Hobe Sound National Wildlife Refuge Comprehensive Conservation Plan

              Hobe Sound
National Wildlife Refuge
Photo taken by Margo Stahl
USFWS Photo
S N W R
Comprehensive Conservation Plan
Photo provided by
U.S. Fish & Wildlife Service
Comprrehensiive Conserrvattiion Pllan
Hobe Sound National Wildlife Refuge
P.O. Box 645 􀁺􇩈 Hobe Sound, FL 733475-0645
Telephone: (772) 546-6141
Fax: (772) 545-7572
email: HobeSound@fws.gov
U.S. Fish & Wildlife Service
1 800/344 WILD
http://www.fws.gov
January 2007
Photo provided by
Jim Abernethy’s Scuba Adventures
Comprehensive Conservation Plans provide long-term guidance for
management decisions; set forth goals, objectives, and strategies
needed to accomplish refuge purposes; and identify the Fish and
Wildlife Service's best estimate of future needs. These plans detail
program planning levels that are sometimes substantially above
current budget allocations and, as such, are primarily for Service
strategic planning and program prioritization purposes. The plans
do not constitute a commitment for staffing increases, operational
and maintenance increases, or funding for future land acquisition.
Hobe Sound National Wildlife Refuge
Comprehensive Conservation Plan
U.S. Department of the Interior
Fish and Wildlife Service
Southeast Region
December 2006
HOBE SOUND NATIONAL WILDLIFE REFUGE
COMPREHENSIVE CONSERVATION PLAN
U.S. Department of the Interior
Fish and Wildlife Service
Southeast Region
Atlanta, Georgia
January 2007
Hobe Sound National Wildlife Refuge i
TABLE OF CONTENT
SECTION A. COMPREHENSIVE CONSERVATION PLAN
I. BACKGROUND .................................................................................................................................. 1
Introduction .................................................................................................................................... 1
Purpose Of and Need For The Plan .............................................................................................. 2
Planning Process ........................................................................................................................... 2
Fish and Wildlife Service ................................................................................................................ 3
National Wildlife Refuge System .................................................................................................... 4
Hobe Sound National Wildlife Refuge ........................................................................................... 4
Location, Establishment, and Importance ............................................................................ 4
Refuge Purposes .................................................................................................................. 7
Facilities .............................................................................................................................. 11
Staffing and Funding........................................................................................................... 11
Ecosystem and North American Context ........................................................................... 11
Legal and Policy Guidance ................................................................................................. 16
II. PLANNING ISSUES AND OPPORTUNITIES .................................................................................. 19
Introduction .................................................................................................................................. 19
Identifying the Issues .................................................................................................................... 19
Wildlife Habitat Management ............................................................................................. 19
Public Use: Recreation ....................................................................................................... 20
Public Use: Education and Public Awareness ................................................................... 22
Partnerships ........................................................................................................................ 22
Historical Resources ........................................................................................................... 22
Administration ..................................................................................................................... 23
Significant Refuge Issues ............................................................................................................. 24
Visitor Use ........................................................................................................................... 24
Resource Protection ........................................................................................................... 24
Administration ..................................................................................................................... 26
III. REFUGE ENVIRONMENT .............................................................................................................. 27
Physical Environment ................................................................................................................... 27
Climate ............................................................................................................................... 27
Air Quality ............................................................................................................................ 27
Noise/Traffic ........................................................................................................................ 27
Geology and Soils ............................................................................................................... 28
Hydrology ............................................................................................................................ 29
Water Quality ...................................................................................................................... 29
Biological Environment ................................................................................................................. 30
Mainland Tract .................................................................................................................... 30
Indian River Lagoon ............................................................................................................ 38
Jupiter Island Tract ............................................................................................................. 42
Exotic Species .................................................................................................................... 51
Socioeconomic Environment ........................................................................................................ 52
History of Martin County ..................................................................................................... 52
Land Use and Values ......................................................................................................... 56
Demographics ..................................................................................................................... 56
Resource Economics .......................................................................................................... 58
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Recreation Use ................................................................................................................... 58
Cultural Environment .................................................................................................................... 62
Prehistoric Influences ......................................................................................................... 62
Historic Influences .............................................................................................................. 62
Modern Influences .............................................................................................................. 63
IV. MANAGEMENT DIRECTION .......................................................................................................... 65
Introduction .................................................................................................................................. 65
Refuge Vision ............................................................................................................................... 65
Refuge Goals ............................................................................................................................... 66
Comprehensive Conservation Plan Summary ............................................................................. 66
Goals, Objectives, and Strategies ................................................................................................ 67
Goal 1. Wildlife Habitat and Population Management ...................................................... 67
Goal 2. Resource Protection ............................................................................................. 72
Goal 3. Wildlife-Dependent Recreation and Environmental Education ............................ 74
Goal 4. Administration ....................................................................................................... 78
V. PLAN IMPLEMENTATION .............................................................................................................. 81
Introduction .................................................................................................................................. 81
Project Summaries ....................................................................................................................... 81
Staffing and Funding .................................................................................................................... 88
Partnership Opportunities ............................................................................................................ 89
Step-Down Management Plans ................................................................................................... 91
Monitoring and Evaluation ............................................................................................................ 94
Plan Review and Revision ........................................................................................................... 94
SECTION B. APPENDICES
I. GLOSSARY ...................................................................................................................................... 95
II. REFERENCES AND LITERATURE CITED ................................................................................... 103
III. LEGAL MANDATES ...................................................................................................................... 109
IV. REFUGE BIOTA ............................................................................................................................ 117
V. PUBLIC INVOLVEMENT ................................................................................................................ 137
Summary Of Public Scoping Comments.................................................................................... 137
Draft Plan Comments and Service Response ........................................................................... 147
VI. COMPATIBILITY DETERMINATIONS ......................................................................................... 167
VII. INTRA-SERVICE SECTION 7 BIOLOGICAL EVALUATION ...................................................... 177
VIII. SUBTROPICAL FLORIDA PARTNERS-IN-FLIGHT BIRD CONSERVATION PLAN:
SECTION 2 AVIFAUNAL ANALYSIS .......................................................................................... 203
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IX. EXISTING AND POTENTIAL PARTNERS ................................................................................... 211
X. CONSULTATION AND COORDINATION ..................................................................................... 213
XI. FINDING OF NO SIGNIFICANT IMPACT ..................................................................................... 215
iv Table of Contents
LIST OF FIGURES
Figure 1. Location of Hobe Sound National Wildlife Refuge in relation to other refuges with similar
habitats in Florida .................................................................................................................... 5
Figure 2. Location of Hobe Sound National Wildlife Refuge in relation to adjacent state lands ........... 6
Figure 3. Location of Jupiter Island and mainland tracts of Hobe Sound National Wildlife Refuge in
relation to Indian River Lagoon/Intracoastal Waterway .......................................................... 8
Figure 4. Jupiter Island tract of Hobe Sound National Wildlife Refuge and the Indian River Lagoon, in
the context of community development .................................................................................. 9
Figure 5. Mainland tract of Hobe Sound National Wildlife Refuge and the Indian River Lagoon,in the
context of community development ....................................................................................... 10
Figure 6. Upper east coast ecosystem subregion within the South Florida Ecosystem ...................... 12
Figure 7. High priority bird species abundance and seasonal use, Hobe Sound National Wildlife
Refuge .................................................................................................................................. 14
Figure 8. Vegetation on mainland tract, Hobe Sound national Wildlife Refuge ................................... 31
Figure 9. General distribution of scrub in Florida, adapted from Davis, 1967 .................................... 32
Figure 10. Location of seagrass beds in relation to Hobe Sound National Wildlife Refuge ................ 41
Figure 11. Vegetation on Jupiter Island tract, Hobe Sound National Wildlife Refuge ......................... 43
Figure 12. Location of mosquito impoundments, F1, F2, and F3, on Hobe Sound National Wildlife
Refuge ................................................................................................................................. 46
Figure 13. Number of sea turtle nests observed on refuge by species 1991-2002 ............................. 47
Figure 14. Annual number of green turtle (Chelonia Mydas) nests, Hobe Sound National Wildlife
Refuge, 1973-2002. Data analysis by Ecological Associates, Inc. .................................... 47
Figure 15. Annual number of loggerhead turtle (Caretta caretta) nests, Hobe Sound National Wildlife
Refuge, 1973-2002. Data analysis by Ecological Associates, Inc. .................................... 48
Figure 16. Annual loggerhead turtle (Caretta caretta) hatchling productivity, Hobe Sound National
Wildlife Refuge, 1997-2002. Data analysis by Ecological Associates, Inc. ....................... 48
Figure 17. Percentage of marked sea turtle nests depredated, Hobe Sound National Wildlife Refuge,
1997-2002. Data analysis by Ecological Associates, Inc. .................................................. 50
Figure 18. Exotic wildlife reported on Hobe Sound National Wildlife Refuge ...................................... 53
Figure 19. Exotic vegetation on Mainland Tract, Hobe Sound National Wildlife Refuge .................... 54
Figure 20. Exotic vegetation on Jupiter Island Tract, Hobe Sound National Wildlife Refuge ............. 55
Figure 21. Socioeconomic profile of Martin County, Florida 1980-2000 .............................................. 57
Figure 22. Location of recreational and administrative facilities at Hobe Sound National Wildlife
Refuge ................................................................................................................................. 60
Figure 23. Summary of public use on Hobe Sound National Wildlife Refuge* .................................... 61
Figure 24. Proposed wildlife habitat and population management activities for Hobe Sound National
Wildlife Refuge ..................................................................................................................... 69
Figure 25. Location of existing and proposed recreational and administrative facilities on Hobe Sound
National Wildlife Refuge ...................................................................................................... 76
Figure 26. Summary of project costs for Hobe Sound National Wildlife Refuge ................................. 82
Figure 27. Annual cost of existing and proposed staff positions for Hobe Sound National Wildlife
Refuge ................................................................................................................................. 90
Figure 28. Step-down management plans/completion dates ............................................................... 93
Hobe Sound National Wildlife Refuge 1
SECTION A. COMPREHENSIVE CONSERVATION PLAN
I. BACKGROUND
INTRODUCTION
The Hobe Sound National Wildlife Refuge sits as an oasis of pre-contact Florida ecology bisecting the
burgeoning urban growth centers to the north and south of the cities of Jacksonville and Miami,
respectively. Part of the refuge is situated atop ancient sand dunes that reflect the cycles of
deposition and erosion in response to sea-level changes during the last 65 million years. These
dunes and their associated lagoons served as important ecological environments that provided
subsistence to tribal groups living here prior to European colonization and American settlement. Early
in the 20th century, the rush to develop Florida resulted in a great loss of native habitats. However,
this refuge=s very existence was borne out of the vision of conservation-minded residents who
conveyed lands to the Fish and Wildlife Service in an effort to preserve and protect such rare and
threatened species as mermaid-like manatees; chattering scrub jays; and lumbering, gargantuan
leatherback sea turtles. In an effort to protect the ecosystems at Hobe Sound, one of those settlers,
Joseph V. Reed, established the Reed Wilderness Seashore Sanctuary in 1967, a registered national
landmark. This sanctuary is located at the north end of what is now Hobe Sound National Wildlife
Refuge. The refuge is located not far from Pelican Island, the birthplace of the National Wildlife
Refuge System, where 100 years ago, President Theodore Roosevelt in essence made a promise to
the American people to set aside a network of lands and waters for wildlife.
The Fish and Wildlife Service has developed this Comprehensive Conservation Plan for Hobe Sound
National Wildlife Refuge to guide management and resource use over the next 15 years. The refuge
vision focuses on protecting wildlife and plants and promoting stewardship of all natural resources
through public participation and partnerships. To carry out this vision, the plan identifies funding,
staffing, and operation and maintenance needs of the refuge.
The plan=s overriding consideration is to carry out the purposes for which the refuge was established.
Fish and wildlife resources are the first priority in refuge management, while public use (appropriate
wildlife-dependent recreation) is allowed and encouraged, as long as it is compatible with, or does not
detract from, the refuge=s mission and purposes.
Major issues addressed in this plan include the following:
 Ever-present threat of invasion by exotic species;
 Need to promote biological diversity;
 Context of land-use changes around the refuge boundaries;
 General habitat and wildlife protection;
 Recreational opportunities and public access;
 Environmental education; and
 Community/interagency partnerships.
Based on these issues, a range of alternatives was identified that could be implemented within the
time frame of the plan. From these alternatives, the Service has selected a recommended course of
action for managing the refuge. This plan contributes to the achievement of the South Florida
Ecosystem Plan, the South Florida Multi-Species Recovery Plan, and the Partners-in-Flight Initiative.
