ 28 Biological Environment _______________________________________________ 29 Native Vegetation _________________________________________________ 29 Vegetative Communities_________________________________________ 29 Sloughs _______________________________________________________ 29 Wet Prairies ___________________________________________________ 29 Sawgrass ______________________________________________________ 29 Tree Islands ___________________________________________________ 29 Cypress Swamp ________________________________________________ 31 Cattail ________________________________________________________ 31 Wildflowers ____________________________________________________ 31 A.R.M. Loxahatchee National Wildlife Refuge Comprehensive Conservation Plan II A.R.M. Loxahatchee National Wildlife Refuge Exotic Plants _____________________________________________________ 31 Melaleuca______________________________________________________ 32 Old World Climbing Fern ________________________________________ 36 Brazilian Pepper________________________________________________ 37 Australian Pine_________________________________________________ 38 Floating Exotic Plants __________________________________________ 38 Fish and Wildlife __________________________________________________ 39 Birds__________________________________________________________ 39 Waterfowl _____________________________________________________ 40 Wading Birds __________________________________________________ 40 Mammals ______________________________________________________ 41 Amphibians ____________________________________________________ 41 Reptiles _______________________________________________________ 42 Invertebrates __________________________________________________ 42 Fish___________________________________________________________ 43 Exotic Animal Species _____________________________________________ 43 Threatened and Endangered Species ________________________________ 44 Research Natural Area ____________________________________________ 45 Management of the Compartments __________________________________ 45 Ecology and Role of Fire in Plant Communities _______________________ 49 Fire Ecology ___________________________________________________ 49 Role of Fire in Everglades Plant Communities Over Time ___________ 49 Fire Risk and Suppression _______________________________________ 50 Socioeconomic Environment ___________________________________________ 50 Demographics ____________________________________________________ 50 Land Use ________________________________________________________ 51 Recreation Use ___________________________________________________ 51 National and Regional Context ___________________________________ 51 Refuge Recreation Use __________________________________________ 52 Recreation Economics___________________________________________ 55 Cultural Environment ________________________________________________ 56 Prehistoric Background ____________________________________________ 56 Belle Glade (Okeechobee) Area______________________________________ 56 Historic Period____________________________________________________ 56 IV. Management Direction _______________________________________________ 57 Introduction _________________________________________________________ 57 Refuge Vision________________________________________________________ 57 Refuge Goals ________________________________________________________ 58 Management Plan ____________________________________________________ 58 Summary Statement_______________________________________________ 58 Goals, Objectives, and Strategies ____________________________________ 59 Goal 1. Wildlife Habitat and Population Management ________________ 59 Goal 2. Resource Protection ______________________________________ 62 Goal 3. Public Use ______________________________________________ 65 Goal 4. Administration __________________________________________ 69 V. Plan Implementation _________________________________________________ 73 Project Summaries ___________________________________________________ 73 Wildlife Habitat and Population Management _________________________ 73 Staffing and Funding _________________________________________________ 81 Comprehensive Conservation Plan III Partnership Opportunities_____________________________________________ 82 Step-Down Management Planning______________________________________ 83 Monitoring and Evaluation ____________________________________________ 86 Appendix A. Environmental Assessment I. Purpose of and Need for Action_________________________________________ 89 II. Proposed Action _____________________________________________________ 90 III. Issues and Concerns_________________________________________________ 91 IV. Alternatives ________________________________________________________ 92 Description, Staffing Needs, and Costs __________________________________ 92 Alternative 1. Maintain Current Management (No Action Alternative) ___ 92 Alternative 2. Ecosystem Emphasis (Preferred Alternative) ___________ 102 Alternative 3. Biological Emphasis _________________________________ 106 Alternative 4. Public Use Emphasis ________________________________ 107 Alternatives Considered but Rejected _________________________________ 119 Responsiveness to Issues, Concerns, and Opportunities __________________ 119 V. Affected Environment _______________________________________________ 125 VI. Environmental Consequences________________________________________ 125 Effects on the Physical Environment __________________________________ 125 Soils ____________________________________________________________ 125 Hydrology_______________________________________________________ 126 Water Quality____________________________________________________ 127 Air Quality ______________________________________________________ 128 Noise Pollution___________________________________________________ 128 Aesthetics _______________________________________________________ 129 Facilities ________________________________________________________ 129 Effects on the Biological Environment _________________________________ 130 Vegetation and Exotic Plants ______________________________________ 130 Wildlife and Protected Species _____________________________________ 132 Research and Monitoring __________________________________________ 133 Wildlife in the Compartments ______________________________________ 133 Research Natural Area ___________________________________________ 134 Airboat Impacts__________________________________________________ 134 Fire Impacts_____________________________________________________ 136 Effects on Cultural and Historic Resources _____________________________ 139 Effects on Recreation, Environmental Education, and Interpretation ______ 140 Recreation ______________________________________________________ 140 Environmental Education and Interpretation ________________________ 143 Effects on the Socioeconomic Environment _____________________________ 144 Ecotourism ______________________________________________________ 144 Property Values__________________________________________________ 144 Tax Revenue ____________________________________________________ 144 Unavoidable Impacts ________________________________________________ 145 Effects Common to Alternatives ______________________________________ 146 Health and Safety ________________________________________________ 146 Regulatory Effects _______________________________________________ 146 Effects on Surrounding Lands _____________________________________ 146 Uncertainty of and Future Action Effects ___________________________ 146 Cumulative Effects _______________________________________________ 147 Controversy Over Effects _________________________________________ 147 Mitigation Measures _________________________________________________ 156 IV A.R.M. Loxahatchee National Wildlife Refuge Wildlife Disturbance ______________________________________________ 156 Water Quality Disturbance ________________________________________ 157 User Group Conflicts _____________________________________________ 157 Effects on Adjacent Landowners ___________________________________ 158 Land Ownership and Site Development _____________________________ 158 Short-term Uses versus Long-term Productivity ________________________ 159 VII. Consultation and Coordination_____________________________________ 160 Appendix B. Glossary ____________________________________________________ 153 Appendix C. References and Literature Citations _______________________________ 169 Appendix D. Compatibility Determination _____________________________________ 179 Appendix E. Compliance Requirements ______________________________________ 189 Appendix F. Key Legislation/Policies ________________________________________ 191 Appendix G. Summary: Public Scoping Meeting________________________________ 193 Appendix H. Comment Packet and Sheet _____________________________________ 195 Appendix I. Summary: Comment Sheets______________________________________ 199 Appendix J. Public Issues Addressed But Not Allowed or are Pending _____________ 205 Appendix K. Flora and Fauna_______________________________________________ 213 Appendix L. Subtropical Florida Partners in Flight Bird Conservation Plan: Section 2 Avifaunal Analysis_____________________ 235 Appendix M. Existing and Potential Partners__________________________________ 241 Appendix N. License Agreement ____________________________________________ 243 Appendix O. Staff Inventory and Monitoring Efforts _____________________________ 271 Appendix P. Budget Requests under Refuge Operating Needs System and Management Maintenance System __________________________________________ 275 Appendix Q. Intra-Service Section 7 Biological Evaluation_______________________ 277 Appendix R. Comments and Service Responses to Draft Plan _____________________ 281 Comprehensive Conservation Plan V 1. Regional perspective for A.R.M. Loxahatchee National Wildlife Refuge ____ 5 2. Boundaries and potential buffer lands at A.R.M. Loxahatchee National Wildlife Refuge______________________________________________________ 6 3. Upper Everglades Basin of importance to central Florida wintering waterfowl, breeding mottled ducks and wood ducks ______________________ 8 4. Florida Everglades Ecosystem Subregion within the South Florida Ecosystem__________________________________________________ 12 5. Major canals of the Central and South Florida Project which affect water flow in and out of A.R.M. Loxahatchee National Wildlife Refuge and the rest of the Everglades Ecosystem _____________________________ 22 6. The location of pump stations and spillways at A.R.M. Loxahatchee National Wildlife Refuge_________________________________ 23 7. Water regulation schedule for Water Conservation Area 1, A.R.M. Loxahatchee National Wildlife Refuge__________________________ 25 8. Vegetative communities of A.R.M. Loxahatchee National Wildlife Refuge__ 30 9. 1992 Melaleuca Aerial Survey Results _________________________________ 33 10. 1995 Melaleuca Aerial Survey Results _________________________________ 34 11. 1992 Old World Climbing Fern (Lygodium) Survey Results ______________ 37 12. Research Natural Area of A.R.M. Loxahatchee National Wildlife Refuge __ 46 13. The location of water control structures and pumps used at A.R.M. Loxahatchee National Wildlife Refuge__________________________ 47 14. Current location of Compartments A, B, C, and D, Headquarters area, Strazzulla Marsh and Hillsboro Recreation Area at A.R.M. Loxahatchee National Wildlife Refuge ____________________________________________ 53 15. Proposed boundary expansion near the Headquarters area of A.R.M. Loxahatchee National Wildlife Refuge__________________________ 64 16. Expanded public use opportunities at the Headquarters area, A.R.M. Loxahatchee National Wildlife Refuge ________ 66 17. Expanded public use opportunities at Strazzulla Marsh, A.R.M. Loxahatchee National Wildlife Refuge ___________________ 67 18. Public use opportunities and land use zones on the L-40 and L-39 Levees, A.R.M. Loxahatchee National Wildlife Refuge__________________________ 70 19. Expanded public use opportunities and waterway zones, A.R.M. Loxahatchee National Wildlife Refuge ____________________ 71 20. Proposed staffing plan for A.R.M. Loxahatchee National Wildlife Refuge __ 81 21. Alternative 1: Current public use accessibility, A.R.M. Loxahatchee National Wildlife Refuge ____________________________________________ 94 22. Alternative 1: Public use areas at Headquarters area, A.R.M. Loxahatchee National Wildlife Refuge__________________________ 95 23. Proposed boundary expansion near the Headquarters of A.R.M. Loxahatchee National Wildlife Refuge _______________________ 97 24. Alternatives 2 and 4: Expanded public use opportunities at the Headquarters area, A.R.M. Loxahatchee National Wildlife Refuge ________ 98 25. Alternatives 2 and 4: Expanded public use opportunities and waterway zones, A.R.M. Loxahatchee National Wildlife Refuge __________ 99 26. Alternatives 2 and 4: Expanded public use opportunities at Strazzulla Marsh, A.R.M. Loxahatchee National Wildlife Refuge __________________ 100 27. Alternatives 2 and 4: Public use