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PURPOSE OF AND NEED FOR THE PLAN
As directed by the National Wildlife Refuge System Improvement Act of 1997, comprehensive
conservation plans are to be developed for all national wildlife refuges by 2012. This plan for Hobe
Sound National Wildlife Refuge will identify the role of the refuge in supporting the mission of the
National Wildlife Refuge System, and 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.
The plan is needed to:
$ Articulate a vision statement, framing future management of the refuge;
$ Provide refuge neighbors, visitors, the public, and government officials with an understanding
of the Service=s management actions within 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; and
$ Provide a basis for the development of annual budget requests for operational, maintenance,
and capital improvement needs.
This comprehensive conservation plan has been developed to address important natural
resource, compatible wildlife-dependent recreation, and administrative needs. To be specific,
there is a need to restore and conserve diverse habitats, species populations, and biological
integrity; conserve natural and cultural resources through partnerships, protection, and land
acquisition from willing sellers; provide opportunities for appropriate, compatible wildlife-dependent
recreation, environmental education, and interpretive programs; and provide effective
and efficient administration of the refuge.
PLANNING PROCESS
This comprehensive conservation plan outlines a new vision for the refuge and combines two
documents that are required by federal lawBa comprehensive conservation plan required by the
National Wildlife Refuge System Improvement Act of 1997, and an environmental assessment
required by the National Environmental Policy Act of 1969, as amended.
In compliance with these Acts, the refuge has been actively seeking public involvement in its
comprehensive planning. The Acts also require the Service to seriously consider all reasonable
alternatives to major actions on refuges, including a Ano action@ alternative.
In developing this plan, the Service completed a 4-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 opportunities, concerns, and issues relating
to the future management of the refuge;
3. Prepared a draft plan for public review and comment; and
4. Incorporated public review as appropriate
On July 16-17, 1998, the Service assembled a planning team at the refuge headquarters to begin the
scoping process for developing a draft plan for the Hobe Sound National Wildlife Refuge. The
Hobe Sound National Wildlife Refuge 3
planning team was composed of representatives from the Service, Florida Department of
Environmental Protection, Florida Park Patrol, Florida Fish and Wildlife Conservation Commission,
South Florida Water Management District, Martin County, Town of Jupiter Island, University of Florida,
and Florida Atlantic University. The planning team members are listed in Section B, Environmental
Assessment.
The team developed a draft 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 management direction of the refuge and planned the agenda for a public scoping meeting.
The public scoping meeting was held in Hobe Sound, Florida, on August 18, 1998. Attendees of this
meeting identified a variety of issues, concerns, and opportunities for future management of the
refuge. The comments from the public scoping meeting and those expressed on the comment sheets
are summarized in Appendix V.
Following the identification of the issues and opportunities, the planning team began the process of
preparing sections of the draft plan and environmental assessment. Information concerning the
refuge=s physical, biological, and socioeconomic environment was compiled and is described in
Chapter III, Refuge Environment.
At subsequent planning team meetings, possible alternatives for the management of the refuge were
identified. This planning process uncovered the additional need over the next few years to acquire
remaining tracts of lands that might be developed and lost to wildlife protection as a result of the
urban and suburban development that continues to sprawl across Florida.
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 on
February 26, 2004, to present the pros and cons of each alternative and to obtain additional
comments from the public.
FISH AND WILDLIFE SERVICE
Although the Fish and Wildlife Service is the primary federal agency responsible for conserving,
protecting, and enhancing the Nation=s fish, wildlife, and plant populations and their habitats, it
shares these responsibilities with other federal, state, tribal, local, and private entities. The Service
enforces federal wildlife laws, administers the Endangered Species Act, manages migratory bird
populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as
wetlands, and helps foreign governments with their conservation efforts. It also oversees the Federal
Aid Program that distributes hundreds of millions of dollars in excise taxes on fishing and hunting
equipment to state fish and wildlife agencies.
The mission of the Fish and Wildlife Service is to work with others to conserve, protect, and enhance
fish, wildlife, and plants and their habitats for the continuing benefit of the American people. As part of
its mission, the Service operates more than 540 national wildlife refuges covering over 95 million
acres. These areas comprise the National Wildlife Refuge System, the world=s largest collection of
lands specifically managed for fish and wildlife. The system supports over 800 species of birds, 220
species of mammals, 250 reptiles and amphibians, 1,000 fish, and countless species of invertebrates
and plants. Of course, a primary importance is the recovery of 282 threatened or endangered species
found on refuge lands.
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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 Ato 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 purposes of each refuge; and maintain the biological integrity, diversity, and
environmental health of the system.
While wildlife will have first priority in refuge management, appropriate and wildlife-dependent
recreational uses (e.g.,, hunting, fishing, wildlife observation, wildlife photography, and environmental
education and interpretation) or other uses may only be allowed after they have been determined, by
the refuge manager, to be a compatible use. Further, appropriate and wildlife-dependent recreational
uses are legitimate and priority public uses and are to receive enhanced consideration over other
public uses in planning and management.
National wildlife refuges provide important habitats for native plants and many species of mammals,
birds, fish, amphibians, reptiles, insects, and invertebrates. They also play a vital role in protecting
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
the year 2000, more than 30 million people visited national wildlife refuges to hunt, fish, observe and
photograph wildlife, and participate in educational and interpretive activities (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.
HOBE SOUND NATIONAL WILDLIFE REFUGE
LOCATION, ESTABLISHMENT, AND IMPORTANCE
Hobe Sound National Wildlife Refuge is one of the few remaining publicly owned sand pine scrub
communities and one of the largest contiguous sections of undeveloped beach in southeastern
Florida. Refuge habitats are important to threatened and endangered species such as the scrub jay
and sea turtles, which are also found at Lake Wales Ridge, Pelican Island, Archie Carr, and Merritt
Island National Wildlife Refuges (Figure 1).
Hobe Sound Refuge is in southeastern Martin County, near the town of Hobe Sound, Florida
(Figure 2). Figure 2 highlights the approved acquisition area of the refuge. There are two small tracts
of land in St. Lucie County that are also within this acquisition boundary. Jonathan Dickinson, Atlantic
Ridge, Seabranch Preserve, and St. Lucie Inlet Preserve state parks are in the immediate vicinity of
the refuge. Personnel at these state parks and those at Hobe Sound Refuge collaborate in their
efforts to restore and maintain sand pine scrub habitat, as well as to protect threatened and
endangered species of plants and animals.
Hobe Sound National Wildlife Refuge 5
Figure 1. Location of Hobe Sound National Wildlife Refuge in relation to other refuges with
similar habitats in Florida
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Figure 2. Location of Hobe Sound National Wildlife Refuge in relation to adjacent state lands
Hobe Sound National Wildlife Refuge 7
A close-up view shows that the refuge is bisected by the Indian River Lagoon into two tractsBa
Mainland Tract and the Jupiter Island Tract (Figure 3). The Mainland Tract is bordered on the west by
U.S. Highway 1 and Jonathan Dickinson State Park, on the east by the Indian River Lagoon, and on
the north and south by private landowners. The Jupiter Island Tract shares its northern boundary with
St. Lucie Inlet Preserve State Park and its southern boundary with private landowners.
The portions of the Indian River Lagoon adjacent to the refuge are more commonly known as Hobe
Sound, Peck Lake, and the Intracoastal Waterway. The Indian River Lagoon, which is
inhabited by the endangered West Indian manatee, has been designated as an estuary of national
importance. Major threats to the lagoon=s ecosystem are excess nutrients, sediment loads, and toxic
chemicals associated with intensive development along its shores (Figures 4 and 5).
The refuge was established in 1969, through the foresight and generosity of the Joseph V. Reed
Family and other Jupiter Island residents, with an approved acquisition boundary of approximately 400
acres. The refuge originated from its designation as the Reed Wilderness Seashore Sanctuary and
its National Landmark status in 1967. Today, the refuge consists of more than 1,000 acres, including
the 300-acre Mainland Tract and the 735-acre Jupiter Island Tract. Most of the refuge was donated
by private citizens and The Nature Conservancy primarily for the conservation of threatened and
endangered species and preservation of undeveloped vistas.
The refuge provides habitat for nearly 40 species listed as either threatened, endangered, or species
of special concern by the state or federal government. Of particular importance to these species is
the largest remnant of sand pine scrub habitat, the nearly 10 miles of mangrove communities along
the Indian River Lagoon, and 3.5 miles of Atlantic Ocean beach. This beach is one of the most
productive sea turtle nesting areas in the southeastern United States.
REFUGE PURPOSES
As indicated in the legislation authorizing the establishment of the refuge, and in land acquisition
authorities and documents, the conservation of threatened and endangered fish, wildlife, and plants is
paramount. Development of fish and wildlife-oriented recreational opportunities must consider this
conservation mandate.
The refuge was established A...to conserve (A) fish or wildlife which are listed as endangered species or
threatened species... or (B) plants....@ 16 U.S.C.1534 (Endangered Species Act of 1973); A...suitable for (1)
incidental fish and wildlife-oriented recreational development, (2) the protection of natural resources, (3) the
conservation of endangered species or threatened species....@ 16 U.S.C. 460K-1 (Refuge Recreation Act
of 1962); A...for use as an inviolate sanctuary, or for any other management purpose, for migratory birds.@
16 U.S.C. 715d (Migratory Bird Conservation Act of 1929); A...conservation, management, and restoration
of the fish, wildlife, and plant resources and their habitats for the benefit of present and future generations
of Americans.@ (16 U.S.C. 668dd(a)(2) (National Wildlife Refuge System Administration Act of 1966);
A...for the development, advancement, management, conservation, and protection of fish and wildlife
resources.@ 16 U.S.C. 742f(a)(4) (Fish and Wildlife Act of 1956).
This purpose and the mission of the National Wildlife Refuge System are fundamental to determining the
compatibility of proposed uses of the refuge. The compatibility of these uses is discussed in Appendix VI.
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Figure 3. Location of Jupiter Island and mainland tracts of Hobe Sound National Wildlife
Refuge in relation to Indian River Lagoon/Intracoastal Waterway
Hobe Sound National Wildlife Refuge 9
Figure 4. Jupiter Island tract of Hobe Sound National Wildlife Refuge and the Indian River
Lagoon, in the context of community development
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Figure 5. Mainland tract of Hobe Sound National Wildlife Refuge and the Indian River
Lagoon,in the context of community development
Hobe Sound National Wildlife Refuge 11
FACILITIES
The headquarters area, the main entrance to the refuge, is 2 miles south of County Road 708 on U.S.
Highway 1 (Figure 3). Under construction at this time, the headquarters of the refuge will consist of a
new administration and visitor center building, an environmental education classroom, two residential
buildings, and a maintenance building. Located at this site is a Seminole chickee (an open pavilion),
which serves as an environmental study and staging area for visitors who use the sand pine scrub trail
or access trail to the Indian River Lagoon.
The original administration building, constructed in the 1950s as a motel, was destroyed during the
2004 hurricane season. It provided limited space for refuge personnel and the Hobe Sound Nature
Center, Inc. Established in 1973, the Hobe Sound Nature Center is a non-profit environmental
education organization and a cooperating association of the refuge. The new headquarters will
contain office space for both the refuge staff and Nature Center personnel, as well as a larger
interpretive museum for the public. The Jackson Burke Education Center was constructed in 1998,
with funds raised by the Nature Center. The Nature Center is actively involved in public outreach
programs, which support and foster the refuge. Due in large part to this relationship, the refuge
enjoys a great deal of public support.
The refuge beach, the second entrance to the refuge, is located on Jupiter Island approximately 1.5
miles north of the intersection of County Road 708 and North Beach roads (Figure 3). This entrance
contains a paved parking lot, entrance fee booth, primitive restroom facilities, two dune cross-over
boardwalks, and a foot trail to the beach.
STAFFING AND FUNDING
Hobe Sound Refuge is a minimally staffed satellite of the A.R.M. Loxahatchee National Wildlife
Refuge in Boynton Beach, Florida. The Hobe Sound Refuge staff is made up of three permanent
employees: a manager, a law enforcement officer, and a maintenance worker. The staff is
supplemented by seasonal positions, including a biological technician, maintenance worker, and two
fee rangers. The refuge shares its budget with Loxahatchee Refuge, which in Fiscal Year 2006
totaled over $4 million for payroll and operation needs, and an additional $8 million in special or one-time
funding. Hobe Sound Refuge operates on approximately $225,000 per year.