opportunities and land use zones on the L-40 and L-39 Levees, A.R.M. Loxahatchee National Wildlife Refuge ____ 101 28. Alternative 3: Public use opportunities with removal of levees, A.R.M. Loxahatchee National Wildlife Refuge __________________ 108 29. Alternative 3: Reduced public use access, A.R.M. Loxahatchee National Wildlife Refuge ___________________________________________ 109 Figures VI A.R.M. Loxahatchee National Wildlife Refuge 1. Number of waterfowl observed during surveys in the refuge interior from September to March 1989-1998 ____________________________ 40 2. Wading bird nest estimates on A.R.M. Loxahatchee National Wildlife Refuge, 1992-1999 ___________________________________ 41 3. Socioeconomic profile of Palm Beach County, Florida, 1980-1990 ___________ 50 4. Agricultural summary highlights of Palm Beach County, Florida __________ 51 5. Highest Recreation use at Loxahatchee National Wildlife Refuge, 98 fiscal year_________________________________ 52 6. Economic impacts of A.R.M. Loxahatchee National Wildlife Refuge, 1995___ 55 7. Southeast Region recreation expenditures______________________________ 55 8. Cost Summary of the Projects for the Refuge ___________________________ 79 9. Annual cost of proposed staff positions for A.R.M. Loxahatchee National Wildlife Refuge _____________________________________________ 80 10. Step-Down Management Plans and completion dates, arranged by issue sequence in the goals and objectives portion of the plan __________________ 83 11. Annual cost of staff positions for A.R.M. Loxahatchee National Wildlife Refuge under Alternative 1, “maintain current management”______ 96 12. Annual cost of proposed staff positions for A.R.M. Loxahatchee National Wildlife Refuge under Alternative 2, “ecosystem emphasis” _____ 105 13. Annual cost of proposed staff positions for A.R.M. Loxahatchee National Wildlife Refuge under Alternative 3, “biological emphasis” ______ 110 14. Annual cost of proposed staff positions for A.R.M. Loxahatchee National Wildlife Refuge under Alternative 4, “public use emphasis” ______ 113 15. A comparison of alternatives by management goals _____________________ 114 16. A comparison of the annual cost of proposed staff positions, including operational and project costs, for A.R.M. Loxahatchee National Wildlife Refuge under four alternatives _______________________________ 118 17. Alternatives considered but rejected and the rationale for rejection_______ 120 18. Responsiveness of the alternatives to issues and concerns expressed at the public scoping meeting or through written comments______________ 121 19. A summary of the environmental consequences of all the alternatives _____ 148 20. Fauna of A.R.M. Loxahatchee National Wildlife Refuge (Exclusive of Birds) 213 21. Birds of A.R.M. Loxahatchee National Wildlife Refuge __________________ 219 22. Listed species at A.R.M. Loxahatchee National Wildlife Refuge __________ 226 23. Exotic animals of A.R.M. Loxahatchee National Wildlife Refuge _________ 228 24. Category I Exotic Plants found on A.R.M. Loxahatchee National Wildlife Refuge ____________________________________________________ 230 25. Category II Exotic Plants found on A.R.M. Loxahatchee National Wildlife Refuge ____________________________________________________ 230 26. Plants of the Cypress Swamp Boardwalk of A.R.M. Loxahatchee National Wildlife Refuge (Partial List) ________________________________ 231 27. Wildflowers of A.R.M. Loxahatchee National Wildlife Refuge (Partial List) __233 28. Priority bird species for subtropical Florida: entry criteria and selection rationale _______________________________________ 235 29. Species suites for A.R.M. Loxahatchee National Wildlife Refuge based on present and potential habitat _________________________ 239 Tables Guiding Principals of the National Wildlife Refuge System We are land stewards, guided by Aldo Leopold’s teachings that land is a community of life and that love and respect for the land is an extension of ethics. We seek to reflect that land ethic in our stewardship and to instill it in others. Wild lands and the perpetuation of diverse and abundant wildlife are essential to the quality of the American life. We are public servants. We owe our employers, the American people, hard work, integrity, fairness, and a voice in the protection of their trust resources. Management, training from preservation to active manipulation of habitats and populations, is necessary to achieve the missions of the National Wildlife Refuge System and the U.S. Fish and Wildlife Service. Wildlife-dependent uses involving hunting, fishing, wildlife observation, wildlife photography, and environmental education and interpretation, when compatible, are legitimate and appropriate uses of the National Wildlife Refuge System. Partnerships with those who want to help us meet our mission are welcome and indeed essential. Employees are our most valuable resource. They are respected and deserve an empowering, mentoring, and caring work environment. We respect the rights, beliefs, and opinions of our neighbors. Comprehensive Conservation Plan 1 Comprehensive Conservation Plan I. Background Introduction The U.S. Fish and Wildlife Service is developing a Draft Comprehensive Conservation Plan to guide refuge management and resource use at A.R.M. Loxahatchee National Wildlife Refuge in southeastern Florida. Contained in this draft plan is a description of the planning process, general background on the refuge, desired future conditions, refuge vision and goals, and the management actions necessary to achieve these conditions. Guiding the development of the plan is Part 602 (National Wildlife Refuge System Planning) of the Fish and Wildlife Service Manual and the National Wildlife Refuge System Improvement Act of 1997. An overriding consideration reflected in the proposed plan is that fish and wildlife conservation has first priority in refuge management; public uses are allowed and encouraged as long as they are compatible with, or do not detract from, this priority mission and the purposes for which the refuge was established. The major issues addressed in the plan include exotic species; biological diversity; water quality and quantity; land use changes; habitat and wildlife protection; recreational opportunities and access; and environmental education and partnerships. Based on these issues, a range of alternatives was identified that could be implemented within the next 15 years. From these alternatives, the Service has tentatively selected a preferred alternative, which is described in the following pages. This plan supports the National Wetlands Priority Conservation Plan; the North American Waterfowl Management Plan; the Partners-in-Flight Initiative; the Multi-Species Recovery Plan for South Florida; the South Florida Ecosystem Plan, and the Comprehensive Everglades Restoration Plan. Purpose of and Need for the Plan The purpose of the plan is to identify the role the refuge will play in support of the mission of the National Wildlife Refuge System and to provide guidance in refuge management and public use activities. The plan articulates the Service’s management direction (goals, objectives, and strategies) for the next 15 years (2000-2015). The plan is needed to: provide a clear statement regarding the future management of the refuge; provide refuge neighbors, visitors, the public, and government officials with an understanding of the Service’s management actions on and around the refuge; ensure that the refuge’s management actions are consistent with the mandates of the National Wildlife Refuge System; provide long-term guidance and continuity for refuge management; provide a basis for the development of budget requests on the refuge’s operational, maintenance, and capital improvement needs; and address the issues regarding the refuge’s license agreement with the South Florida Water Management District, including issues relating to modification of the agreement and management capabilities and responsibilities. Immature Kites Photo © Betty Wargo 2 A.R.M. Loxahatchee National Wildlife Refuge Planning Process A Draft Comprehensive Conservation Plan/Environmental Assessment was prepared in compliance with the National Wildlife Refuge System Improvement Act of 1997, and the National Environmental Policy Act of 1969. The Refuge System Improvement Act requires the Service to actively seek public involvement in environmental planning such as the preparation of environmental assessments and environmental impact statements. It also requires the Service to seriously consider all reasonable alternatives, including a “no action” alternative. These alternatives are described in the Environmental Assessment (Appendix A). In developing the refuge plan, the Service completed a 3-step planning process, as follows: (1) Established and organized a planning team for the purpose of developing a refuge comprehensive conservation plan; (2) Held a public meeting to identify the important issues, concerns, and opportunities relating to the future management of the refuge; and (3) Prepared a draft plan for public review and comment. On July 14-15, 1998, the Service assembled a planning team at the refuge headquarters to begin developing a draft plan for the refuge. The team developed a vision statement for the refuge and identified a number of issues and concerns that were likely to affect the management of the refuge. The planning team also identified several goals for the future direction of the refuge and planned the agenda for the first public scoping meeting. The public scoping meeting was held in Boynton Beach, Florida, on August 17, 1998. This meeting identified a variety of issues, concerns, and opportunities concerning the management of the refuge. In addition, the Service distributed comment sheets and evaluated responses from persons who attended the public meeting as well as from those who could not attend the meeting. The comments from the public scoping meeting and those expressed on the comment sheets are summarized in Appendices G and I, respectively. These comments and each alternative and response are reflected in summary statements identified in Table 18. Following the identification of the issues and opportunities, the planning team began the process of preparing the draft plan and environmental assessment. Information concerning the refuge’s physical, biological, and socioeconomic environment was compiled and is described in Section III, Refuge Environment. At subsequent planning team meetings, the alternatives for the management of the refuge were identified. Each alternative was described as a set of objectives or management actions (Appendix A). The potential impacts of each alternative on the physical, biological, cultural and historic, and socioeconomic environments are also described in Appendix A. The draft plan was distributed to officials of federal, state, and local government agencies, private organizations, and the general public for review and comment. A public meeting was held to present each alternative and obtain verbal comments from the public. In addition, a public meeting was held to present the draft plan. Comments were collected for a period of 40 days. Those comments were integrated into the final management plan (Section IV). Comprehensive Conservation Plan Comprehensive Conservation Plan 3 The U.S. Fish and Wildlife Service The U.S. Fish and Wildlife Service is the primary federal agency responsible for conserving, protecting, and enhancing the Nation’s fish and wildlife populations and their habitats. Although the Service shares this responsibility with other federal, state, tribal, local, and private entities, it has specific trustee responsibilities for migratory birds, threatened and endangered species, anadromous fish, and certain marine mammals, as well as for lands and waters administered by the Service for the management and protection of these resources. As part of its mission, the Service operates more than 520 national wildlife refuges covering more than 92 million acres. These areas comprise the National Wildlife Refuge System, the world’s largest collection of lands specifically managed for fish and wildlife. The majority of these lands, 77 million acres, is in Alaska, with the remaining 15 million acres spread across the other 49 states and several island territories. The National Wildlife Refuge System The mission of the National Wildlife Refuge System, as defined by the National Wildlife Refuge System Improvement Act of 1997, is: “to administer a national network of lands and waters for the conservation, management, and where appropriate, restoration of the fish, wildlife and plant resources and their habitats within the United States for the benefit of present and future generations of Americans.” The Act establishes wildlife conservation as the primary mission of the National Wildlife Refuge System. Refuges will be managed to fulfill the mission of the National Wildlife Refuge System, fulfill the individual purpose of each refuge, and maintain the biological integrity, diversity, and environmental health of the system. While wildlife will have first priority in refuge management, wildlife-dependent recreation uses or other uses may be allowed after they have been determined, by the Refuge Manager, to be appropriate and compatible uses. Further, wildlife-dependent recreation uses, namely hunting, fishing, wildlife observation, wildlife photography, environmental education and interpretation are legitimate and priority public uses, are dependent upon healthy fish and wildlife populations and are to receive enhanced consideration over other public uses in planning and management. National wildlife refuges provide important habitat for native plants, mammals, birds, fish, amphibians, reptiles, insects, and invertebrates. They also play a vital role in preserving threatened and endangered species. Refuges offer a wide variety of wildlife-dependent recreational opportunities, and many have visitor centers, wildlife trails, and environmental education programs. In 1995, 24.9 million people visited national wildlife refuges to hunt, fish, observe and photograph wildlife, and participate in educational and interpretive activities (U.S. Fish and Wildlife Service, 1997a). As visitation increases, significant economic benefits are generated to local communities. On a national basis, refuge visitors contribute more than $400 million each year to local economies. Comprehensive Conservation Plan Tricolored Heron USFWS Photo by Evelyn McGraw. 4 A.R.M. Loxahatchee National Wildlife Refuge A.R.M. Loxahatchee National Wildlife Refuge History A.R.M. Loxahatchee National Wildlife Refuge, located 7 miles west of the city of Boynton Beach, is the only remnant of the northern Everglades in Palm Beach County, Florida (Figure 1). Unlike the name of many national wildlife refuges, Loxahatchee’s name was changed in 1986 to include a noted local conservationist Arthur R. Marshall. Most of the 147,392-acre refuge is encompassed by Water Conservation Area 1, which is owned by the State of Florida and is licensed to the Service. To the northwest of the refuge is the Everglades Agricultural Area which includes sugar cane farms, winter vegetable and sod farms, and cattle ranches. The land east of the refuge is predominantly urban with the exception of the agricultural lands of the East Coast Buffer area. To the south and southwest of the refuge lie Water Conservation Areas 2 and 3, and Everglades National Park--the only other remaining portions of the Everglades fresh water marsh. Beginning with the Swampland Act of 1845, and later the 1907 Everglades Drainage Act, excessive drainage activities occurred in the Everglades to pave the way for agriculture and development. To meet the ever-increasing water needs of agriculture and population expansion, three water storage areas called Water Conservation Areas 1, 2, and 3 (Figure 1), were constructed by the U.S. Army Corps of Engineers in the 1940s. Bounded by levees and connected by a series of canals, these areas were placed under the jurisdiction of what is now the South Florida Water Management District, an agency of the State of Florida. In 1951, a license agreement (Appendix N) between the South Florida Water Management District and the Service, under the Migratory Bird Conservation Act, enabled the establishment of the 143,238-acre Loxahatchee National Wildlife Refuge at Water Conservation Area 1. This “refuge interior” land, as it is called, is owned by the State of Florida, but managed by the Service. The license agreement was later amended to include the 1604-acre Strazzulla Marsh, which lies adjacent to Water Conservation Area 1 (Figure 2). In addition to the lands licensed from the District, the Fish and Wildlife Service owns 2,550 acres to the east and west of the refuge interior. This acreage is sub-divided into four management compartments--A, B, C, D, and the Cypress Swamp. In total, the refuge currently includes 147,392 acres of northern Everglades habitat. The refuge is currently managed by a staff of 20 permanent and 4 temporary/seasonal personnel. The permanent personnel include a project leader, deputy project leader, a refuge operation specialist, 2 Everglades Program Team members, 2 administrative staff, 3 law enforcement staff, 4 biological staff, 4 maintenance/operations staff, and 2 public use staff. In fiscal year 1999, the refuge operated with a budget of $1,451,000 for payroll and operation needs and received $357,000 in special funding authorized by Congress to address the maintenance backlog. For fiscal year 2000, the refuge was allocated $1,520,700 for payroll and operation needs and also received $144,100 for projects authorized by Congress. The refuge Headquarters Area is the main entrance for refuge administration, education, and public access. It contains an entrance fee booth, administration building, a visitor center, four permanent residences, the Everglades Program Team office building, a vehicle storage building, four sheds, and a maintenance complex. In addition to these administrative facilities, the area contains three boat ramps, a floating boat house, seven parking lots, a boardwalk, an observation tower, observation platform, and a fishing platform. The Hillsboro Recreation Area, located at the southernmost point on the refuge, contains a parking area and boat ramps. White ibis colony USFWS Photo by F. Broerman Comprehensive Conservation Plan Comprehensive Conservation Plan 5 Comprehensive Conservation Plan �� ���� �� Figure 1. Regional perspective for A.R.M. Loxahatchee National Wildlife Refuge 6 A.R.M. Loxahatchee National Wildlife Refuge ���� ��� ���� ���� ���� Figure 2. Boundaries and potential buffer lands at A.R.M. Loxahatchee National Wildlife Refuge Comprehensive Conservation Plan Comprehensive Conservation Plan 7 Purpose The Migratory Bird Conservation Act of February 18, 1929, 45 Stat. 1222, the Act of June 30, 1948, 62 Stat. 1171, 1176, authorizing the construction of the Central and Southern Florida Flood Control Project and the Fish and Wildlife Coordination Act of March 10, 1934, 48 Stat. 401, amended by the Act of August 14, 1946, 60 Stat. 1080, authorized the establishment of Loxahatchee National Wildlife Refuge on January 1, 1951. The refuge was created by two agreements entered into by the Department of the Interior. The first agreement is a General Plan with the Florida Game and Fresh Water Fish Commission (now the Florida Fish and Wildlife Conservation Commission) which permitted Water Conservation Area 1 to be used by the Fish and Wildlife Service for the national migratory bird management program. The second agreement is a long term License from the Central and Southern Florida Flood Control District (now the South Florida Water Management District) which provided for the use of Water Conservation Area 1 by the Service “as a Wildlife Management Area, to promote the conservation of wildlife, fish, and game, and for other purposes embodying the principles and objective of planned multiple land use.” According to the Fish and Wildlife Coordination Act, this refuge “...shall be administered by him (Secretary of the Interior) directly or in accordance with cooperative agreements... and in accordance with such rules and regulations for the conservation, maintenance, and management of wildlife, resources thereof, and its habitat thereon....” (16 USC § 664). The Migratory Bird Conservation Act of 1929 states that the refuge is to be “...for use as an inviolate sanctuary, or for any other management purpose, for migratory birds.” (16 USC. § 715d). This purpose and the mission of the National Wildlife Refuge System is fundamental to determining the compatibility of proposed uses of the refuge. The compatibility of these uses is discussed in Appendix D. Ecosystem and North American Context Role of Refuge in South Florida Ecosystem Plan: In response to the complexity of the South Florida and Everglades Ecosystems, a South Florida Ecosystem Plan was completed by the Service’s South Florida Ecosystem Team. This plan identified the goals, objectives, and strategies for this ecosystem and the major issues associated with eight ecosystem sub-regions. The refuge, located in the Florida Everglades ecosystem subregion (Figure 4), will make a significant contribution to achieving the objectives of this plan. Consistent with the South Florida Ecosystem Plan, the refuge will reduce exotic species; manage water quality and quantity through partnerships; inventory and monitor wildlife and habitat; enforce laws to protect refuge resources; promote public awareness about the ecosystem; provide wildlife-compatible recreation; and maintain facilities and equipment at or above Service standards. The Refuge Manager attends and participates in monthly working group meetings of the South Florida Ecosystem Team, which is comprised of Service field stations in an area from Ft. Myers to Vero Beach and south to the Keys. This team works together to accomplish Service priorities which include protection and management of federal trust species and combating the ever increasing problem of exotic invasives. During the past two years the refuge has taken an active role in partnership efforts to protect and enhance habitats and wildlife both on and off refuge. Staff members have participated on water preserve area study teams designed to provide buffer lands east of the Everglades that will provide short hydro-period wetlands, enable ground water recharge, and capture water for storage and delivery to east coast populations. Staff Comprehensive Conservation Plan 8 A.R.M. Loxahatchee National Wildlife Refuge ���� �� Figure 3. Upper Everglades Basin of importance to central Florida wintering waterfowl, breeding mottled ducks and wood ducks Comprehensive Conservation Plan Comprehensive Conservation Plan 9 Comprehensive Conservation Plan are also working closely with county and state efforts to provide wildlife corridors and greenways connecting several of the large land management areas. In addition, the refuge is an active participant in Palm-Net, a network of federal, state, and county agencies and private organizations working together to provide interpretation and environmental education opportunities to the public. Role of Refuge in Everglades Restoration: The refuge is an important part of the overall Everglades ecosystem. The refuge receives water flowing south from Lake Okeechobee (S5-A Pump Station) and the Everglades Agricultural Area (S6 Pump Station). Discussions of re-plumbing the Everglades have included decompartmentalization including removal of the levees surrounding the refuge. However, removing the western and southern levees would allow water to flow south to Water Conservation Areas 2,3 and Everglades National Park, but would result in less control over maintaining water in the northern part of the system. In addition, because of land subsidence north and west of the refuge, if the levees were removed, water would flow north and west instead of the historic southerly direction and drain the refuge. Model runs of decompartmentalization show a decrease in Lake Okeechobee levels and a decrease in overall water supply leading to the conclusion that at this time, removal of the levees would not be beneficial to water supply or ecological values of the system or to the refuge. However, as part of the restoration, agricultural drainage water that comes through the S6 Pump Station would soon stop and it will be re-routed through the new Stormwater Treatment Area 2, and into Water Conservation Area 2. The construction of canals throughout the Everglades ecosystem, as a whole, has changed historic sheet-flow patterns. Comparisons of newly shot aerial photos to historical aerial photos show elongate tree islands appear to be losing their overall appearance of a teardrop or a strand shape. Studies indicate that loss of a consistent north to south water flow over the refuge is one of the factors contributing to this landscape change (Brandt 2000). The refuge’s water regulation schedule, revised May 1995, has provided a mechanism to keep water levels in the refuge from dropping below 14 ft. NGVD. This schedule keeps the refuge from completely drying out every year. Though periodic dry outs are part of the natural cycle, yearly dry outs can reduce fish populations (prey for many species including wading birds), reduce the number of apple snails available for snail kites, provide additional areas for the germination and spread of exotic vegetation, and increase fire risks. Since the adoption of the regulation schedule in 1995, no major fires have occurred in the refuge, and the refuge experienced a record year for wading bird nesting in 1999. Stormwater Treatment Areas 1 East and 1 West will assist hydropatterns by providing a ready reservoir of low nutrient water that the refuge can draw from when needed. Water quality and water quantity issues will continue to be major concerns in the protection of the resource. Until there are assurances that water entering the refuge is clean, options that put more (greater than recent levels) dirty water into the refuge are not considered ecologically beneficial. The existing water regulation schedules appear to be benefitting the ecological system within the refuge. Protecting the resources in the refuge contributes to overall Everglades restoration in that it helps to maintain