ECOSYSTEM AND NORTH AMERICAN CONTEXT
Role of the Refuge in the South Florida Ecosystem
In recognition of the ecosystem complexity in south Florida, a South Florida Ecosystem Plan was completed
by the Service=s South Florida Ecosystem Team (Fish and Wildlife Service 1998). This plan identified the
goals, objectives, and strategies for this ecosystem and the major issues associated with eight ecosystem
sub-regions. The plan is one of the first such efforts specifically targeted at recovering multiple species over a
large geographic area. Management activities on the refuge, located in the Upper East Coast Ecosystem
Subregion (Figure 6), are consistent with the South Florida Ecosystem Plan. These activities include the
reduction of exotic and invasive species; enforcement of laws to protect wildlife resources on the refuge;
coordination with other agencies regarding the Intracoastal Waterway and its many issues; promotion of public
awareness about the imperiled scrub ecosystem; provision of appropriate wildlife-compatible recreation; and,
maintenance of facilities and equipment at or above Service standards.
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Figure 6. Upper east coast ecosystem subregion within the South Florida Ecosystem
Hobe Sound National Wildlife Refuge 13
The refuge is represented on the South Florida Ecosystem Team, which is comprised of Service field
stations in an area from Vero Beach, south to the Florida Keys, and west to Ft. Myers. This diverse team
works together to accomplish Service priorities, which include protection and management of federal trust
species through the sharing of skills, expertise, equipment, and personnel for special projects.
Recently, the refuge has taken a more active role in partnership efforts to protect and enhance
habitats and wildlife, both on and off the refuge. Staff have participated on committees to heighten
public awareness of the following: feral cat impacts on wildlife; damaging effects of bright lights on
sea turtle nesting success; damaging and costly problems caused by exotic animals and plants;
actively managing the imperiled coastal scrub plant community; and efforts to enhance the dwindling
estuarine habitats and seagrass beds.
Since more than 91 percent of endemic scrub habitat has been lost from south Florida, active
management of refuge=s scrub is vitally important to the multi-species approach to ecosystem
management. In recent years, the staff has improved working associations with other natural resource
agencies. This concentrated effort established new partnerships and has directly benefited the refuge=s
ability to manage the scrub habitat as a part of a landscape mosaic, instead of as an isolated tract. This
encompassing foresight will improve scrub conditions on the refuge and on other undeveloped lands where
the refuge may have cooperative agreements in the upper coast of south Florida.
Role of the Refuge in Restoration of the Indian River Lagoon
The Intracoastal Waterway immediately bordering the Hobe Sound Refuge headquarters is one of the
most productive and species-rich portion of the Indian River Lagoon, which is considered the most
productive estuary in the United States. North of the headquarters, the lagoon drains into the Atlantic
Ocean at the St. Lucie Inlet, where the refuge beach tract is located. To the south of the refuge, the lagoon
connects to the Atlantic Ocean at Jupiter Inlet. The draining of the Everglades in the early 20th century
resulted in large freshwater flows into the lagoon, wreaking environmental havoc. An interagency study of
the restoration of the southern portion continues, which is focused on reducing the amount of Lake
Okeechobee water reaching the lagoon. In addition, a number of agencies monitor the lagoon for turbidity,
chemical contamination, and saline levels. The refuge staff helps state agencies monitor public use of
these waters. This cooperation enhances wildlife protection along refuge shores. See Chapter III for a
discussion on water quality in the lagoon and surrounding waters.
Partners-In-Flight Program
Diminishing numbers of migratory birds (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 a member of the Partners-In-Flight Program, which
includes coordination among federal, state, and non-governmental agencies; industry; and
conservation groups to promote research, land protection, and education about migratory birds. The
refuge is part of 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 migratory birds have been recorded passing through the South Florida
Ecosystem. More than 129 bird species migrate to the 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. This was done to stimulate a coordinated effort by federal, state, and private agencies
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to develop and implement comprehensive and integrated approaches for managing selected species.
The South Florida Ecosystem supports many of these species (Appendix IV).
The refuge=s mangroves and sand pine scrub provide important feeding and resting areas for
neotropical migratory birds, including the common yellowthroat (Geothlypis trichas), Cape May warbler
(Dendroica tigrina), blackpoll warbler (Dendroica striata), Connecticut warbler (Oporornis agilis),
yellow-billed cuckoo (Coccyzus americanus), and black-whiskered vireo (Vireo altiloquus). (Roberts
and Tamborski 1993; Rare and Endangered Biota of Florida 1996). In 2006, Hobe Sound Refuge
was made a part of the South Florida Birding Trail.
National Shorebird Conservation Plan
The refuge is in the Southeastern Coastal Plains/Caribbean Region, one of twelve regions in the U.S.
Shorebird Conservation Plan. For some species of shorebirds designated as high priority in the
Florida Peninsula, the refuge provides feeding and resting areas, as well as nesting habitat during
migration (Figure 7). For example, the endangered piping plover, uncommonly seen on the refuge,
uses it as a stopover site during fall and spring migration. Although the refuge is not designated as a
strategic migrational site by the Western Hemisphere Shorebird Reserve Network, the refuge
contributes survey data to the network.
Figure 7. High priority bird species abundance and seasonal use, Hobe Sound National
Wildlife Refuge
High Priority Species*
Relative Importance of
Southern Coastal Plain**
Abundance and
Seasonal Use of Refuge
Piping Plover B, M, W Uncommon, Spring, Fall, Winter
American Oystercatcher B, W Occasional, Winter
Wilson=s Plover B, W
Uncommon, Winter
Common, Spring, Summer, Fall
Buff-breasted Sandpiper M Not Observed
Marbled Godwit M, W Rare
Solitary Sandpiper M Not Observed
Stilt Sandpiper M, W Not Observed
Semi-palmated Sandpiper M Observed
Short-billed Dowitcher M, W Common, Winter
*Categories Ia and Ib, Highest and High Priority Species, Subtropical Florida and Peninsular Florida Partners-in-Flight
Bird Conservation Plans: Section 2: Avifaunal Analysis.
**Brown, S., C. Hickey, and B. Harrington (eds.). 2000. United States Shorebird Conservation Plan. Manomet, MA
Manomet Center for Conservation Sciences. 60p.
B=Breeding; M=Migrating; W=Wintering.
B,M,W=High concentrations, region extremely important to the species relative to the majority of the other regions.
Historically, the state-listed least tern and the Wilson=s plover have traditionally used the Jupiter
Island Tract for nesting. The refuge is the southernmost natural area remaining along the eastern
Hobe Sound National Wildlife Refuge 15
Atlantic coast where these birds could successfully nest. However, the loss of the above high tide
beach front and vegetation encroachment on the backdune have significantly reduced potential
nesting habitat. As a consequence, both species have declined in numbers on the refuge. To
exacerbate the plight of these species, some of the best remaining habitat is subject to extensive use
by beachgoers, which causes disturbance during the nesting period. With significant effort and
funding directed toward providing adequate nesting conditions and reducing human disturbance, it is
believed that the refuge could make an important contribution toward population increases.
North American Waterbird Conservation Plan
The Waterbird Conservation for the Americas initiative was launched in 1998, to provide a
continental framework and guide for conserving waterbirds of North America, Central America,
and the Caribbean. A product of the initiative is the North American Waterbird Conservation Plan
(James A. Kushlan et. al., 2002). The plan provides for the conservation and management of
210 species of waterbirds, including seabirds, coastal waterbirds, wading birds, and marsh birds.
The refuge contributes to the implementation of this plan by providing potential habitat for the
little blue heron, tricolored heron, reddish egret, white ibis, and wood stork.
Atlantic Coast Joint Venture and Florida Waterfowl Focus Areas
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.
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 waterfowl populations to 1970s= levels 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. Hobe Sound National Wildlife Refuge is part of the Atlantic Coast Joint
Venture. Additionally, the northern end of the Jupiter Island Tract of the refuge lies proximate to
Upper St. Johns and Adjacent Coast Focus Area, a waterfowl focus area delineated by the State of
Florida. Contained within this Focus Area is the Indian River Lagoon/Intracoastal Waterway, which is
considered an important resource for wintering waterfowl in Florida. The lagoon provides habitat for
waterfowl, such as green-winged teal, mottled duck, mallard, northern pintail, American wigeon, ring-necked
duck, and lesser scaup. While the refuge does not have jurisdiction over the Indian River
Lagoon, collaboration with federal and state agencies to improve and maintain the quality of its habitat
contributes toward meeting the goals of the North American Waterfowl Management Plan.
National Bird Conservation Initiative
The National Bird Conservation Initiative is a vision for the future of bird conservation in North
America. In the United States, this initiative evolved out of recognition among conservationists of the
value of coordinating and integrating the conservation planning, implementation, and evaluation
efforts to achieve a comprehensive, landscape-oriented approach to conservation.
Comprehensive 16 Conservation Plan
Out of this collaboration has come an over-arching framework for integrating the conservation of all
birds across all habitats under the National Waterfowl Management Plan, Partners-In-Flight Plan, U.S.
Shorebird Conservation Plan, and the National Waterbird Conservation Plan. Recently, the Atlantic
Coast Joint Venture Office, associated with the North American Waterfowl Management Plan, has
begun planning and implementing Aconservation of all birds across all habitats@ in several bird
conservation regions identified by the National Bird Conservation Initiative.
Hobe Sound Refuge is in the Peninsular Florida Bird Conservation Region. Mentioned as priority
species in the National Bird Conservation Initiative, for which Hobe Sound Refuge (or adjacent lands
and waters) provides potential habitat, are the Florida scrub jay, swallow-tailed kite, short-tailed hawk,
wood stork, brown pelican, limpkin, black skimmer, tern, black-whiskered vireo, lesser scaup, ring-necked
duck, mottled duck, short-billed dowitcher, piping plover, dunlin, and red knot, as well as a
variety of herons and egrets.
LEGAL AND POLICY GUIDANCE
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 some of the more important documents or Acts listed below. For a description of policies
and key legislation, see Appendix III.
 Executive Order 1312- Invasive Species (2/3/99)
 National Wildlife Refuge System Improvement Act of 1997
 National Wildlife Refuge System Administration Act of 1966 (16 U.S.C. 668dd-668ee)
 Refuge Recreation Act of 1962 (16 U.S.C. 460k-460k-4)
 Title 50 of the Code of Federal Regulations, Subchapters B and C
 Refuge Manual
 Fish and Wildlife Service Manual
 Endangered Species Act of 1973 (16 U.S.C. 1531-1543)
 Migratory Bird Conservation Act of 1929 (16 U.S.C. 715-715d)
 Migratory Bird Hunting and Conservation Stamp Act (16 U.S.C. 718-718h)
 Migratory Bird Treaty Act of 1918 (16 U.S.C. 703-712)
 National Environmental Policy Act of 1969 (PL 91-190, 42 U.S.C. 4321-4347)
 Bald Eagle Protection Act of 1940 (16 U.S.C. 668-668d)
 American Indian Religious Freedom Act (P.L. 95-341, [1978], 92 Stat. 42 U.S.C.1996)
 Antiquities Act (P.L. 59-209, approved 6/8/1906, 34 Stat. 225, 16 U.S.C. 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 U.S.C. 470 aa et seq.)
 Archaeological and Historic Preservation Act (P.L. 93-291 [1974, 88 Stat. 1974], amending
Reservoir Salvage Act, 16 U.S.C. 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 U.S.C. 3000-3013, 18 U.S.C. 1170)
 Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361-1421h)
 National Fire Plan
 Lacey Act of 1900 (16 U.S.C. 667E, 701; 18 U.S.C. 42-44; 62 Stat. 285), as amended
 Executive Order 11987 (1977) - Exotic Organisms
Hobe Sound National Wildlife Refuge 17
In addition to the Fish and Wildlife Service Manual, important policies influencing refuge planning and
management include:
 Compatibility Policy (2002);
 Biological Integrity, Diversity, and Environmental Health Policy (2001); and
 Draft Land Acquisition Planning Policy (2001).
A vision document entitled AFulfilling the Promise@ now guides the National Wildlife Refuge System
and was used in the development of this comprehensive conservation plan. The vision document
states the following beliefs of the Fish and Wildlife Service:
 Refuges are places where wildlife comes first;
 Refuges are anchors for biodiversity and ecosystem-level conservation and the system is a
leader in wilderness preservation;
 Lands and waters of the system are biologically healthy and secure from outside threats;
 The Refuge System is a national and international leader in habitat management and a center
for excellence where the best science and technology are used for wildlife conservation;
 Strategically located lands and waters are added to the Refuge System until, in partnership
with others, it represents America=s diverse ecosystems and sustains the nation=s fish,
wildlife, and plant resources;
 The Refuge System is a model and demonstration area for habitat management, which fosters
broad participation in natural resource stewardship.