the spatial extent and heterogeneity of historic habitats. This will contribute to the overall maintenance of system biological diversity. The refuge is working cooperatively with the Corps of Engineers and South Florida Water Management District to better manage water resources in the context of multiple uses (needs for the environment, urban, and agricultural uses), including the use of long term forecasting and rainfall driven operations. Refuge personnel have, in the past and more recently, 10 A.R.M. Loxahatchee National Wildlife Refuge increased participation in discussions of restudy and restoration alternatives by participating in various committees and advisory groups including: Alternative Evaluation Team coordinated by the Corps of Engineers (disbanded 1999) Restoration Coordination and Verification and subteams (i.e., Adaptive Assessment Team, Regional Evaluation Team) coordinated by the Corps of Engineers Water Preserve Area Technical Oversight Committee Everglades Technical Advisory Committee Partners-In-Flight Program: Recent documentation of plummeting bird numbers, especially of migrant passerines (Hagen and Johnston 1989, Finch and Stengel 1992) stimulated the formation of Partners-In-Flight, an international organization to address the needs of non-game migratory birds. The Service is one member of the Partners-In-Flight Program that includes coordination between federal, state and non-governmental agencies, industry, and conservation groups to promote research, land protection, and education about migratory birds. The refuge is in the Atlantic Flyway, one of the primary migratory routes of bird species that breed in temperate North America and winter in the tropics of the Caribbean and South America. More than 116 species of neotropical migrants have been recorded passing through the south Florida ecosystem. More than 129 bird species migrate to the south Florida ecosystem to overwinter, and another 132 species breed in the ecosystem. Because this ecosystem is located near Cuba and the West Indies, it draws Caribbean species that rarely appear elsewhere in North America. In 1995, the Service prepared a list of migratory non-game birds of management concern in the United States to stimulate a coordinated effort by federal, state, and private agencies to develop and implement comprehensive and integrated approaches for the management of selected species (Tables 22 and 29). The south Florida ecosystem supports many of these species (Appendix L). Western Hemisphere Shorebird Reserve Network: The refuge is also an important stopover location for many species of migratory shorebirds and a nesting location for some shorebirds. Although the refuge is not designated as a strategic migrational site by the Western Hemisphere Shorebird Reserve Network, it does provide important foraging habitat for these species and contributes survey data to the network. North American Waterfowl Management Plan: Since the first settlers arrived, more than 50 percent of the United States’ original 220 million acres of wetlands, upon which waterfowl depend, have been destroyed often causing dramatic declines in numerous waterfowl populations. Although some populations have declined, waterfowl remain an economically important group of migratory birds on the North American continent. According to the 1996 National Survey of Fishing, Hunting and Wildlife Associated Recreation, approximately 1.8 million people spent $740 million annually to hunt ducks, both on and off national wildlife refuges. About 18.6 million people spent $2 billion observing, photographing, and otherwise appreciating waterfowl throughout the United States, not just on refuges (Fish and Wildlife Service, Division of Federal Aid). Recognizing the importance of waterfowl and wetlands to North America and the need for international cooperation to promote their well-being, the Canadian and United States governments developed a strategy to restore Comprehensive Conservation Plan Mottled Ducks USFWS Photo by B. Thomas, Jr Comprehensive Conservation Plan 11 waterfowl populations to the levels of the 1970s through habitat protection, restoration and enhancement. The strategy was documented in the North American Waterfowl Management Plan, which was signed in 1986 by the Canadian Minister of the Environment and the United States’ Secretary of the Interior. This plan identified important waterfowl habitat areas, established habitat and population goals, and established interstate/ international partnerships, called joint ventures, to implement plan goals. In 1997, the Atlantic Coast Joint Venture continued to build upon its firm foundation as Florida became its 17th state partner. Mid-winter data indicate that 17 to 26 percent of the Atlantic Flyway’s January censussed duck population winter in north and central Florida--an incidence greater than in any other state in the flyway. A small portion of the refuge lies within the Upper Everglades Basin, which provides winter waterfowl habitat for scaup, ring-necked ducks, redheads, blue- and green-winged teal, wigeon and fulvous-whistling ducks, which are the most abundant species of waterfowl wintering in all of Florida (Figure 3). It also provides breeding habitat for mottled and wood ducks. Thus, the refuge has the potential of providing habitat for a portion of the North American wintering population, especially for ring-necked ducks. Management activities contribute towards meeting numerous goals of the North American Waterfowl Management Plan. The issue of high mercury levels found in resident fish and alligator body burdens raises concerns about resident waterfowl. Population monitoring and heavy metal testing is needed for mottled and wood ducks including determining if a health advisory is needed regarding these locally harvested species. It is assumed that because they are not fish-eating birds the levels are within tolerance levels, however testing would be prudent. Legal Context In addition to the refuge’s authorizing legislation and the National Wildlife Refuge System Improvement Act of 1997, the legal and policy guidance for the operation of national wildlife refuges is contained in the documents or acts listed below. For a description of the key legislation and policies, see Appendix F. Executive Order 1312- Invasive Species (2/3/99) National Wildlife Refuge System Administration Act of 1966 (16 USC 668dd-668ee) Refuge Recreation Act of 1962 (16 USC 460k-460k-4) Title 50 of the Code of Federal Regulations, Subchapters B and C The Refuge Manual Fish and Wildlife Service Manual Endangered Species Act of 1973 (16 USC 1531-1543) Migratory Bird Hunting and Conservation Stamp Act (16 USC 718-718h) Migratory Bird Treaty Act of 1918 (16 USC 703-712) National Environmental Policy Act of 1969 (PL 91-190, 42 USC 4321-4347) Bald Eagle Protection Act of 1940 (16 USC 668-668d) American Indian Religious Freedom Act (P.L. 95-341, [1978], 92 Stat. 42 USC 1996) Antiquities Act (P.L. 59-209, approved 6/8/1906, 34 Stat. 225, 16 USC 431-433) Archaeological Resources Protection Act (P.L. 96-95 [10/31/1979], as amended by P.L. 100-555 [10/18/1988] and P.L. 100-588 [11/3/1988], 93 Stat. 721, 16 USC 470 aa et seq.) Archaeological and Historic Preservation Act (P.L. 93-291 [1974, 88 Stat. 1974], amending Reservoir Salvage Act, 16 USC 469) Executive Order 13007 - Sacred Sites (5/24/1996) National Historic Preservation Act (P.L. 89-665 [1966], 80 Stat. 95, as amended by P.L. 96-515 [1980], 94 Stat. 2987; P.O. 102-575 Title 40 (1992), 106 Stat. 4600) Native American Grave Protection and Repatriation Act (P.L. 101-601 (1990), 104 Stat. 3048, 25 USC 3000-3013, 18 USC 1170) Comprehensive Conservation Plan 12 A.R.M. Loxahatchee National Wildlife Refuge ��� ���� ��� Figure 4. Florida Everglades Ecosystem Subregion* within the South Florida Ecosystem Comprehensive Conservation Plan Comprehensive Conservation Plan 13 II. Planning Issues and Opportunities Introduction Early in the development of this plan, the planning team developed a list of issues and concerns that was likely to be associated with the management of the refuge. This list was derived from team knowledge of the area, a public scoping meeting, and written comments submitted by the public. The scoping meeting, held on August 17, 1998, provided the public with an opportunity to identify issues and concerns. Approximately 60 persons attended the meeting. After a 15-minute presentation on the values of the refuge, the meeting participants were divided into small groups, with the group discussions facilitated by a consultant and planning team members. The comments of each group, following a structured format, were recorded on flip charts. These comments are summarized in Appendix G. Responses from comment sheets, distributed at the scoping meeting and at the refuge, and handwritten letters or postcards also provided information on issues and concerns of importance to the public. The comment packet and a summary of the comments are found in Appendix H and I, respectively. Using the above sources, the planning team developed an abbreviated list of statements reflecting major issues and concerns. While the summary statements, presented below, may not be identical to the original statements given by the public, the statements accurately reflect the intended meaning of the comments received. The responsiveness of the alternatives to these issues and concerns is summarized in Appendix A, Table 18. Summary Statements Wildlife Habitat Management The increasing number of exotic and invasive plant and animal species is negatively impacting the refuge’s native wildlife and habitat. Many local citizens were concerned about the threat exotic plants and animals pose to the ecosystem and to the water supply. The public mentioned such threats as melaleuca, Old World climbing fern, Brazilian pepper, Australian pine, walking catfish, armored catfish, the bromeliad weevil, and the Asian fresh-water marsh eel. It is their desire that the refuge staff increase its efforts to protect native plants and wildlife from these threats. There is a need to improve the management of species and habitats to enhance the native biodiversity and integrity of the refuge. Many citizens stated that it is imperative that the refuge manage the remaining portion of the Everglades to improve habitats and wildlife populations. Some people believe that past refuge administration allowed wildlife and habitats to decline and they wish that the land had been better managed. Many people expressed frustration at the poor condition of the impoundments and wondered why there was not more wildlife available to observe on a year-round basis. The degraded water quality and past water management practices (e.g., water quantities and schedules) are negatively impacting the refuge’s ecosystem. Many people stated the need for better water quality and an adequate water quantity for the refuge. Other people, however, expressed concern about having sufficient water for agriculture and the urban areas, particularly if the refuge takes what it needs. Comprehensive Conservation Plan Boat-tailed grackle USFWS Photo by Evelyn McGraw 14 A.R.M. Loxahatchee National Wildlife Refuge Refuge Protection The refuge is threatened by rapid development of residences, planned communities, strip malls, or golf courses near its boundaries. Many people recognize the threat of impending development and its impact on the natural land base in the south Florida region, and they wish to protect lands around the refuge from development. Some people would like to see the current agricultural land use adjoining the refuge perpetuated or more land set aside for natural areas. Many people appeared to understand the fragility of the Everglades ecosystem and support restoring adjacent lands to a native state. The wildlife and habitats are not protected enough. Many comments were written supporting greater protection of refuge wildlife and habitats, especially for threatened and endangered species. Many people expressed a desire to see the whole biological system protected. Others believe that providing protection to wildlife and habitat is especially important even if it means limiting public access. Public Use There are not enough opportunities to observe wildlife and its habitat in a quiet, natural, non-developed environment. Many people expressed their appreciation for the refuge, its relatively quiet environment and its undeveloped nature. Since much of the land in south Florida has been developed (in their view), the refuge needs to stay relatively unsullied and quiet--a sanctuary for the public as well as for wildlife. Some people wished that more areas of the refuge (e.g., Strazzulla Marsh or the perimeter levee) were open so they could participate in more passive wildlife observation. Many people said that they don’t want any activity that will disrupt wildlife populations or damage wildlife habitat. There is a need for increased access to the refuge for active recreational uses such as hiking, camping, bicycling, horseback riding, canoeing and airboating. A number of people would like to bicycle, horseback ride, ride all-terrain vehicles, camp, hike, or airboat on the refuge. Many people