Comprehensive 18 Conservation Plan
Hobe Sound National Wildlife Refuge 19
II. Planning Issues and Opportunities
“…and perhaps the most remarkable part of their generosity was the raising of money
to purchases the mile of land just north of the southern end of Jupiter Island for The
Nature Conservancy and later to the Interior Department of five hundred acres on the
north end of the island in 1976.”
Permelia Reed
INTRODUCTION
Creating a vision of the future for the Hobe Sound National Wildlife Refuge came easily for some and
more cautiously for others. Although comprehensive conservation planning officially began in 1998,
this was preceded by visioning in the implementing legislation and the establishment authority of the
refuge in 1969. Honoring this legacy and early in the development of this plan, the pre-planning team,
made up of Fish and Wildlife Service personnel, identified issues and opportunities that were likely to
be associated with future management of the refuge. This list was derived from team knowledge,
meetings with intergovernmental partners, a public scoping meeting, and written comments submitted
by the public. This document allows all who participated in the process, as well as those who are
newcomers to the process, to gaze once again into the future and glimpse what the refuge can and
should be.
IDENTIFYING THE ISSUES
The public scoping meeting, held on August 18, 1998, at the Hobe Sound Civic Center, provided the
public with an opportunity to assist the refuge in identifying issues and concerns. Approximately 70
people were in attendance at the meeting. Following a 15-minute presentation concerning the refuge,
attendees 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. While some of the comments are significant to the future of the refuge, many are not
within its sole jurisdiction and others are completely outside its jurisdiction.
Responses to comment sheets, distributed at the public scoping meeting and at the refuge, and
handwritten letters on postcards provided information on issues and concerns of importance to the
public. The comment packet and a summary of the comments can be found in Appendix V.
The excitement and enthusiasm of the participants cannot be easily imparted. In some cases, good
suggestions have already been implemented. The alternatives considered for managing the refuge
incorporated many of these issues and concerns.
The issues of main concern to the public were categorized into wildlife habitat management,
recreation, education and public awareness, partnerships, historical resources, and administration.
WILDLIFE HABITAT MANAGEMENT
 Restore and manage species and the habitats they occupy so that the native biodiversity of
the refuge is enhanced. Many citizens expressed a desire for biological surveys and
inventories to monitor plant and animal species on the refuge, especially those listed as
Comprehensive 20 Conservation Plan
threatened and endangered. A few attendees were particularly concerned with the
management of the least tern nesting colonies on the Jupiter Island Tract.
 Reduce and/or eliminate exotic species from the refuge. Most of the participants wanted the
Australian pines removed from the barrier island (to support sea turtle nesting) and from the
shoreline. They were also concerned about Brazilian pepper and Old World climbing fern.
Some present wanted to see the refuge staff consider alternative control methods for invasive
species. A number of citizens wanted to see the areas of the refuge impacted with exotics
restored to their natural states by physically removing the exotics and replanting with natives.
A few expressed concern that only exotics be removed and the native plants be left alone, and
that aesthetics should be considered and large strands of dead trees removed. Some also
wanted to see an increased effort to remove exotic animals from the refuge.
 Address sea turtles by protecting, restoring, and managing their habitat through means such
as habitat acquisitions, limiting or eliminating lights (e.g., floodlights and street lights on North
Beach Road) during hatching season, and increasing law enforcement to prevent poaching.
Many people felt the refuge should help educate the local community about lights on the
beach during the sea turtle nesting season. A few disapproved of night-time turtle walks,
stating the turtles should be left alone while laying their eggs. Others wanted to see the
development of volunteer groups to protect hatchlings and help guide them to the water.
Others were concerned about the mammalian predation of sea turtle nests, and wanted to see
the predator population controlled. Still others wished to see an increased level of sea turtle
monitoring, and also habitat restoration and acquisition of additional habitat.
 Consider the use of prescribed burns to enhance habitat and manage fuel loads, especially
the sand pine scrub area on the mainland. Many people stated that the refuge has not
burned, either by prescribed burn or wildfire, for a number of years and would like to see a
prescribed burn implemented in the sand pine scrub to provide optimal scrub jay habitat, and
also to help the sand pines regenerate. Many citizens are concerned about the possibility of
catastrophic wildfire if the refuge does not actively reduce the fuel load by prescribed burns
and/or mechanical treatments.
 Expand refuge resources by acquiring adjacent land and the management authority of
offshore resources, possibly in conjunction with St. Lucie Inlet Preserve State Park. Some of
the citizens would like to see the refuge obtain the U.S. Coast Guard property near the refuge
boundary on the island and actively manage it for sea turtle habitat, control of exotics, and to
conduct other needed habitat management activities. A few suggested refuge management
should try to acquire management authority of offshore resources, possibly in conjunction with
St. Lucie Inlet Preserve State Park. Others would like to see the Service enforce boating use
and speeds and provide more manatee protection.
PUBLIC USE: RECREATION
 Enhance the public=s use of the beach by providing more public access and more
amenities and by maintaining boat access to Peck Lake. Many people requested more
public access to the refuge beach, in particular, the Peck Lake area. These citizens
would like the Peck Lake access to remain open to boaters and beach users, and the
trails maintained leading from the lake to the ocean. A wildlife observation platform at
Peck Lake was requested. A few wanted a section of the beach designated for surfers,
while others asked that a section be allotted for clothing-optional sunbathing. The crowd
seemed to be split on the issue of personal watercraftBsome requested that it be
Hobe Sound National Wildlife Refuge 21
outlawed, while others did not want restrictions on any vessel. Several citizens requested
upgrades to the beach facilities. Many would like a permanent, state-of-the-art bathroom
facility and outside showers. A few asked for picnic pavilions and still others expres sed
concern about impacts of increasing public use at the beach. The latter group expressed
that they like the remoteness of the beach, and do not want to see the parking lot
expanded. One group requested that attaining a beach pass be made easier.
 Allow boating, surf fishing, and more fishing access on the mainland and consider installing a
dock and inlets at Peck Lake. Many in attendance requested more fishing access to the
Indian River Lagoon along the mainland. Some requested a dock at Peck Lake, while others
opposed such additions and any plans for a future walkway constructed from the Jupiter
narrows to the refuge. A few asked that no anchoring restrictions be imposed.
 Keep the refuge cleaner and expand the ways the public could assist in trash removal efforts.
A number of citizens expressed concern about litter on the refuge. Some suggested a
volunteer task force, or perhaps the local boys scout troop could perform regular clean-ups.
Others asked that more trash receptacles be placed on the refuge. Several suggested posting
ATRASH IN - TRASH OUT@ signs, while others mentioned providing trash bags so people
could pick up trash as they enjoy the refuge. Some think the refuge should provide plastic
bags and scoops for pet owners. A few mentioned that the Center for Marine Conservation
(now called The Ocean Conservancy) is performing a 5-year litter survey, and think that the
refuge should be added to this survey.
 Support recreational and educational uses, as long as commercial recreation is not allowed.
Hunting and fishing must have a minimal impact on the environment. Many of those present
did not want to see commercialization on the refuge. Some were also concerned about what
possible negative impacts hunting and fishing would have on the refuge and would like to see
such activities kept to an absolute minimum. (Because of the proximity of refuge lands to
people, hunting is not allowed.)
 Make the refuge accessible for only those human uses that are compatible with the refuge=s
native wildlife. Some stated concerns about overuse of the refuge. They enjoy the quietness
of the refuge and do not want to see it spoiled. They do not want to see night access or
camping on the refuge. They want refuge management to quantify visitor impacts and
determine the refuge=s human carrying capacity. Many feel dogs should be leashed at all
times, while others feel dogs need only be under control but not necessarily leashed. Other
citizens requested that more of the refuge be open to visitors in appropriate areas.
 Support hiking by lengthening existing nature trails, installing more trails in other parts of the
refuge, and installing more signs that identify plants and describe the natural area.
 Many stated the need for more than one nature trail. They would also like the trails to be
longer and to have more interpretive signs identifying significant plants and facts about the
surroundings. Some stated that the nature trails are excellent as they are now.
 Preserve current uses like shelling and expand to include a permanent restroom facility, high
water markers to record storm surges, and better access for canoes. A few people stated a
request for better canoe and kayak access to the island. Some would like high water markers
to record past, present, and future storm surges.
Comprehensive 22 Conservation Plan
 Maintain the refuge=s beach tract and renourish the beach. Some stated the need for beach
renourishment in order to stabilize the refuge beach and prevent erosion caused in large part
by the St. Lucie Inlet. In kind, prevent Abreak through@ caused by storm surges at the Peck
Lake area. A few opposed beach renourishment. Others asked that the mosquito
impoundments and spoil sites be restored.
PUBLIC USE: EDUCATION AND PUBLIC AWARENESS
 Enhance environmental education by increasing the amount of programs that target population
niches such as: children and their families, schools, senior citizens, youth camps, and adult
education classes. Many would like to see enhanced public education. They suggested
conservation summits for children and families to help children learn about the environment.
Others would like to see public education trails developed specifically for children. Some
suggested special programs in middle schools for students who might be interested in
volunteering at the refuge and given the rank of AJunior Ranger.@ Some citizens requested
more education to address problems rather than levying fines (e.g., a kiosk about what litter
does to the environment instead of fining offenders). A few stated that the current Nature
Center is doing an excellent job.
 Increase the number of interpreters, provide more printed interpretive information, increase the
number of trails used for interpretation events, and expand to provide more events during the
evenings and on weekends. Many citizens requested more interpretive signs on the nature
trail and headquarters area. Several in attendance requested evening and weekend programs
to accommodate those who work during the weekdays. Some also wanted an interpretive trail
through the mangroves near the beach parking lot. Many also stated the need for additional
turtle walks to accommodate more people.
 Increase publicity by creating a management plan, which advertises the refuge through all
media formats. Create more refuge pamphlets and add directional signs to the refuge. Some
stated that the refuge needs to be more visible in the community by adding links to its Internet
web page, and the interpretive programs should be more heavily advertised. Others
expressed maintenance and restoration work should be advertised so the public would be
aware of and support such activities. Also, many feel the public should be made aware of the
various passes available to the refuge.
PARTNERSHIPS
 Create cooperative relationships with other agencies and the community for joint projects.
 A few at the meeting stated local environmental organizations need continuity of management
plans. Some want to see the restriction of jet skis by joint agency coordination, while others
say there should be no restriction of any vessel. A few citizens suggested the refuge cultivate
partnerships with volunteers, inmates, and local civic groups.
HISTORICAL RESOURCES
 Conduct archaeological surveys prior to beach renourishment, preserve the shell mounds on
the mainland, and devote a section of the local library to historical information about the
refuge. Some at the meeting suggested that the ancient shell mounds on the refuge need to
be preserved. Others requested a library devoted to local history be started at the refuge. A
few people expressed a desire for archaeological surveys on the refuge, especially prior to
Hobe Sound National Wildlife Refuge 23
beach renourishment projects. Still others requested the restoration of the sand mine on the
mainland section of the refuge (near the intersection of U.S. Highway 1 and Dixie Highway).
ADMINISTRATION
 Increase the number of staff (all classifications) and volunteers to provide more recreational
opportunities, wildlife habitat management, educational programs, and eradication of exotics.
Some stated concerns that the refuge needed a larger staff to efficiently care for all the needs
of the refuge and its visitors. Others requested Aproactive@ refuge management, while others
felt that the refuge manager should keep accurate written records to provide continuity for
successive managers to address the unique characteristics of the refuge.
 Improve refuge headquarters= accessibility by improving existing ramps, providing more signs
at refuge headquarters, and providing directional signs on Interstate 95 and the Florida
Turnpike. Many requested that more signs be posted on local roadways to make locating the
refuge easier. Others asked that the refuge be maintained as accessible as possible, and
requested that the existing handicap ramps be improved. Some present would like the fire
lanes posted as access to the Intracoastal Waterway for fisherman. Still others requested that
the parking lots not be expanded, but the refuge should supply transportation from remote
areas as needed. Several people stated that the refuge should create partnerships with other
local agencies and provide connecting sidewalks/bike paths/roller blade paths to get to the
refuge.
 Maintain safety of refuge users and the environment by implementing such measures as
providing lighting at the headquarters parking lot, installing an emergency phone at
headquarters and fee booth, developing a plan for an oil spill or hazardous waste response,
and developing an action plan to remove safety hazards (e.g., abandoned wells and
structures). There was concern about the safety hazard posed by derelict wells and other
abandoned structures on the refuge. Some would like to see the refuge implement a
hazardous waste emergency response plan.
 Restrict any land swaps of refuge lands because the land was provided for the refuge and not
for other uses. Consider purchasing land adjacent to the refuge to create green ways. Many
people felt strongly about the issue of the refuge considering land swaps with local
landowners. Most felt the current refuge property needs to remain undeveloped and managed
for its original purpose of wildlife habitat. Others would like to see the refuge acquire more
land surrounding its boundary to create buffer zones and green ways between it and
developed lands.
 Upgrade the refuge=s public facilities, including the headquarters building and visitor center.
The new building must be constructed in a manner that maintains the look of the refuge. If
new buildings are constructed, they should be an integral part of the land. Many people
commented on the need to upgrade the refuge=s facilities, but they also urged caution about
overbuilding. They stressed that a new headquarters building should blend well with the
surroundings and be landscaped with aesthetics in mind. A few citizens stated that the only
necessary development needed on the refuge is to expand the beach parking lot.
Comprehensive 24 Conservation Plan
SIGNIFICANT REFUGE ISSUES
Utilizing the issues identified by the public and by Service staff, the core planning team identified
those issues most significant to the refuge over the 15-year life of the comprehensive conservation
plan. These issues include visitor use, resource protection, and administration.
VISITOR USE
As with so many other refuges in the system, Hobe Sound Refuge is faced with a growing demand for
visitor use. Historically, the refuge has maintained a Afavorable@ balance between wildlife protection
and visitor use. However, as the human population in south Florida increases, so does the demand
for outdoor recreation; further stressing its natural communities. During the public scoping meeting,
many people identified a desire for improved facilities, better access, and additional recreational
activities on the refuge. Many areas that could serve as new trails require access along North Beach
Road on Jupiter Island. This will present difficulty for some private property owners who are
concerned about the traffic flow along this narrow access road, which serves as the only vehicular
access for the refuge to its 735 acres on Jupiter Island.
Although the refuge will not compromise the protection of the ecosystem, numerous opportunities
exist to enhance the visitor experience without impacting the resources. More opportunities for visitor
use will be available upon completion of the new refuge headquarters and visitor center. The facility
will include an environmental learning center with interpretive displays and a gift shop.
RESOURCE PROTECTION
Invasive Species
“Today, the island is almost completely masked out by a seemingly solid, high hedge of
Casuarinas. These trees were not planted until 1916; prior to that time one could have
viewed the island in an unbroken sweep.”
Joseph V. Reed
Many hazards threaten the integrity of the delicate South Florida Ecosystem, and perhaps none are as
ominous as those imposed by invasive exotic plants. Within the refuge, these invaders threaten to
displace two of three natural communities. The Atlantic Coastal Dune, which supports some of the
most productive sea turtle nesting areas in the nation, is under constant threat of colonization by
Australian pines. This species is very salt tolerant and can rapidly overtake the foredune. The tall
bushy trees shade the dune eliminating conditions favorable for plants that stabilize the dune.
Without a vigorous control effort by refuge staff and/or contractors, the coastal dune community would
certainly be over-run by this and other aggressive species such as Brazilian pepper, beach naupaka,
mahoe, periwinkle, rosary pea, and snake plant. The unique hammock communities are very
susceptible to being overrun by invasive plants because of their locations, moist microclimate,
relatively small sizes, and history of little attention.
Speed Boats and Wakes
A third refuge plant community is also at risk of severe degradation. The mangrove wetland
community found lining the shores of the Indian River Lagoon is receding along much of its range on
the refuge. High energy wakes spawned from increased boat traffic continually bombard the eroding
shoreline. These waves prevent red mangrove propagules from establishing in the soil. Erosion is
Hobe Sound National Wildlife Refuge 25
compounded by the increasing boat traffic in the Intracoastal Waterway, personal watercraft intrusion
into shallow waters, the absence of slow speed zones along the refuge, and a lack of enforcement of
slow speed zones outside main channels.
The refuge contains a significant acreage of coastal strand and tidal swamp habitats. These habitats
will be, and probably already are, affected by ongoing sea-level rise. Predicted rises, based on the
research of the Intergovernmental Panel on Climate Change, suggest that a 5 cm sea-level rise in 50
years would exact consequences for the resources, purposes, and objectives of this refuge that would
elevate issues, such as boat wakes, to even greater significance.
Within the last few years, increasing evidence of the importance of the Indian River to sea turtles has
been documented. Juvenile sea turtles, primarily green sea turtles, utilize the Indian River for early
development and are impacted by speeding boats (Bresette et al., 2002).
Although Florida manatees are found at the shores of the refuge property, they live in state
jurisdictional waters. However, protection of this species is considered a mandate of the Fish and
Wildlife Service. Threats of population declines stem from degraded habitat, specifically seagrass
beds, vessel collisions, and natural causes such as red tide. Although the state has implemented the
majority of protective measures to address watercraft-related mortality, the enforcement of Aspeed
zones@ is addressed at all levelsB-federal, state, and local. Service law enforcement officers, who
either work at refuges or are assigned to special details, also enforce the manatee protection zones.
Any attempts to minimize effects of boat traffic in the Indian River Lagoon would assist both the
recovery of mangrove wetlands, manatee populations, and juvenile sea turtles..
Fire
Coastal sand pine scrub has evolved as a fire-dependent community over the last 100,000 years.
Only in recent history have humans occupied the landscape and altered the natural fire regime by
standardizing the practice of fire suppression. Though seemingly noble, these intentions have served
to not only alter the natural composition of the community, but have also increased the likelihood of
catastrophic wildfire. As the trees age, fallen debris (e.g., needles, leaves, and branches) accumulate
on the forest floor. This thick carpet is an extremely combustible fuel that, when dry, ignites quickly
and burns rapidly.
Attempts to undertake prescribed burning on this landscape have proven extremely difficult due to the
very restrictive weather conditions associated with the refuge=s proximity to a federal highway.
Mechanical treatment of this sand pine scrub requires evaluation to determine whether it can serve as
an adequate substitute for fire unless future prescription will allow closure of the federal highway.
Refuge Boundaries
Today, the refuge exists largely as a compilation of disjunct lots and blocks of land. Much of the
property is contiguous, however, the north end of the island and the south end of the mainland appear
as a mosaic of public and private lands. Many undeveloped private lots are dispersed throughout the
refuge. These in-holdings, some greatly infested with exotic plants, act as seed sources that spread
to neighboring natural communities. Consolidating the refuge would provide a contiguous wildlife
corridor while preserving the integrity of the natural system. It would enable better and more efficient
management activities. These lands have been identified and could be acquired through a variety of
means including purchase at fair market value, cooperative agreements, or donations.
Comprehensive 26 Conservation Plan
Beach Erosion
Since the completion of the St. Lucie Inlet in the late 19th Century, the shoreline south of it has been rapidly
eroding. Without our intervention, the northern end of the barrier island could conceivably erode through to
the Indian River Lagoon as it did in 1963. Among the more obvious problems associated with this scenario
is the loss of one of the most productive sea turtle nesting beaches in Florida.
Beach renourishment and revegetation of the foredune have been used as temporary remedies.
Significant evaluation of beach renourishment on sea turtle nesting activities on Jupiter Island has shown
thus far that beach renourishment, if conducted properly and using a highly beach compatible sand source,
can provide suitable sea turtle nesting habitat and has little effect on the ability of hatchlings to emerge from
the nest. Over the years, refinements in beach renourishment techniques have resulted in improved grain
size selection, sand borrow site locations, escarpment prevention, and improved placement to avoid and
minimize impacts to hard bottom reef communities. Significant evaluation of beach renourishment on sea
turtle nesting activities on Jupiter Island has shown thus far that beach renourishment is necessary to
provide these turtles with the habitat necessary to sustain their populations, and has little effect on the
ability of hatchlings to emerge from the nest. The biological factor that has the greatest effect on
reproductive success is depredation by raccoons and armadillos (Ecological Associates, Inc.).
Many municipalities and property owners have chosen to construct concrete walls along the dune's edge to
protect their communities and homes from erosion. Although these walls (known as beach armourment)
protect the properties, they exacerbate beach lossBhabitat, which is required by nesting and feeding
shorebirds and nesting sea turtles. While renourishment and replanting projects have helped slow the
erosion rate, neither provides a long-term solution to the problem. A comprehensive study is needed to
investigate possible alternatives that would protect the land and enhance wildlife habitat.
ADMINISTRATION
When established in 1969, Hobe Sound National Wildlife Refuge was one of only a handful of south
Florida refuges. A.R.M. Loxahatchee National Wildlife Refuge was given administration and oversight
of the refuge in the late 1970s. For several years, Hobe Sound was considered to be a refuge with
few issues and relatively little public use. Today, nearly 120,000 people visit the refuge annually.
Substantial improvements have been made to increase support for the refuge. Nevertheless, staffing
remains unchanged; budgets still compete with higher priority concerns; and the growing issues at
Hobe Sound Refuge are not adequately addressed. It was the consensus of the planning team that
the Service should evaluate whether to continue the current management structure, to cluster Hobe
Sound Refuge with another refuge that has similar resource issues, or to launch it as a separate
refuge.
Hobe Sound National Wildlife Refuge 27
III. Refuge Environment
"When the dredge came down the Indian River; he had no difficulty persuading the
dredge master (with permission from the War Department) to place the fill from the
dredge in his swamp-which there-upon became high and fertile land."
Permelia Reed
PHYSICAL ENVIRONMENT
CLIMATE
Located in southeast Florida, Hobe Sound National Wildlife Refuge is characterized by a subtropical
climate. Temperatures very rarely fall below freezing in the winter months and often reach mid- to
high-90s in the summer months of July, August, and September. Temperatures measured at the
Palm Beach International Airport weather station range from an average annual maximum of 83oF to a
minimum of 67oF (Winsberg 1990). The average January temperature is 65.1oF, and the average
August temperature is 81.8oF.
Specific weather data for the refuge is gathered from a fire weather station located at nearby
Jonathan Dickinson State Park. According to this data, the refuge receives an average of 50 inches
of rain per year, with most of it occurring from June through November.
During the wet season, thunderstorms that result from easterly trade winds and land-sea convection
patterns occur almost daily. Wet season rainfall follows a bimodal pattern with peaks during May-
June and September-October. Tropical storms and hurricanes also provide major contributions to wet
season rainfall with a high level of variability and a low level of predictability. During the dry season,
rainfall is governed by large-scale winter weather fronts that pass through the region approximately
every 2 weeks. High evapotransporation rates in south Florida roughly equal mean annual
precipitation (U.S. Army Corps of Engineers 2002).
AIR QUALITY
The existing air quality within Martin County is considered good, and the region meets current National
Ambient Air Quality Standards. This condition is not expected to change in the immediate future (U.S.
Army Corps of Engineers). Prescribed burning at the Jonathan Dickinson State Park temporarily
reduces air quality during certain times of the year.
NOISE/TRAFFIC
Noise at the headquarters area is influenced by traffic along U.S. Highway 1 moving at a speed limit of
55 mph. The noise levels are expected to gradually increase in the future, as this highway is presently
being widened. The populations of the surrounding municipalities of Hobe Sound, Stuart, Jupiter
Island, and Jupiter are increasing faster than the national average, resulting in an increase in
vehicular traffic.
Traffic noise is heard by visitors using trails, which hinders the outdoor experience somewhat. The
perception of traffic noise by wildlife is not well understood. However, more importantly than the traffic
Comprehensive 28 Conservation Plan
noise is the habitat dissection from U.S. Highway 1 through the sand pine scrub. This dissection
results in significant road kill on a routine basis as animals attempt to cross the highway. This also
results in difficulty in recruiting wildlife populations to the narrow strip of sand pine scrub land that is
bordered by the highway on one side and the Indian River Lagoon on the other side.
GEOLOGY AND SOILS
The refuge is comprised of two separate tracts of land bisected by the southerly portion of the Indian
River Lagoon. The beach tract is known as the Jupiter Island Tract and is composed of 735 acres of
a barrier island. The upland tract is west of the beach on a 300-acre mainland site, referred to as the
Mainland Tract.
According to the reference book, ASoil Survey of Martin County, 1989 USDA@ the refuge includes two
broad soil groups: 1) soils of the sand ridges and coastal islands; and 2) soils of the tidal swamps.