believe that many kinds of recreation have not been offered to the public and should be. Due to the loss of natural lands in south Florida, people said they want to be able to enjoy green space in ways other than walking. There is a need to provide increased access to the refuge for hunting waterfowl, deer, alligator, turkey, bear and frogs. The habitat needs better management for fishing and hunting activities. Some people expressed frustration that the refuge provides a limited amount of access for hunting; further, they wished that the refuge allowed the use of airboats, especially for that purpose. Others desired a greater number of species to hunt. A number of individuals expressed frustration with what they perceive to be poor management of hunting and fishing habitat, especially with regard to the dense cattail growth at the south end of the refuge. Don’t allow airboating. A number of people wrote comments and stated at the public meeting that the refuge should not be opened to private airboating. Comprehensive Conservation Plan Comprehensive Conservation Plan 15 There is a need to provide access and improve/provide public use facilities at the Hillsboro Recreation Area and at Strazzulla Marsh. Many people expressed a desire for improved facilities and support services at the Hillsboro area, located at the south end of the refuge. The desired facilities and services should include a concession (with interpretive tours, boat rentals, educational experiences), usable boat ramps, telephones and restrooms. In addition, some people wished to have access to Strazzulla Marsh. Many people were concerned about the poor maintenance of the canoe trail and lack of additional access to the refuge interior. A few people desired an access point at the north end of the refuge to replace the closed “20-Mile Bend” access point. There is a need to expand environmental education and interpretation, highlighting the Everglades ecosystem. Many people want to experience a greater number and variety of environmental education programs on the refuge. Further, they want their children to learn about the Everglades through the refuge. Some people said that new exhibits are needed, which can be rotated, and that facilities needed to be upgraded. Some citizens wished that the refuge would provide more educational tours for school and senior citizen groups, and summer camps. Partnerships There is a need for the refuge to develop partnerships with state, county and community agencies, universities and educational institutions, natural resource based organizations and other entities. People think the refuge should work more closely with other natural resource agencies and user groups. To enhance management, some people believe there is a need to share equipment and knowledge between agencies. Take the refuge from the Fish and Wildlife Service and give it back to the State (Florida Fish and Wildlife Conservation Commission). Some people do not want the Service to manage Water Conservation Area 1. Currently, a license agreement with the South Florida Water Management District gives authority to the Service to manage wildlife in keeping with its mission and establishing legislation, but the Water Management District retains the authority to manage water for flood control and water supply. These citizens feel the Agreement has been violated regarding wildlife and habitat management and by public access. Many of the public wish the refuge to develop ecotourism connections with the business community. Citizens recognize that the refuge is a tourist attraction and they hope that it can continue to be beneficial to the local economy. Some citizens wish the refuge would join the Chamber of Commerce and create connections between hotels, recreational sport organizations and businesses. Comprehensive Conservation Plan 16 A.R.M. Loxahatchee National Wildlife Refuge Significant Resource Problems Water quality, quantity and timing, invasive and exotic plants and animals, and urban growth are three major factors affecting the welfare of fish, wildlife, and plants on the refuge and the surrounding ecosystem. The defining element of the refuge and the whole of the Everglades is water, its quality, delivery timing and amount. This unique ecosystem has had a very low nutrient base for thousands of years and is comprised of species that have evolved to thrive under low nutrient conditions. Human activities adjacent to the refuge have introduced nutrients, primarily fertilizers, which enhance the growth of many non-indigenous and invasive species to the detriment of native species. Increased nutrients change bacteria and algae, the most basic level of the system. This moves through the system until it is visible as the vast unnatural acreages of cattail. Replacing the natural Everglades marsh vegetation, these nuisance species create monotypic stands that are far less productive for wildlife and lacks the visual appeal of a diverse natural Everglades. The reduction of nutrients entering the refuge has been and will continue to be a major issue. The Everglades Nutrient Removal Project was completed in October 1993 (South Florida Water Management District 1997). This serves three primary purposes: (1) to reduce phosphorus loads entering the refuge and help minimize imbalances in Everglades flora and fauna; (2) to develop the design, construction, operations, and maintenance experience necessary for large scale application of flow-way treatment technology; and (3) to implement optimal nutrient removal technology. Currently the Everglades Nutrient Removal Project is in the last stages of conversion to Stormwater Treatment Area 1-W. Stormwater Treatment Area 1-E, through which surficial water will also be filtered, will be built adjacent to the northeast portion of the refuge. The Everglades Nutrient Removal Project, combined with best management farming practices, has already achieved phosphorous levels below the original goal of 50 PPB. However, a numeric standard still needs to be set for the amount of phosphorus that no longer causes an imbalance to flora and fauna. To reach this standard will require design and implementation of new technology. The standard will not only provide a basis for assessing the financial resources required to achieve water quality, but also a basis for monitoring. Because the Everglades is no longer a free-flowing system that relies on temporal weather patterns to sustain it, humans must now attempt to provide water when and where the system can most benefit. The system evolved under variation, not constant annual schedules. Unfortunately, the water delivery system in place often exhibits its inadequacies in the form of extended droughts or floods. Technology must be developed and implemented to allow water managers to be more responsive to the natural system’s needs and still meet the demands for water supply and flood control. Comprehensive Conservation Plan Melaleuca USFWS photo by M.D. Mattei Comprehensive Conservation Plan 17 Exotic plants and animals are a tremendous threat to the ecosystem and to its water supply. The refuge has the worst invasive exotic plant problem in all of south Florida, and among the worst in National Wildlife Refuge System, with more than 96,000 acres infested to varying degrees. The amount of funding needed to control exotic plants is great, especially considering the insufficient funding nationwide for national wildlife refuges. A greater awareness is needed to maintain the refuge’s biological integrity (See Refuge Environment, Exotic Plants). Species such as melaleuca, Old World climbing fern, Brazilian pepper, Australian pine, walking catfish, and now the South American armored catfish, bromeliad weevil, and Asian fresh-water marsh eel are threats that are currently visible. New “exotics” will undoubtedly appear as the refuge struggles to find controls for established species. Exotics are not just costly threats to the natural environment, but also to agriculture, land development, business, and human health as well. To meet the demands of a growing urban population, there is a continuous stream of land use proposals for lands surrounding the refuge. These proposed land use changes are often detrimental to the natural environment and the aesthetics of the area. For example, power transmission lines and high speed rail have been proposed to extend through the refuge natural and public use areas. Solid waste disposal sites have been proposed to abut the refuge boundary, which will bring unsightly mountains of waste adjacent to public use areas and adversely affect wildlife and water quality. However, the most likely immediate threat is from the rapidly escalating speed with which strip malls and housing developments are being built, especially adjacent to the refuge borders. Comprehensive Conservation Plan 18 A.R.M. Loxahatchee National Wildlife Refuge Comprehensive Conservation Plan 19 III. Refuge Environment Physical Environment Climate Located in the subtropical region of south Florida, the refuge’s climate is hot and humid most of the year and the winters are mild. In general, there are two seasons--wet and dry. The wet season occurs from late May to late October. The refuge receives some of the highest amounts of rainfall in south Florida (Gleason et al., 1975). While annual rainfall ranges from 40 to 83 inches, about 60 inches is typical. More than one-half of the rainfall for the year occurs between June and September in the form of thunderstorms. Only one hurricane (Irene in 1999) has made a direct hit on the refuge since it was established, however, numerous hurricanes and tropical storms have skirted it, and these have caused large rainfall events primarily during the months of August to November. During the dry season, November to May, rain falls during the cold fronts which average about seven per month from December through March, but the amount is significantly less than during the wet season. Winds prevail out of the southeast and the average relative humidity is 75 percent. While air temperatures at the refuge have ranged from 20°F to 101°F, the mean summer temperature and the mean winter temperature are 89°F and 56°F, respectively. The combination of humidity and temperature causes heat indices to range from 105°-110°F in the summer. Since the eastern edge of the refuge is located within 12 miles of the Atlantic Ocean, temperatures are moderated. The temperatures also are moderated by the surface water of the Everglades. Physiography, Soils, and Geology The refuge is composed of 147,392 acres of Everglades habitat. The refuge is part of a large fresh water storage area connected by a series of canals and levees, which were completed by the Corps of Engineers in 1960. The underlying aquifer provides water into nearby coastal communities. Underlying the refuge is a depression in the Fort Thompson Formation, a limestone bedrock, which results in greater water depth than the surrounding Everglades. Unlike other areas of the Everglades, where there are only shallow layers of soil overlying the bedrock, soil depths in the refuge range from 3.6 - 14.0 feet (Silveira 1996). The soil is primarily Loxahatchee Peat which forms from the roots, rootlets, and rhizomes of white water lily, and is an indication of a historic slough community. The peat is lightly colored, fibrous and spongy, reflective of high organic content. The low ash content of the soil is an indication of infrequent burns in the area. Loxahatchee Peat is found only in two areas in the Everglades--in the refuge and Water Conservation Area 2, and in the western portions of Water Conservation Area 3 and Shark Slough. Loxahatchee Peat is slightly more acidic and has lower mineral content than other peats. The oldest peat on the refuge has been dated at 4,800 years. Everglades Peat (formed primarily from sawgrass) and Gandy Peat (formed from woody material, especially associated with tree islands) also are present on the refuge. Comprehensive Conservation Plan USFWS Photo by S.D. Jewell 20 A.R.M. Loxahatchee National Wildlife Refuge The refuge is on a gradual north to south slope which results in slowly moving surface water sheet flow. The topography undulates throughout the refuge, creating mounds and depressions that are covered by varying depths of water. In addition, the refuge contains thousands of tree islands which form when a layer of peat dislodges itself from the substrate and floats to the surface. During periods of low water, tree islands become rooted to the substrate. Plant succession occurs rapidly, and within about three years, woody vegetation is established. Hydroperiod and Hydropattern Water flowing from the Everglades is vital to supplying surface water for south Florida, replenishing the Florida and Biscayne aquifers, carrying essential nutrients and clean, fresh water to estuaries, and supporting an extremely rich and diverse assemblage of wildlife and plants. Changes in the hydroperiods (the duration that an area is inundated) and hydropatterns (the depth, timing, flow, and location of surface water) have altered these vital wetland functions in the south Florida ecosystem. Historically, surface water originating from rainfall and natural