Soils of the sand ridges and coastal islands are composed of the soil complex known as Palm Beach-
Canaveral-Beaches. Tidal swamp soils allow wetland vegetation to flourish and appear as isolated
pockets on both the Mainland Tract and the Jupiter Island Tract. Seventeen different soil types exist
throughout the refuge resulting in a wide variety of sub-habitats within the ecosystem.
Mainland Tract - Geology
The Mainland Tract is situated on a relic dune rising as high as 50 feet above sea level. This ancient
dune is part of the Atlantic Coastal Ridge, formed during the Pleistocene (about 10,000 years ago)
and Holocene epochs. Elevation in nearby Jonathan Dickinson State Park ranges from sea level to
92 feet. This ancient sand dune is characterized by siliceous sandy, well-drained soils. The scrub
ecosystem is probably the oldest plant community in Florida. The scrub habitats in southern Florida
became established in the Pleistocene and sand ridges, which were deposited originally as coastal
dunes formed by two processes: beach ridge deposition from changing sea levels and wind blown
deposition (Austin 1999).
Mainland Tract - Soils
Soils on the Mainland Tract of the refuge are predominately associated with those of the southern
section of the Atlantic Coastal Ridge. According to Austin (1999), AThe sands on the scrub ridges are
fine and white near the surface. They are quartzose with little calcareous or organic content and are
locally known as Asugar sand.@ Geologists believe that their Asugary@ appearance results from
having been heavily leached of calcareous and organic materials. Technically, the sands are called
St. Lucie Fine Sand, the most abundant phase, or Lakewood Fine Sand. St. Lucie sands range from
white to gray in profile and may reach 50 feet in depth. Lakewood may be almost as deep but only the
top 24 to 36 inches are white; below there is a yellow subsoil. As with most soils in the Mainland
Tract, they are moderately to extremely well drained and permeable and are deep sand of marine
origin. They are slightly to strongly acidic, are of low natural fertility, and make relatively poor
agricultural land (Fernald 1989).
Jupiter Island Tract - Geology
The 735-acre Jupiter Island Tract has very little elevation ranging from sea level to 12 feet. The entire
barrier island was formed through the deposition of marine sediment caused by fluctuating sea levels.
The barrier island beach is subject to accretion and erosion. The erosion process is partly attributed
to the nearby St. Lucie Inlet, with water flowing to/from the Indian River Lagoon and inhibiting the
littoral drift of sand in a southerly direction. The Atlantic Ocean side of the barrier island is a high-
Hobe Sound National Wildlife Refuge 29
energy shoreline. The erosion potential along this section of shoreline is greater than at many other
locations of Florida because the continental shelf narrows continuously from northern Florida to
southern Florida. Once south of Jupiter Inlet, the effects of a narrower shelf are offset partly by wave
sheltering by the Bahama Banks offshore. Jupiter Island lacks this sheltering, so its sediment
transport and erosion potential are relatively higher. The sand deposited in the inlet is periodically
dredged and pumped onto the beach. In March 1963, a severe storm caused the Atlantic Ocean to
break through a narrow portion of the island. This natural inlet created near Peck Lake was usable for
navigation. In fact, due to its more gentle currents, it was actually preferred over the nearby man-made
St. Lucie Inlet. However, due to increased shoaling in Peck Lake and severe degradation to
adjacent southerly beaches, the inlet was closed by the Army Corps of Engineers in August 1964.
Jupiter Island Tract - Soils
Five soil types comprise the Jupiter Island portion of the refuge. These soils, known as Palm Beach-
Canaveral-Beaches soils complex, are described as nearly level to sloping, well-drained soils that are
sandy throughout and contain shell fragments. Soils of the tidal swamps are composed of the soil
complex known as Bessie-Okeelanta Varient-Terra Ceia Varient. These are described as Anearly
level, very poorly drained organic soils; some have a clayey layer in the substratum, some have sandy
substratum, and some have more than 50 inches of organic material. Isolated pockets of tidal swamp
soils exist on the Jupiter Island Tract as well as in small areas of the Mainland Tract.
HYDROLOGY
The majority of the 300 acres of the Mainland Tract of Hobe Sound Refuge is atop a relic dune of the
Atlantic Coastal Ridge. This tract is composed of very permeable soils of the Paola series. The water
table averages greater than 6 feet in depth. Bordered on the east by the Indian River Lagoon, these
soils readily leach and drain into the brackish water of the lagoon. The extreme permeability of the
soils allows only those plant species adapted to very dry conditions to exist. Several low-lying, mostly
freshwater wetlands transverse the refuge draining from U.S. Highway 1 into the lagoon. These
wetlands are subject to saltwater intrusion affected by tidal cycles.
The 735-acre Jupiter Island portion of the refuge has lithology (i.e., physical character and
composition of sediment or rock) similar to that of the Mainland Tract with two major aquifers, a
shallow (non-artesian) surficial aquifer approximately 150 feet below the land surface and the
Floridian (artesian) aquifer approximately 600 to 1,500 feet below the land surface. It is the surficial
aquifer that supplies most of the potable water in Martin County, and slightly more than half of the
water to Jupiter Island residents. Much of the rain that falls on Jupiter Island infiltrates the shallow
unconfined aquifer, while the rest runs off or remains on the surface where it adds to the Indian River
Lagoon system, the mangrove community, and the tidal creeks on the refuge (St. Lucie Inlet Preserve
State Park Management Plan 2002). Three mosquito impoundments exist on the Island Tract, but
are, for the most part, filled in or choked off by exotic plants.
WATER QUALITY
Human activities have degraded water quality in large areas of south Florida during the last century.
Water in urban and agricultural canals commonly has high concentrations of nutrients and toxic
compounds compared to water in marshes that are remote from canals. Drainage of nutrients and
contaminants from urban and agricultural lands has degraded lakes, streams, canals, and estuaries of
the region (McPherson and Halley 1997). In addition, discharge of nutrient-laden sewage and storm
water runoff into canals also carries bacteria, viruses, oil and grease, toxic metals, and pesticides.
The urban canal water discharges into coastal waters or enters the groundwater system and the
Comprehensive 30 Conservation Plan
public water supply (Klein et. al., 1975). The alteration of freshwater flows to the estuaries along the
coast of Florida has reduced water quality of these habitats. Diseased fish and an increase in
stranded and dying dolphins have been attributed to a decrease in water quality of the lagoon
(Harbor Branch Oceanographic Institute 2002). A fish kill in August 2002, along the refuge beach of
Jupiter Island, was believed to be attributable to discharges of water from Lake Okeechobee and
associated canals (Port St. Lucie News, August 10, 2002).
The County Coalition for Responsible Management of Lake Okeechobee and St. Lucie and
Caloosahatchee Estuaries and Lake Worth Lagoon is an association of nine counties (Lee, Hendry,
Glades, Highlands, Palm Beach, Martin, St. Lucie, Okeechobee, and Osceola) that is influenced by Lake
Okeechobee and its water management. The coalition represents the interests of approximately 2.2 million
people in the 9-county area. The coalition is extremely concerned with issues associated with Lake
Okeechobee discharges that impact the Indian River Lagoon and the St. Lucie Estuary, as well as other
important water bodies and the natural resources that are sustained by them.
Fertilizers are widely used in south Florida to maintain high levels of agricultural productivity. From
July 1, 1990, through June 30, 1991, fertilizers sold in south Florida contained 127,000 metric tons
(140,000 tons) of inorganic nitrogen and 50,800 metric tons (56,000 tons) of phosphate (McPherson
and Halley 1997). Nutrient loading from the Everglades Agricultural Area and urban areas has
significantly increased nutrient concentrations, particularly phosphorus, in the South Florida
Ecosystem (Stober et. al., 1996).
Herbicides, such as atrazine, bromocil, simazine, 2-4-D, and diuron, which have the highest rates of
application, are among the most frequently detected pesticides in Florida's surface waters. By far the
most frequently detected insecticides in surface waters are the chlorinated hydrocarbons that are no
longer used in the state, such as DDD, DDE, DDT, dieldrin, and heptachlor (Shahane 1994). These
are also the most frequently detected pesticides in bottom sediments (Shahane 1994). For the St.
Lucie River Estuary, which is north of the refuge, the pesticides ametryn, atrazine, hexazinone,
bromacil, norflurazon, and simazine are in the top ten as far as the number of times detected in the
estuary from 1992 to 1997 (Florida Department of Environmental Protection 1998).
BIOLOGICAL ENVIRONMENT
The refuge provides habitat and protection for approximately 40 plant and animal species listed as
either threatened or endangered by federal and state agencies (Appendix IV). Nevertheless, the
refuge has very limited information about its resources, since they have not been adequately
described or surveyed. Much work needs to be done to describe, both qualitatively and quantitatively,
the habitats and resources of the refuge.
General descriptions of the biological resources of the 300-acre Mainland Tract, the Indian River
Lagoon, and the 735-acre Jupiter Island Tract are provided.
MAINLAND TRACT
The primary vegetation classes on the Mainland Tract consist mainly of sand pine scrub, wetland,
mangrove, and hammock habitats (Figure 8).
Hobe Sound National Wildlife Refuge 31
Figure 8. Vegetation on mainland tract, Hobe Sound national Wildlife Refuge
Comprehensive 32 Conservation Plan
Figure 9. General distribution of scrub in Florida, adapted from Davis, 1967
Hobe Sound National Wildlife Refuge 33
Sand Pine Scrub
Distribution and Characteristics. Compared with other ecosystems in Florida, scrub habitat is scattered
across the landscape with concentrations along coastal and central ridges in peninsular Florida (Figure 9). In
the panhandle, scrub is restricted to a narrow strip along the Gulf coast and on barrier islands. Scrub is
frequently cited as Florida=s most distinct ecosystem; physiognomy and composition are quite distinct from
surrounding habitats and between 40-60 percent of scrub species are considered to be endemic. Scrub
habitat, a xeric vegetative community, contains a biological treasure of plants and animals adapted to
life on scattered ridges of sand. There are more endangered or potentially endangered wildlife
species located here than in any other habitat in Florida. The ancient origins of these sand dune
communities date back to the Pliocene savannahs and provide a relic example of an extremely old
and formerly extensive ecosystem (Deyrup and Eisner 1993). Of the original distribution of Florida
scrub ecosystem, only 10 percent remains, the rest replaced by citrus groves and housing
developments.
Currently, the highest, oldest, and driest areas of the refuge are composed primarily of mature sand
pine trees (Pinus clausa); hence the habitat is referred to as a sand pine scrub habitat. The scrub
midstory consists of dense growing xeric plants such as Chapman=s, myrtle, and sand live oak;
varnish leaf; rosemary; gopher apple; and saw palmetto. The scrub understory is also relatively
closed, supporting many species of lichens, grasses, and forbs which cover the scrub floor (Fernald
1989). At lower elevations, a more mesic environment supports slash pine and dense understory
growth of saw palmetto, coin vine, gumbo limbo, Spanish lime, staggerbush, and many forbs
(Richardson 1977).
Fire Ecology. Sand pine cones require stress, like fire, to open and release seed, while shrubby
species like scrub oaks quickly regenerate from stored energy in their roots. Shade intolerant species
like scrub mints will respond to the increased duration and intensity of light from seed sources.
Although the first prescribed burn on the refuge took place in January 2002, half of the sand pine
scrub community is between 45 and 65 years old. This age roughly marks late-middle senescence of
the scrub community. Some studies have concluded that the sand pine scrub community should be
managed on a 15- to 25-year rotation, with many native species becoming absent after 20 years
(Roberts and Cox 2000). Sand pines become sexually mature 15 to 17 years after their seeds are
released by fire. Until a prescribed fire that jumped from Jonathan Dickinson State Park over to the
refuge in 2006, the age of the youngest stand on the refuge was over 30 years. Those trees were
found in the area setback by wildfire in 1971. Several new sand pines have regenerated without fire
following mechanical treatment, which is a disturbance that mows or chops the scrub habitat, opening
the canopy to allow sunlight to penetrate. Sand temperatures reached sufficient intensity to release
pine seeds. Research is necessary to evaluate mechanical versus prescribed fire as methods to
rejuvenate this habitat. Attempts at creating bare ground through prescribed fire have met with mixed
success (Greenberg 2003). Bare ground and open areas in the scrub are necessary to attract and
maintain other species, such as the scrub jay.
Wildlife. The most common mammals are the gray fox, bobcat, white-tailed deer, raccoon, Virginia
opossum, striped and eastern spotted skunk, eastern mole, least shrew, mice species, gray squirrel,
and perhaps up to five bat species.