springs flowed from the Kissimmee basin of central Florida. The spring fed creeks formed rivers and filled Lake Okeechobee. From that point, water overflowed the south end of the lake and began its southward sheet flow to the southern tip of Florida. Historically, the precipitation that fell on the Everglades could spread out over the entire area (>2,317 square miles). To prevent flooding and provide agricultural and developmental land use, the Corps of Engineers started the massive and historic effort of controlling Everglades waters through construction of hundreds of miles of levees and canals. This construction has not only constricted sheet flow, but also has removed excess” Everglades water to the ocean. As the levees and canals were completed, water ceased its natural flow through the Everglades; rather, it was channeled through what is now the refuge. In contrast to the past, water now enters the refuge from rainfall and three access points of controlled surface flow. Construction of the levees has had significant effects on the hydrology, vegetation, and wildlife in the refuge. The shallow shorter hydroperiod marshes that once surrounded the refuge have been replaced by deep-water habitats along the canals. Lost is the mosaic of habitats that provided, in the same year, the availability of deeper water slough habitats for foraging snail kites and shallower marshes for foraging wading birds (e.g., wood storks). Changes in the natural timing of water levels affect wading bird feeding patterns, apple snail reproductive output, and alligator nesting. In addition, changes in the patterns of water depth have resulted in changes in aquatic vegetation and tree islands. In areas that have become wetter, particularly along the rim canal, tree islands have decreased in size and number (Brandt 2000), and more aquatic communities have developed (Hagenbuck et al., 1974). In drier areas, particularly the northern portion of the refuge, woody vegetation has become more abundant (Hagenbuck et al., 1974). Lower water levels, particularly during the dry season, increase the potential for fire and for fires to burn hotter, resulting in more damage to vegetation and soils. Another consequence of impoundment has been the reduction of water flow through the refuge. A reduction in flow rates has changed the patterns of nutrient transport, seed dispersal, soil accretion, or loss. Brandt(2000) provided some evidence that changes in flow as well as hydroperiods and depths have contributed to the changes in the patterns of tree islands in the refuge. The importance of flow as a structuring process, as well as hydroperiods, should be considered for the maintenance of the ecological integrity of the refuge and the Everglades. Comprehensive Conservation Plan Comprehensive Conservation Plan 21 Timing and volume of water releases from the refuge also have influenced lands and waterways east and south of the refuge. By sending water to the eastern urban areas, water flowing southward through the Everglades ecosystem is greatly reduced, resulting in increased salinity in Florida and Biscayne Bays. Prior to June, in preparation for the hurricane season, the Corps of Engineers releases a large volume of fresh water from the refuge into the Atlantic Ocean. This heavy pulse of fresh water into the nearby Atlantic Ocean dilutes the saline environment, creating negative affects on fish and marine life. Because this water is released near the refuge, the water cannot complete its historical sheet flow to the tip of south Florida. The loss of fresh water to Florida Bay has created hyper-saline conditions, which have negatively impacted the estuarine and bay production and the entire fishing industry. Overview of Water Regulation Purpose: A.R.M. Loxahatchee National Wildlife Refuge, also known as Water Conservation Area 1, is part of the Corps of Engineers’ Central and Southern Florida Project for Flood Control and other purposes (Figure 5). Water levels in Water Conservation Area 1 are regulated by a schedule to produce optimum benefits among competing interests. These interests are flood control, water supply (agricultural, municipal, and industrial), fish and wildlife enhancement, prevention of saltwater intrusion, and water supply to Water Conservation Areas 2 and 3 and Everglades National Park. To produce these benefits, the water level (elevation) in the refuge is adjusted as the year progresses, either by a release of water from Water Conservation Area 1, an intake of water from Lake Okeechobee, or by a combination of water release and intake. Water Intake: The current major sources of water for the refuge are rainfall (56 percent), the S-5A, G-251, G-310, and S-6 pump stations (40 percent), and ACME 1 and 2 pump stations (4 percent). These stations are located at the north, west and east sides of the refuge (Figure 6). The S-5A station pumps water from the West Palm Beach Canal; the G-251 and G-310 stations pump water from the Stormwater Treatment Area 1-W; the S-6 station currently pumps water to the Hillsboro Canal, but will soon be diverting all of this water into STA-2; and the ACME 1 and 2 pump stations discharge water from Basin B in the Village of Wellington area. The amount of water that comes in from S-6 is approximately 155,000-acre feet per year of water or 30 percent of the water that comes in through structures. This water loss will be made up by increased flows through the S-5A station and Stormwater Treatment Area 1-E and/or reduction in outflows from the refuge. Without this compensation the refuge will be greatly impacted. Occasionally, the refuge receives water by gravity from S-5A(S), a two-bay gated spillway. Of all the water coming into the refuge, 44 percent is artificially pumped and the remaining 56 percent is natural rainfall. Approximately 91 percent of the pumped water is drained from agricultural lands north and west of the refuge, while the remainder, 9 percent, is from agricultural and developed lands located east of the refuge through the ACME Stations (Figure 6). The pumping stations remove an average of 3/4 of an inch of agricultural area runoff per day from their respective drainage areas in the Everglades Agricultural Area. Comprehensive Conservation Plan 22 A.R.M. Loxahatchee National Wildlife Refuge ���� ���� �� �� �� Figure 5. Major canals of the Central and South Florida Project which affect water flow in and out of A.R.M. Loxahatchee National Wildlife Refuge and the rest of the Everglades Ecosystem Comprehensive Conservation Plan Comprehensive Conservation Plan 23 ���� ��� �� ���� ��� ���� Figure 6. The location of pump stations and spillways at A.R.M. Loxahatchee National Wildlife Refuge Comprehensive Conservation Plan 24 A.R.M. Loxahatchee National Wildlife Refuge Water Release: Water outlets from the refuge are the Lake Worth Drainage District and ACME Stations on the east side of the refuge and the S-10 and S-39 spillways on the west side. Serving as a flood control gate, the S-10 consists of three spillways--S-10A, S-10C, and S-10D. In addition, the South Florida Water Management District operates S-10E, which consists of three 6-foot diameter gated culverts, as an additional outlet from Water Conservation Area 1 into Area 2A. The primary purpose of the S-39 spillway is to make releases from the refuge to supply water needs to the Hillsboro Canal during the dry season. It also can be used to discharge excess water to the ocean when capacity is available in the Hillsboro Canal and when the water is not needed in Water Conservation Area 2 or 3. Water may also be released from the refuge through S-5A north for irrigation in the Everglades Agricultural Area when stages in canals in the C-51, L-10, L-12 or L-8 basins are low. It is important to point out that both pumping in or release of water at a maximum volume is usually detrimental to breeding wildlife populations. Rapid changes in water depths do not allow some types of animals to reproduce successfully. For example, the primary food source for the endangered Everglades snail kite is the apple snail. This invertebrate crawls out of the water and lays eggs on herbaceous plant stems. If water rapidly rises, the eggs are submerged and they die. Thus a season’s worth of food supply will be lost for limpkins, alligators and other wildlife including the Everglades snail kite. If water levels fall too rapidly, fish populations may not be able to find sloughs or deeper water areas. The fish get stranded and die; a major component of the marsh food web is reduced and large populations of wildlife have insufficient food supplies. Refuge Water Regulation Schedule As indicated earlier, the water level in Water Conservation Area 1 is regulated to produce maximum benefits among the various interests–flood control, water supply, fish and wildlife, and prevention of salt water intrusion. To produce these benefits, the water level in the refuge is adjusted as the year progresses, either by a release of water from Water Conservation Area 1, an intake of water from Lake Okeechobee, or by a combination of water release and intake. The particular action taken to release, intake, or retain water is dependent upon the water elevation in a given month. Water elevations, grouped into four zones--A1 (Flood Control); A2, B (Water Supply); and C (Inactive) across time, comprise the water regulation schedule (Figure 7). Zone A1 is the flood control zone from January through June. When water levels enter this zone, active water releases will be made due to flood conditions. If, for example, the water level reached 17.5 feet in January, water would be released through the S-10 spillway to achieve an elevation of 17.2 feet or lower. From July through December, attempts are made to maintain water levels within Zone A2. In this zone, water levels in Water Conservation Area 1, which are linked with rainfall amounts and the water level at Lake Okeechobee, are permitted to reach a maximum of 17.5 feet; “excess” water Comprehensive Conservation Plan Water management at Compartment D USFWS Photo by B. Thomas Jr. Comprehensive Conservation Plan 25 Comprehensive Conservation Plan �� ���� ��� Figure 7. Water regulation schedule for Water Conservation Area 1, A.R.M. Loxaxatchee National Wildlife Refuge1 is released from the S-10 and S-39 spillways. When additional water is needed for Water Conservation Area 2A or other areas, it is released from Area 1, depending on relative water level at Lake Okeechobee. Zone B, the water supply zone, ranges from a minimum of 14.0 to 17.5 feet during the year. This is the zone targeted to be most beneficial to fish and wildlife on the refuge. When Area 1 water levels are within this zone, water supply releases are made from Area 1 as needed, in relation to the water level at Lake Okeechobee. For Zone C, when water levels drop to 14.0 feet or less, there would be no net release of water from Area 1. Any water supply releases would be preceded by an equivalent volume of inflow from the lake. There have been temporary deviations from the regulation schedule during excessive rainfall events that occurred in 1995, during the El Niño event that occurred during the dry season, January through mid-May 1998, and after Hurricane Irene in the fall of 1999. This allowed water to be stored in Water Conservation Area 1, as well as A2. Benefits of Water Regulation Schedule: The refuge water regulation schedule is designed to generate the following benefits to fish and wildlife and their habitats: Increased water depth during the wet years in the northern portion of the refuge; Increased hydroperiod of interior marshes to avoid annual dryout; Increased area of interior marsh which serves as nursery areas for aquatic organisms; Improvement in timing of winter stage drawdown to benefit wading birds; Restoration of deep water habitats suitable for nesting Everglades snail kites; Greater water storage within the central and southern Florida project system during wet and normal rainfall years; 26 A.R.M. Loxahatchee National Wildlife Refuge Water Quality Due to human activities during the last century, nutrients and toxic substances are ubiquitous and an ever-increasing problem in the south Florida environment. Nutrients and toxic substances from urban and agricultural lands have degraded the relatively pristine lakes, streams, estuaries, and bays of the region (McPherson and Halley 1997). Nutrients: Impacts on the Everglades Fertilizers are widely used in south Florida to maintain high levels of agricultural productivity. From July 1990 through June 1991, fertilizers sold in south Florida contained 140,000 tons of inorganic nitrogen and 56,000 tons of phosphate (McPherson and Halley 1997). Nutrient loading from urban areas and the Everglades Agricultural Area has significantly increased nutrient concentrations, particularly phosphorus, in the water conservation areas (Stober et al., 1996). Historically, the Everglades has been deficient in nutrients with phosphorus concentrations averaging 10 parts per billion (Lodge 1994); if phosphorus exceeds 50 parts per billion in the water conservation areas, there is a good chance that eutrophrophication will occur. Researchers have documented a variety of negative effects from increased nutrients such as increased soil phosphorus content; changed periphyton communities; loss of native sawgrass communities; increased organic matter in water; reduced dissolved oxygen; conversion of wet prairie plant communities to cattails; and loss of important habitats for wading birds (Stober et al., 1996). As indicated earlier, approximately 91 percent of the water pumped into the refuge is drained from agricultural lands and developed lands east of the refuge. High nutrient runoff (specifically phosphorus) from agricultural lands is one of the most serious issues facing the refuge; this runoff causes proliferation of cattails and other undesirable plant species that negatively affect the ecosystem’s balance. Areas in the western, southwestern, southern, and southeastern portions of the refuge continue to be eutrophied by the influx of nutrients (Fish and Wildlife Service 1996a). The refuge is unique in that most of the high nutrient water received remains in the canals which surround the conservation area, instead of flowing directly through the refuge itself. Some high nutrient water does move into the refuge, but evidence indicates that it moves slowly and affects only a limited distance of Everglades habitat near the canals (McCormick, 1999). Much of the interior refuge water comes from rainfall. Portions of Water Conservation Areas 2 and 3, and even Everglades National Park, have been directly impacted through runoff entering into the central portions of these areas. The refuge’s water quality contrasts sharply with other Everglades habitats. Using data from the Everglades Consolidated Report, the refuge water quality differs (is lower) considerably from Water Conservation Area 2 with regard to the following: alkalinity ( by a factor of 5), specific conductivity (by a factor of 5), ammonia (by 63 percent), nitrate (by more than 50 percent), calcium (by a factor of 5), magnesium (by a factor of 6), sodium (by 478 percent), sulfate (by a factor of 16), chloride (by a factor of 5), and dissolved organic carbon (by 200 percent). However, the refuge has more than twice the amount of iron as Water Conservation Area 2, and this was listed as a concern in the report. Comprehensive Conservation Plan Comprehensive Conservation Plan 27 Comparison of phosphorus and nitrogen loadings (metric tons) as a percentage from water years 1990-1999 (South Florida Water Management District 2000). Area Mean Phosphorus Load Mean Nitrogen Load Refuge 35 % 28 % Water Conservation Area 2 23 % 21 % Water Conservation Area 3 37 % 33 % Everglades National Park 5 % 18 % When comparing the sizes of the refuge with Water Conservation Area 3 and the Everglades National Park, the refuge takes in much more phosphorus and nitrogen per acre. Extensive cattail marshes are associated with chemical and hydrologic imbalances derived from agriculture, or other impacted runoff waters (Gleason et al., 1975). While cattails are not described in historical accounts, or identified on early maps of the Everglades, cattails currently occupy at least 6,000 acres of the refuge (Richardson et al., 1990); they are also a persistent noxious weed in compartments, impoundments, and borrow canals. The water used to regulate these areas originates from the L-40 canal and is nutrient-rich, thereby contributing to the spread of cattail. Thick stands of cattail obstruct wildlife use of these wetlands and preclude wildlife-dependent recreation such as birding and photography. Legal Action In view of the adverse effects of nutrients on the Everglades, in 1988 the U.S. Attorney for South Florida filed a lawsuit on behalf of the refuge and Everglades National Park. The suit alleged that the State of Florida, by neglecting to enforce its water quality standards, allowed high nutrient runoff to enter Class III waters. In 1991, the State of Florida and the Federal Government signed a Settlement Agreement which mandated the development of a constructed wetland Everglades Nutrient Removal project and six stormwater treatment areas to filter nutrient-rich water, the application of Best Management Practices by farmers to reduce the amount of nutrients originating from their lands, and the research and development of supplemental technologies to enable water to meet the Class III standard. As indicated earlier, historic phosphorous loading in the northern Everglades is believed to have averaged about 10 parts per billion over time. To attain interim and long-term phosphorus targets, the South Florida Water Management District constructed in 1994, as a test method of removing phosphorous loads, a 3,700-acre wetland known as the Everglades Nutrient Removal Project. This project achieved its performance objectives based on 57 months of operational data (August 94-April 99) All 12-month rolling, flow weighted total phosphorus concentrations at the outflow were well below 50 PPB (Chimney et al., 2000) This project makes an important contribution toward water quality and the stormwater treatment areas are based on this project. Thus far, two of the six stormwater treatment areas have been completed. The Everglades Nutrient Removal Project is being incorporated into the footprint of a larger Stormwater Treatment Area (1W) for a total treatment area of 6,700 acres. Stormwater Treatment Area 1E, being constructed by the Corps of Engineers, will be 5,350 acres. Together, the stormwater treatment areas will straddle the north end of the refuge filtering water being pumped from the S5A station. These two filtering marshes, along with agricultural best management practices, will reduce phosphorous values to an interim value less than 50 PPB. Long-term values to be set by the Florida Environmental Regulatory Commission will be accomplished through a combination of Best Management Practices, optimization of the stormwater treatment areas, and appropriate new technologies. The successful construction, maintenance, and operation of stormwater treatment areas will be critical to ensuring water quality and quantity to the refuge. Comprehensive Conservation Plan 28 A.R.M. Loxahatchee National Wildlife Refuge Comprehensive Conservation Plan Toxic Materials: Pesticides and Herbicides Pesticides have been widely used in south Florida’s agricultural and urban areas to control insects, fungi, and other undesirable organisms. Since Florida has year-round warm temperatures and a moist climate, vigorous pest control is a necessity. Pesticide use per acre is ranked among the top five in the nation; at the same time, agricultural production only ranks 30th in the nation. Pesticides vary in their toxicity, transport, and persistence. While persistent pesticides (e.g., DDT, chlordane, dieldrin, and aldrin) have been banned from Florida, their residues often become widely distributed and are potentially hazardous to non-target biota (McPherson and Halley 1997). By far the most frequently detected insecticides in both surface waters and bottom sediments are the chlorinated hydrocarbons (Shahane 1994). Since the late 1960s, persistent organochlorine pesticides have been detected in fish, which are part of the Everglades food chain (Kolipinski and Higer 1969, McPherson 1973, Haag and McPherson 1997). Chlorinated chemicals, such as polychlorinated biphenyls, dioxins, and furans, which are used primarily in urban and industrial areas, pose a serious threat not only to fish and wildlife but also to human populations (Colborn et al., 1993). Although most uses of polychlorinated biphenyls have been banned since the late 1970s, these persistent chemicals are still found in the environment. In recent years, many organochlorine pesticides and polychlorinated biphenyls have been linked to hormone disruption and reproductive problems in aquatic invertebrates, fishes, birds, and mammals (Colborn et al., 1993). Herbicides, including atrazine, bromocil, simazine, 2-4-D, ametryn, hexazinone, and diuron, which have the highest rate of application, are among the most frequently detected herbicides in Florida’s surface waters (Shahane 1994). While the refuge shares the same challenges regarding some pesticides with other Water Conservation Areas and Everglades National Park, those pesticides of potential concern mainly for the refuge include endosulfan, diurnon, endosulfan sulfate, and 2, 4-D. Three metals of concern for the refuge include beryllium, iron, and mercury. Mercury Evidence of mercury contamination in fish and wildlife in south Florida fresh water ecosystems is extensive. High mercury levels have been detected in the endangered wood stork and other birds (Sundlof et al., 1994). Scientists suspect that increased mercury exposure may partially explain the 50-year decline in wading bird numbers. Fish and alligators sampled in the Everglades have high mercury levels in their tissues (Ware et al., 1990, Eisler 1987). In 1989, after discovering the extent and severity of mercury in fish, the Florida State Health Officer advised fishermen to avoid consumption of several species of fish in more than 1,000,000 acres of the Everglades. The health advisory for the refuge is as follows: “The Florida Department of Health and Rehabilitative Services has issued a health advisory urging limited consumption of largemouth bass and warmouth caught in certain portions of the Everglades due to excessive accumulation of the element mercury. Fish caught in Water Conservation Area 1 should not be eaten more than once per week by adults and not more than once per month by children under 15 and pregnant women, and fish caught in Water Conservation Areas 2 and 3 should not be eaten at all.” Air Quality Air quality is not perceived to be as critical a concern as water quality. However, research shows that some of the mercury in the Everglades, generated from incinerators or power plants, is transported there atmospherically. Comprehensive Conservation Plan 29 Comprehensive Conservation Plan Biological Environment Native Vegetation Vegetative Communities The native vegetative communities of the Everglades ecosystem found on the refuge include sloughs, wet prairies, sawgrass, tree islands, cattail, and Cypress swamp. Based on 1989 satellite imagery for the refuge interior, these communities have been grouped into four groups, namely, marsh, shrubs, tree islands, and cattail (Figure 8). These communities evolved in a watery system that naturally had low nutrients. Numerous algae species or periphyton growing on the submerged vegetation are the basis for all aquatic life, providing food for a host of micro and macro invertebrates and grazing fish species (Lodge 1994). Sloughs Sloughs are the deepest natural marsh communities in the Everglades. During the rainy season, water depth in sloughs may exceed 3 feet, with the annual average depth about 1 foot. The dominant vegetation includes white water lily, floating heart, and spatterdock (Lodge 1994). Submergent plants such as bladderwort, fanwort or chara are abundant (Fish and Wildlife Service 1997c). Underlying sloughs is peat soil, which support fish species and aquatic invertebrates. Wet Prairies In contrast to sloughs, wet prairies have shallower water levels and are characterized by short emergent plants such as beakrushes, spike rushes and red-root (Chapman, pers. comm.). Wet prairies are the most prevalent vegetative community (approximately 50 percent land coverage) in much of the central and eastern portions of the refuge, and are generally found between sawgrass marshes and sloughs. This important vegetative community provides prey for wading birds and the Everglades snail kite in the form of fish, aquatic invertebrates and apple snails (Lodge 1994). Sawgrass The sawgrass community (25 percent land coverage) is characterized by the saw-edged sedge that dominates this type of habitat. Sawgrass may grow in solid stands, mosaics or interspersed with other species such as wax myrtle and dahoon holly. Sawgrass areas often border tree islands, separating them from the wet prairie (Lodge 1994). Tree Islands The northern portion of the refuge is characterized with thousands of tree islands that range from less than 1 acre to more than 300 acres. There is approximately 20 percent of the refuge interior covered with tree islands. They are typically composed of an overstory of redbay and dahoon holly with wax myrtle, buttonbush and cocoplum comprising a dense midstory and numerous ferns in the understory. Tree islands form when submerged peat patches rise to the water’s surface and small plants become established followed by shrubs and trees. During drought conditions, alligators wallow out a circular deep water refugia, called “alligator holes.” Wind blown herbaceous seeds germinate on the exposed peat and eventually woody vegetation grows on the edges and creates a tree island with a “doughnut shape.” Alligator holes are very important aquatic refugia during the dry season and are sources for fish and other aquatic organisms’ population reestablishment after summer rain rehydrates the ecosystem (Lodge 1994). A vast number of tree islands have been impacted by invasive exotic plants. 