The birds of sand pine scrub habitat are the Florida scrub jay, northern mockingbird, northern
cardinal, blue jay, Carolina wren, chuck-will=s widow, mourning dove, white-eyed vireo, eastern
towhee, osprey, great horned and eastern screech owls, red-bellied and downy woodpeckers, great-crested
flycatchers, and northern bob-white. In its position in the North American Continent, Florida is
a natural funnel for neotropical migratory birds (e.g., warblers, vireos, tanagers, orioles, and thrushes),
Comprehensive 34 Conservation Plan
which depend on scrub habitat areas for forage, cover, and rest prior to their long flight to Central and
South America. Occasionally, wood storks are observed flying over the Mainland and Jupiter Island
tracts. For many years, bald eagles have nested across U.S. Highway 1 in Jonathan Dickinson State
Park and are occasionally observed flying over the refuge.
Gopher tortoises occur on the refuge as well as the scrub lizard, corn snake, black racer, and green
anole. Seven wildlife scrub species are evaluated in greater detail as follows:
Florida scrub jay (Aphelocoma coerulescens)
Federal and State of Florida Threatened Species
The Florida scrub jay is endemic to the scrub habitat of Florida and is genetically and behaviorally
different from scrub jays of the western United States. Its range has been considerably reduced by
development, which has resulted in fragmented distribution of scrub habitat.
The jay has extremely specific habitat requirements within the scrub, including an open canopy and
open understory (Fernald 1989). Historically, habitat at the refuge supported a breeding population of
scrub jays, however, much of the scrub canopy has closed and there is dense undergrowth of
vegetation. Scrub habitat on adjacent Jonathan Dickinson State Park supports a larger, but declining
scrub jay population (Roberts, pers. comm. 2002).
Gopher tortoise (Gopherus polyphemus)
State of Florida Species of Special Concern
This species prefers xeric habitats with an abundance of herbaceous ground cover, an open canopy
and sparse shrub cover; this early successional scrub habitat is similar to the habitat requirements of
the Florida scrub jay (Franz 1986; Cox et al., 1987; Fernald 1989). The tortoise burrows 6 feet down,
for an average of 15 feet, into a well-drained sandy soil to prevent dessication and to regulate body
temperatures.
The gopher tortoise is designated as a keystone species in the scrub habitat of the refuge. Burrows
are known to provide habitat for up to 81 species of vertebrates and invertebrates. Thirty-two
commensal vertebrate species use the burrows, including the listed eastern indigo snake, Florida pine
snake, and gopher frog, which are described below. Tortoise dung provides the major food source for
many invertebrates, which, in turn, are food sources for the Florida mouse and gopher frog (Jackson
and Milstrey 1989; Cox et al., 1987; Fernald 1989).
The 1978 survey of gopher tortoise habitat on the refuge resulted in the discovery of two abandoned
burrows on the southernmost part of the refuge. In 1986, seven gopher tortoises were released, and
in 1992, four additional tortoises were released with the hope that they would form a local population.
Later that same year, a follow-up survey revealed six burrows at the site: four were active, one was
inactive, and one was abandoned.
In the winter of 1998-99, a portion of the sand pine scrub was surveyed for tortoises. Twenty-two
burrows were found: five were active, seven were inactive and ten were abandoned. Relatively few
tortoises are thought to be left on the refuge because the habitat has almost reached a climax
successional stage.
Hobe Sound National Wildlife Refuge 35
Eastern indigo snake (Drymarchon corais couperi)
Federal and State of Florida Threatened Species
The eastern indigo snake has decreased dramatically throughout the United States due to loss of
habitat. It has a home range between 125 to 250 acres, is diurnal, and feeds on small mammals,
birds, frogs, lizards, and other snakes (Richard Roberts, pers. comm. 2002). Gopher tortoise burrows
are particularly important to the indigo snake, since they can provide winter shelter and protection
from dessication (Fernald 1989). Since gopher tortoise burrow habitat is relatively scarce on the
refuge, sightings of indigo snakes may also be lower as a result. An underground survey of gopher
tortoise burrows is needed to determine the population level of the indigo snake and other species
that inhabit these burrows.
Florida pine snake (Pituophis melanoleucus mugitus)
State of Florida Species of Special Concern
This snake feeds on small mammals, birds, and lizards. It is closely associated with gopher tortoises
(Fernald 1989), as indicated by the fact that 85 percent of its life is spent in gopher tortoise burrows.
Surveys of gopher tortoise burrows are needed to assess the current status of this species on the
refuge.
Florida gopher frog (Rana capito)
State of Florida Species of Special Concern
This frog occurs in both active and inactive gopher tortoise burrows, but it prefers the former (Fernald
1989). It requires temporary grassy ponds for breeding, which could drive the frogs to move
elsewhere. Periodic surveys of known gopher tortoise burrows on the refuge are needed to determine
the presence of this species. In a survey conducted in 1999, no frogs were found (Gilligan 1999).
Florida mouse (Podomys floridanus)
State of Florida Species of Special Concern
This species is restricted to the State of Florida, and it has one of the narrowest habitat ranges of any
Florida mammal (Fernald 1989). It requires fire-maintained, dry, upland vegetative communities
located on deep, well-drained sandy soils. The current status of this species on the refuge is
unknown. During small mammal live-trapping surveys, conducted in 1999 and 2000, no Florida mice
were trapped.
Scrub lizard (Sceloporus woodi)
State of Florida Rare Species
According to Fernald (1989), this species is endemic to Florida, occurring in sand pine scrub and
associated xeric communities. It needs dry, well-drained sandy soils with numerous patches of open,
bare sand and high sun exposure. To maintain suitable habitat conditions, periodic major
disturbances of the canopy and ground cover are essential to preserve local populations. During the
1999 survey, this species was commonly found on the refuge (Gilligan 1999).
Plants. Plants are the best indicators of the sand pine scrub community. Over 75 species are found in this
habitat. The following 13 plants, native to sand pine scrub habitat, are evaluated in greater detail.
Comprehensive 36 Conservation Plan
Giant wild pine (also known as swollen wild pine) (Tillandsia utriculata)
State of Florida Endangered
As described in Long and Lakela (1971), this epiphyte=s leaves may reach nearly 7 feet in height.
Large plants often fall to the ground and continue to grow, flower, and fruit normally. The plant dies
after flowering. This species is known to occur in the sand pine scrub habitat of the refuge, although
its abundance is unknown. Its presence is threatened by the invasion of an exotic weevil that appears
to prefer wild pine for food, which, in turn, kills the plant.
Large-leaved rosemary (also known as large-flowered rosemary) (Conradina grandiflora)
State of Florida Endangered Species
This endemic shrub can reach over 3 feet in height, with few slender, usually curved branches (Long
and Lakela 1971). This endemic Florida species is usually found in sandy soil in scrub habitat and it
occurs on the refuge. The abundance of this species on the refuge is unknown.
Sand dune spurge (Chamaesyce cumulicola)
State of Florida Endangered Species
This endemic small herb has smooth, string-like, flexible stems and is found in south Florida (Long
and Lakela 1971). It shows a strong preference for disturbed, open areas, especially railroad rights-of-
way and roadsides adjacent to scrub (Bradley et al., 1998). This species occurs on the refuge,
though no population estimates have been made.
Nodding pinweed (also known as scrub pinweed) (Lechea cernua)
State of Florida Threatened Species
This small perennial herb can reach up to 2 feet in height, with leaves about 0.4-inch long, and 0.2-
inch wide. It primarily inhabits sunny open areas of scrub (Bradley et al., 1998) and occurs in sand
scrub vegetation (Long and Lakela 1971). This species is known to occur on the refuge, but its
abundance is unknown.
Reflexed (inflated) wild pine (also known as curly wild pine) (Tillandsia balbisiana)
State of Florida Threatened Species
These erect or pendent epiphytes grow on shrubs and trees in scrub habitat (Long and Lakela 1971).
It occurs on the refuge, but the population size is unknown. It is also at risk due to an exotic weevil,
which kills the plant.
Shell mound prickly pear cactus (also known as common prickly pear) (Opuntia stricta)
State of Florida Threatened Species
Long and Lakela (1971) describe this perennial species as reaching almost 7 feet in height, with few
to many green flowers. The cactus can be found in open and sunny areas of the refuge.
Unfortunately, it is thought to be endangered due to predation from the exotic moth (Cactoblastus
cactorum) (Bradley et al., 1998).
Hobe Sound National Wildlife Refuge 37
Lakela=s mint (Dicerandra immaculata)
Federal Endangered Species
This fragrant smelling mint was introduced to the refuge in 1991, to save it from extinction. Plants
were taken from the last remaining population near Vero Beach and Fort Pierce, Florida. They were
planted near the headquarters trail and in the Asand pit.@ Ongoing monitoring efforts, conducted by
the Fish and Wildlife Service=s Vero Beach Ecological Services Office, and the Bok Tower Gardens,
have shown plant growth and new seedling establishment in most areas.
Giant leather fern (Acrostichum danaeifolium)
State of Florida Threatened Species
This fern is confined to small wetlands located at the base of the scrub land hills. Small patches exist
in this limited environment.
Geiger tree (Cordia sebestena)
State of Florida Endangered Species
This tree, although occurring on the refuge, is north of its natural range. Its presence is most likely a
horticultural escapee.
Inkberry (Scaevola plumieri)
State of Florida Threatened Species
Habitat is being overtaken by its exotic relative, beach naupaka (Scaevola sericea). The invasive
beach naupaka plant grows quickly and completely covers the sand. The growth pattern prevents the
native inkberry from sprouting, spreading, or competing with the beach naupaka.
Four-petal pawpaw (Asimina tetramera)
Federal Endangered Species
This species has yet to be found on the refuge, but a population exists across U.S. Highway 1 in
Jonathan Dickinson State Park.
Burrowing four-o=clock=s (Okenia hypogaea)
State of Florida Endangered Species
This plant has not been recorded on the refuge; however, it is present at nearby Blowing Rocks
Preserve, which is owned by The Nature Conservancy.
Golden polypody (Phlebodium aureum)
State of Florida Threatened Species
This species roots in the boots of native cabbage palms. Its preferred growing location limits its ability
to spread. No effort has been made to determine the occurrence of this species on the refuge, but it
would most likely be in the hardwood hammocks.
Wetlands
In some areas of the Mainland Tract, the steep hillside plunges into small depressional wetlands
which contain giant leather fern, swamp and royal ferns, American beauty berry, and cabbage palm.
Comprehensive 38 Conservation Plan
The invasive species known as Old World climbing fern (Lygodium microphyllum) is an ongoing
problem in the wetland areas, requiring continual control. Lygodium can completely cover and
smother all plants including canopy trees.
Mangroves
Mangroves line the shoreline of the Indian River Lagoon. Generally, the red mangrove (Rhizhophora
mangle) colonizes the fringes of the waterway with its aerial prop roots providing shelter for numerous
marine animals. Mangrove prop roots decrease shoreline erosion by dampening the impact of high-energy
boat wakes. The resulting water clarity facilitates seagrass growth and establishment. Black
mangrove (Avicinnia germinans), with its vertical pnuematophores, is generally found immediately
inland of the red mangrove. The white mangrove (Laguncularia racemosa ) is found on slightly higher
elevations behind the black mangroves. Buttonwood (Conocarpus erecta) is also commonly found
associated with the mangrove community, occupying higher ground inland and out of direct contact with
brackish water.
A large percentage of mangroves have been disturbed by excessive wave action, removed prior to the
establishment of the refuge, or overtaken by invasive exotic plants. A mangrove re-planting program
is ongoing at the refuge in partnership with the Environmental Learning Center of Vero Beach. An
exotic plant removal program is also ongoing to maintain the shoreline clear of exotic plants, primarily
Australian pine and Brazilian pepper, which interfere with mangrove restoration.
Hammocks
Three hammock habitats comprised of hardwood tree species grow atop Native American Indian shell
middens. Species include such tropical trees as mastic, ironwood, marlberry, red and white stopper,
black stopper, paradise tree, poisonwood, white indigoberry, coral bean, lancewood, Jamaica caper,
and strangler fig. Hammocks are excellent refugia for neotropical migratory birds, land crabs, tree
frogs, and other animal species which need high humidity and/or dense cover. Although hammocks
occupy a very small percentage of the refuge=s acreage, they comprise about 20 percent of the plant
diversity on the refuge (Bergh 1998).