30 A.R.M. Loxahatchee National Wildlife Refuge Comprehensive Conservation Plan Figure 8. Vegetative communities of A.R.M. Loxahatchee National Wildlife Refuge (Adapted from Richardson et al., 1990) Comprehensive Conservation Plan 31 Cypress Swamp On the eastern edge of the refuge is a 400-acre cypress swamp community which is composed of pond cypress trees, pond apple, myrsine, lichens and ferns such as giant leather, sword, shield, strap, royal, resurrection and swamp ferns. The moist microclimate of the cypress swamp also provides for a profusion of epiphytes (air plants), such as cardinal, giant, reflexed and twisted wild pine and Spanish moss. This cypress swamp is the largest remaining remnant of a community on the east side of the Everglades whose former range extended from Lake Okeechobee through Palm Beach and northern Broward counties, south to Fort Lauderdale (Lodge 1994). The cypress swamp includes 20 species of trees and shrubs, 20 herbs, 9 vines, 1 sedge, 14 ferns, 7 bromeliads and 2 lichens (Fish and Wildlife Service 1987b). (See Appendix K). Cattail Two native species of cattail grow on the refuge. Naturally growing cattails can be found surrounding wading bird colonies, roost tree islands, and alligator holes. The cattail growth is dependent upon the intense pulse of nutrients deposited by the concentration of nesting birds. After a tree island is abandoned by nesting birds, cattails often die back because of the loss of nutrients (Fish and Wildlife Service 1998c).In response to years of artificially high levels of nutrients (phosphorous) in the water, a dense stand of cattails has been established along the perimeter canal. Near the S-6 water structure, monotypic stands of cattail growth are approximately 1⁄2 mile deep. This water, received from the S-5A and S-6 pump stations, originates from the agricultural fields to the north and west of the refuge. Attempts to reduce the nutrient load in water and lessen the negative impacts to the refuge are on-going (see Part II, Significant Resource Problems and Part III, Water Quality). Wildflowers At least 50 wildflower species (exotic and native) can be found in marsh areas of the refuge (Fish and Wildlife Service 1987). Common types found are Spanish needle, arrowhead, buttonbush, string and spider lilies, elderberry, lizard’s tail and scorpiontail, pickerelweed and primrose willow. Exotic Plants Invasive exotic plants, such as Brazilian pepper, melaleuca, and Old World climbing fern, pose a serious threat to the whole south Florida ecosystem, to native plant communities, wildlife habitats, threatened and endangered species, and species of special concern on the refuge. Floating exotic plants, such as water lettuce and water hyacinth, threaten to clog refuge canals restricting navigation, water flow, and water drainage. These alien plants, lacking natural predators and insects to keep them in check, rapidly expand forming dense, monotypic forests and thickets which are undesirable to humans and wildlife. This degraded habitat has been proven to support less species diversity than native plant habitats. Generally, exotic plants in south Florida tend to establish in “disturbed” areas such as abandoned farm fields, along roadways, canals, and drainage ditches, and in wetlands which have been altered or stressed due to hydroperiod changes (Ferriter 1998). Melaleuca and Old World climbing fern are, however, not restricted to areas of disturbance. Since the climate and conditions of south Florida are similar to conditions for melaleuca and Old World climbing fern in their native countries, these plants have rapidly become established in pristine areas. Management of invasive pest plants is one of the priorities established by the South Florida Ecosystem Restoration Task Force. As a result of these priorities, the task force and working group have authorized and funded the Noxious Exotic Weed Task Team to develop the comprehensive strategic plan for the management of exotic pest plants in Florida (with emphasis on south Florida). The team members are managers and scientists from key federal, state, and local agencies that deal directly with exotic pest plants (Doren 1998). The State of Florida Everglades Forever Act of 1994, requires the South Florida Water Comprehensive Conservation Plan 32 A.R.M. Loxahatchee National Wildlife Refuge Management District to coordinate with other state, local, and federal government entities to manage exotic pest plants with emphasis in the Everglades Protection Area (all areas from the Everglades Agricultural Area south to the Everglades National Park).The Florida Chapter of Exotic Pest Plant Council, established in 1982, documents the spread of exotic pest plants and unifies the exchange of information between land management agencies, research scientists, industry and other interest groups who are concerned with the impacts of exotic plants in natural areas (Laroche 1994). Category I plants are species that are currently invading and disrupting native plant communities in Florida. The refuge has 21 Category I plants (Table 24). Category II plants are species that have shown a potential to disrupt native plant communities, and the refuge has at least nine of these (Table 25). Refuge staff will remain actively involved with organizations such as the Florida Exotic Pest Plant Council, Southeast Florida Exotic Pest Plant Council, and the South Florida Invasive Plant Working Group and adopt the strategies for exotic plant management recommended by these organizations. The refuge will update its melaleuca management plan by 2002 to incorporate the methods and strategies of the South Florida Water Management District’s melaleuca management plan originally drafted in 1990. By following the strategies of this plan, the South Florida Water Management District has almost completed initial treatments of melaleuca on all their lands and surveys have indicated a 26 percent decrease in melaleuca populations particularly in the water conservation areas and Lake Okeechobee from a high of 488,000 acres in 1993, to 361,000 acres in 1999. Melaleuca Melaleuca, a native of Australia, was originally introduced in southeast and southwest Florida in 1906 (Meskimen 1962) as an ornamental plant. At one time, people believed the tree could assist in draining water from the Everglades because water is rapidly taken up, used in photosynthesis and released into the air as a vapor (transpiration). It is thought that the area that became the refuge and Ft. Meyers on Florida’s west coast were heavily seeded by airplane. In the 1930s and 1940s, trees were planted along the rim canal of Lake Okeechobee and at the Monroe station, Big Cypress National Preserve (Laroche 1994). Although the greatest concentrations are found in areas of historical introductions, the refuge has one of the highest concentrations of melaleuca in all of the south Florida ecosystem. In Strazzulla Marsh, melaleuca has invaded the cypress swamp and domes, sawgrass, and wet prairies; nearly 50 percent of this area has been affected. In the refuge interior, melaleuca has invaded native tree islands, sawgrass, sloughs, and wet prairies. The most recent aerial survey in 1995, estimated that 49 percent (71,000 acres) of the refuge interior was moderately to heavily infested. Using 1992 data as a comparison, melaleuca is calculated to be expanding at the rate of 10 acres per day. The history of melaleuca throughout the Everglades ecosystem, including the refuge, is one of “an explosion in slow motion” (Laroche 1994). From the 1960s to the early 1980s, melaleuca grew at an exponential rate. Areas occupied by a single, isolated “pioneer” tree soon developed into acres of dense “heads” and Melaleuca “hack and squirt” Photo © John and Karen Hollingsworth Comprehensive Conservation Plan Comprehensive Conservation Plan 33 Comprehensive Conservation Plan Figure 9. 1992 Melaleuca Aerial Survey Results 34 A.R.M. Loxahatchee National Wildlife Refuge Figure 10. 1995 Melaleuca Aerial Survey Results Comprehensive Conservation Plan Comprehensive Conservation Plan 35 monotypic forests. By the mid- to late-1970s, melaleuca had spread to all areas of the refuge. It was the Refuge Manager’s opinion that if an effective treatment technique could not be found, melaleuca would certainly take over the refuge. With no natural enemies in south Florida, such as disease or insects to control its spread, and an ideal growing climate, melaleuca now threatens to permanently replace and eliminate native Everglades flora and fauna. As indicated above, melaleuca primarily invades disturbed areas but is particularly prevalent in Florida wetlands; i.e., the refuge, where hydroperiods have been artificially shortened or altered. In addition to the above effects, live melaleuca inhibits the use of prescribed fire as a management tool since the volatile oils in melaleuca leaves would produce intense, uncontrollable fires. Furthermore, the use of fire would generate a massive seedfall which would allow the tree to become quickly established in adjacent areas. The raging wildfire during the drought of 1989-90, certainly contributed to the exponential spread of melaleuca in the refuge interior. The primary management tool used at the refuge for the control of melaleuca is herbicides. At the present time, the chief treatment method involves felling mature trees using chainsaws followed by treatment with 50 percent Arsenal® diluted in water. Follow-up visits are necessary to prevent reinfestation. Since an intensive herbicide program was established in 1992, refuge staff have eradicated more than 2,209,000 of these trees on refuge lands at an annual cost exceeding $200,000, funded by the Service and the District. An estimated 6,400 acres have been cleared of melaleuca. Unfortunately, refuge staff can only treat about 1⁄2- to 1-acre-per-day, which is having a limited effect on the 10-acre-per-day advance of melaleuca on the refuge. Since herbicidal treatments are labor intensive and costly and melaleuca can easily re-infest cleared areas, biological control offers an alternative (Center et al., 1998). In 1999, the refuge switched to using private contractors for exotic plant control for both melaleuca and Old World climbing fern after refuge staff consulted with the National Park Service, the Department of Environmental Protection, the South Florida Water Management District, and other local agencies and made the determination that using private contractors was the most cost effective means to eradicate exotic plants. To better incorporate the philosophy of an integrated pest management approach, the refuge has increased its role and effort concerning public outreach and awareness by identifying the dangers and risks associated with the introduction of exotic plants. Programs by individuals directly involved with exotic plant management are scheduled as part of the “Calender of Events” at the visitor center and these presentations are free to the general public. Refuge staff schedule programs and slide presentations for environmental education groups and for local chapters of national organizations such as the Audubon Society. The refuge will continue to push for more exotic plant control funding, a limiting factor to successful exotic plant management. This will be done by keeping this issue a high priority and informing all levels of the Service about resource impacts and budget needs. Several key refuge personnel serve as members on regional invasive species teams and ecosystem restoration task forces where key exotic plant issues are addressed. The refuge’s exotic plant problems are frequently addressed in local and national newspapers, magazines and on national and Service web sites. Within the past few years, U.S. Department of Agriculture research scientists have begun to research insects from Australia as possible controls of melaleuca. The snout beetle, was released on the refuge and other parts of south Florida in the spring of 1997. Unfortunately the beetle cannot survive and reproduce in the wet habitat of the refuge. A second biological control, the defoliating sawfly, is scheduled for release in 2000. Shipments were sent to the quarantine facility in 1992-1993. The Environmental Assessment is currently being reviewed pending approval Comprehensive Conservation Plan 36 A.R.M. Loxahatchee National Wildlife Refuge by the Service’s Washington Office. This sawfly offers the best hope for melaleuca control. Both adults and larvae feed voraciously on foliage of the tree eventually causing complete de-foliage. The insects entire life cycle occurs on the melaleuca tree, above ground. Larva pupate within the bark of the tree. Researchers have been reluctant to release this insect due to its noticeable damage as many people still have melaleuca growing in their yards as ornamentals. Additionally, its release has been delayed because the larvae have proven to be toxic, when consumed in large quantities, by some wildlife and domestic animals. Studies and research into this matter are continuing at this time. Evidently the larvae store a toxic chemical in their system as they feed (Lophrytonin) and it becomes more concentrated as they age. Alternative methods for exotic plant control on the refuge other than chemical, physical |
| Tag | Library-Source-CCPs |
| Date created | 2012-10-16 |