INDIAN RIVER LAGOON
The Indian River Lagoon is the most biologically diverse estuary in the United States. Because of its
diversity, it has been designated as an Estuary of National Importance. In an estuary, salt water from
the ocean mixes with fresh water from the inland; an estuary is of critical importance as a breeding,
staging, and resting area for fish, shellfish, reptiles, birds, and mammals.
The Indian River contains 1,800 species of wildlife and plants and it supports one of the most
productive aquatic faunas in the continental United States (Woodward-Clyde 1994). Species are
supported by natural communities, namely, freshwater inlets and seagrass beds, oyster and clam
beds, and diverse land forms and substrates. They are also supported by altered habitats such as
spoil islands and mosquito impoundments.
The growing population of south Florida, and its associated demand for limited water resources, is
affecting south Florida=s estuaries, including the Indian River Lagoon. Fresh water, destined for
estuaries, is being diverted for municipal and agricultural consumption, dams for irrigation, weirs for
flood control, storm water collection and treatment systems, and drainage canals. These diversions in
the natural cycle change the quantity and timing of water flows downstream to the estuary.
Hobe Sound National Wildlife Refuge 39
In addition to water diversions, removing vegetation from the land and replacing it with an impervious
surface can affect the natural flow of water to an estuary. Removal of the vegetation eliminates the
uptake of water, and adding impervious surfaces cuts percolation of water into underground aquifers.
The cumulative effect is that the estuary gets higher than normal freshwater input during the wet
season and lower than normal freshwater inputs during the dry season.
Fish
South Florida has a great diversity of fish species. Of the 1,800 species identified in the Indian River
Lagoon, at least 700 of them are fish species (Indian River Lagoon National Estuary Plan 1996;
Woodward-Clyde 1994). More than twice as many species of fish occur in the southern half of the
Indian River Lagoon, probably because of climate, presence of hard bottom and reef habitat, and the
presence of several inlets to the Atlantic Ocean (Woodward-Clyde 1994).
According to G. Gilmore et al., 1981, several major fish habitat types occur in the lagoon: freshwater
tributaries and canals; canal and river mouths; mosquito impoundments; mangrove marshes; open
sand bottoms; grass flats; lagoon reefs; and Atlantic inlets. These diverse aquatic habitats foster the
abundance of fishery resources that bring fishermen in great numbers to the refuge. The Florida
Committee on Rare and Endangered Plants and Animals (1992) has developed a category system,
similar to, but not the same as the federal designations, to which various fishes are assigned. These
categories are Threatened, Rare, and Species of Special Concern. The word AThreatened@ means
that the species are likely to become endangered in the state within the foreseeable future if current
trends continue. ARare@ includes species that are potentially at risk because they are found within a
restricted geographic range or habitat in the state or are sparsely distributed. ASpecies of Special
Concern@ warrant special attention because they are vulnerable to exploitation or environmental
changes and have experienced long-term population declines. The species assigned to the listed
categories below are those that have been observed on the refuge.
Threatened: Atlantic sturgeon (Acipenser oxyrinchus); opossum pipefish (Microphis brachyurus
lineatus); mangrove rivulus (Rivulus marmoratus); bigmouth sleeper (Gobiomorus dormitor); river goby
(Awaous tajasica); and slashcheek goby (Gobionellus pseudofasciatus).
Rare: Mountain mullet (Agonostomus monticola).
Species of Special Concern: Lake Eustis pupfish (Cyprinodon variegatus hubbsi); mangrove rivulus
(Rivulus marmoratus); striped croaker (Bairdiella sanctaeluciae); and spottail goby (Gobionellus
stigmaturus).
Many of these species follow the Gulf Stream and other currents into the south Florida area. The
opossum pipefish and many gobies depend on brackish water conditions for reproduction, such as
those found at the mouth of the St. Lucie River, although opossum pipefish have been found in Lake
Okeechobee (G. Gilmore, Harbor Branch Oceanographic Institute, pers. comm. 1996).
The favorite edible sport fish caught at the refuge include red drum (Sciaenops ocellatus); spotted sea trout
(Cynoscion nebulosus); snook (Centropomus sp.); snapper (Lutjanus sp.); shark (30-40 species); summer
flounder (Paralichthys dentatus); spot (Leiostomus zanthurus); bluefish (Pomotomus saltatrix); Atlantic
mackerel (Scomberomorus maculatus); weakfish (Cynoscion regalis); pompano (Trachinotus carolinus);
and Atlantic croaker (Micropogonias undulatus). The state threatened species of sport fish, common snook
(Centropomus undecimalis), is recovering from low population numbers in recent years.
Comprehensive 40 Conservation Plan
Seagrasses
Florida=s shallow coastal areas support six species of seagrass: manatee grass (Syringodium
filiforme); turtle grass (Thalassia testudinum); shoal grass (Halodule wrightii); star grass (Halophila
engelmanni); paddle grass (Halophila decipiens); and Johnson=s seagrass (Halophila johnsonii). The
most common grass in the Indian River Lagoon is manatee grass (Syringodium fliliforme). The grass
beds with the greatest density occur in shallow water where the salinity is fairly consistent. About 60
species of drift algae are growing on or found interspersed with marine grass beds. They begin as
attached forms but eventually break away, providing refugia for invertebrates, fish, and other algae.
Importance. Seagrass beds are considered some of the most productive habitat in the estuarine
system. They are important as nursery grounds for many fish species. Grass beds are used as cover
or foraging habitat by 29 fish species and the Atlantic bottlenose dolphin. They also serve as critical
food sources for the endangered West Indian manatee. In addition to being productive habitats,
seagrass beds improve water quality by removing nutrients, dissipating the effects of waves and
currents, entrapping silt, and stabilizing bottom habitats.
Issues. In September 1998, the National Marine Fisheries Service listed Johnson=s seagrass as
threatened under the Endangered Species Act of 1973. Its distribution is limited to the Indian River
Lagoon from Melbourne, south to Hobe Sound, and further southward to Lake Worth Lagoon and
Biscayne Bay. A decision on designation of critical habitat for Johnson=s seagrass is pending. See
Figure 10 for the distribution of Johnson=s seagrass at the refuge.
The seagrass communities of south Florida have experienced substantial declines in acreage and
quality in recent years. Since the 1940s, an estimated 30 percent of the seagrass communities have
been destroyed in estuarine habitats. This percentage of loss is also the case for the Indian River
Lagoon. More than 59,306 acres of seagrasses have been eliminated since 1987. The cause of this
loss includes such factors as: degraded water quality, freshwater flow management problems, severe
temperature variability, and dredging from boat propellers (Haddad and Sargent 1994). It has been
estimated that propellers alone have caused 64,200 acres of seagrasses to be moderately or severely
damaged (Haddad and Sargent 1994). Seagrass beds in Monroe and Dade counties, which are
located south of Martin, Collier, and Lee counties on the southwest Florida coast, have experienced
the heaviest damage from propellers.
Sea Turtles: Juvenile sea turtles use the Indian River Lagoon in their developmental stages
(Bresette, M.J., et al., 2002)
Mammals
Florida manatee (West Indian manatee). Manatees use the Indian River Lagoon, adjacent to the
refuge, predominately during the winter months to the delight of visitors. The relatively sheltered
waterway provides a resting and feeding area for the manatee as it travels south to the warm waters
of the Riviera Beach power plant. It forages primarily on seagrass beds and secondarily on over-hanging
mangroves and submerged, rooted, or floating species of plants. In 1976, nearly 10 percent
of the state=s manatee population was observed migrating through the lagoon along the refuge (Lund
1976; Packard 1981; Lefebvre and Powell 1990). Today, fewer sightings are recorded.
Ecological studies of seagrass beds and their use by manatees were performed at the refuge in 1976
and during 1988-1989. Seagrass beds appeared to be declining in area and productivity due to silt,
propeller dredging, and increased water turbidity from excessive power boat speeds.
Hobe Sound National Wildlife Refuge 41
Figure 10. Location of seagrass beds in relation to Hobe Sound National Wildlife Refuge
Comprehensive 42 Conservation Plan
Boating along the waterway is the largest threat to the manatee. Along the refuge, the state regulated
slow-speed zone for boats ends at Bridge Road, leaving 3 miles of unregulated speed along the
refuge boundary and another significant portion along the Peck Lake area. Propeller wounds and
blunt force trauma are two of the common causes of mortality. Blunt force trauma can occur from
power boats, as well as from personal watercraft.
In addition to boating impacts, red tides and cold stress are other common sources of manatee
mortality. While some manatees remain in both Hobe Sound and Jupiter Sound areas throughout the
year, others migrate up the coast. Deteriorating water quality, turbidity, and lack of food contribute to
the stress of migrating manatees.
Atlantic bottlenose dolphin. The only Indian River Lagoon resident cetacean is the Atlantic
bottlenose dolphin (Tursiops truncatus). Hundreds of dolphins, protected by the Marine Mammal
Protection Act of 1972, are known to occur throughout the lagoon. They feed on small fish, such as
mullet, spotted sea trout, silver perch, Atlantic croaker, and oyster toadfish. The average dolphin eats
about 9 kilograms (20 pounds) of fish per day (Woodward-Clyde 1994). Based on the estimated
population level in the lagoon, dolphins probably consume about 1,000,000 kilograms (2.2 million
pounds) of fish annually (Woodward-Clyde 1994).
Dolphins frequent seagrass beds in the summer, presumably due to the supply of pinfish, pigfish, and
mullet. In the winter, they are thought to move offshore; however, Beeler et al., (1988) believe that the
resident dolphin population in the lagoon does not go out into the Atlantic Ocean, but rather that
transient dolphins from ocean populations may come into the lagoon in the summer.
Studies conducted in1983 revealed that about 20 dolphin strandings a year occur in the lagoon
(Woodward-Clyde 1994). More recently, a fungal skin disease that causes lesions and secondary
bacterial infection is on the rise, infecting at least 12 percent of the population. Some scientists
suspect that the dolphin=s immune system is being suppressed by chemicals or biological agents
(i.e., toxic dinoflagellates) that occur in the Indian River Lagoon. Dolphin skin is sensitive to changes
in water salinity.
Reefs
Reefs are a prominent coastal resource in the South Florida Ecosystem, which contains several kinds
of coastal reef assemblages: worm reefs, vermetid reefs, and the more familiar coral reef. The refuge
supports the northernmost coral reef in the United States. The southern third of the Indian River
Lagoon contains a reef-like habitat, created by dredging along the edges of the Intracoastal
Waterway, which supports aquatic life such as gorgonian corals and other invertebrates. Also, in the
Atlantic Ocean, adjacent to the refuge, are expanses of hard bottom, which support invertebrate
growth, many juvenile fish species, and juvenile green sea turtles.
JUPITER ISLAND TRACT
The refuge=s 735-acre Jupiter Island Tract is composed primarily of Atlantic coastal dune, Australian
pine-lined lagoonal shore, mangrove swamps, mosquito impoundments, and 3.5 miles of sandy beach
(Figure 11).
Atlantic Coastal Dune
Three vegetative zones progress from ocean to inland: the foredune, the middledune and the
backdune. The foredune is nearest the ocean with characteristic plants such as sea oats, marsh
Hobe Sound National Wildlife Refuge 43
Figure 11. Vegetation on Jupiter Island tract, Hobe Sound National Wildlife Refuge
Comprehensive 44 Conservation Plan
elder, bay bean, railroad vine, and sea purslane. The middledune is inhabited and stabilized by sea
oats, bay cedar, beach sunflower, ink berry, beach star, black bead, and coastal panic grass. The
backdune is furthest from the ocean and supports the following native plants: saw palmetto, seashore
elder, sea grape, pigeon plum, Spanish bayonet, stinging nettle, and prickly pear.
While there are no records documenting the occurrence of beach jacquemontia (Jacquemontia
reclinata) on the refuge, according to the Multi-Species Recovery Plan (1999), this species once
occurred on Jupiter Island in Martin and Palm Beach counties. Currently, the northern most extent of
the species occurs 10 miles south of the refuge on Juno Beach (Palm Beach County). Beach
jacquemontia is a perennial vine which is found in open areas on the crest and lee sides of
stabledunes (Austin 1979). Loss of habitat and beach erosion led to listing this species as
endangered on November 24, 1993 (58 FR 62050). Considerable interest exists in the potential for
restoring beach jacquemontia to the refuge in partnership with Fairchild Tropical Gardens. Due to
positioning of the refuge within the Atlantic Flyway, the refuge dune and beach serve as important
resting and foraging areas for migrating shorebirds.
The southeastern beach mouse (Peromyscus polionotus niveiven