Recent wetland trends in southeastern Virginia: 1994 - 2000

              Recent Wetland Trends in Southeastern Virginia: 1994-2000
R.W. Tiner, J.Q. Swords, and H.C. Bergquist
U.S. Fish and Wildlife Service
National Wetlands Inventory Program
Northeast Region
300 Westgate Center Drive
Hadley, MA 01035
December 2005
This report should be cited as: Tiner, R.W., J.Q. Swords, and H.C. Bergquist. 2005.
Recent Wetland Trends in Southeastern Virginia: 1994-2000. U.S. Fish and Wildlife
Service, Northeast Region, Hadley, MA. NWI Wetland Trends Report. 17 pp.
TABLE OF CONTENTS
Page
Introduction 1
Study Area 1
Methods 4
Results 7
Year 2000 Wetland and Deepwater Habitat Status 7
Wetland Trends 9
Deepwater Habitat Trends 10
Summary 15
Acknowledgments 16
References 17
1
INTRODUCTION
The U.S. Fish and Wildlife Service (Service) has been actively mapping wetlands since
the mid-1970s through its National Wetlands Inventory Program (NWI). The NWI
Program has produced wetland maps for approximately 90 percent of the coterminous
United States (i.e., lower 48 states). In addition to the mapping, the NWI has conducted
wetland trends studies nationally and in specific geographic areas. Prior NWI studies
have documented wetland trends for Virginia for two time periods: 1) 1950s–1970s and
2) 1982-1989 (Tiner and Finn 1986, Tiner et al. 1994). Both studies identified
southeastern Virginia as a major area of wetland alteration with 80 percent of the state’s
loss of palustrine wetlands occurring here from the 1950s to the 1970s and nearly 5000
acres converted to upland between 1982 and 1989 (Tiner and Foulis 1994).
Consequently, this area may actually have experienced the heaviest recent wetland losses
in the Service’s Northeast Region (which includes 13 states from Maine through
Virginia) in the past 25 years since most Northeast states had some form of wetland
protection for freshwater wetlands prior to the 1990s. Southeastern Virginia and other
areas on the Coastal Plain are places with a high wetland to upland ratio that increases the
likelihood for wetland impacts with increasing population growth.
In the fall of 2001, the NWI received Service funding to update the wetlands inventory in
this area through the NWI’s national strategic mapping initiative. This mapping effort
produced information on current status of wetlands that could be used to assess recent
changes.
In 2004, the Region’s NWI Program received funding to conduct a wetland trends
analysis for a portion of southeastern Virginia. The purpose of this report is to present
the findings of that study.
Study Area
The study area is located in southeastern Virginia (Figure 1). It is represented by a 22-
quad area encompassing parts of four counties (Gloucester, Isle of Wight, James City,
and York) and eight independent cities (Chesapeake, Hampton, Newport News, Norfolk,
Poquoson, Portsmouth, Suffolk, and Virginia Beach) (Table 1). Three of the cities are
listed among the Nation’s 100 fastest growing cities (Virginia Beach #47, Chesapeake
#56, and Norfolk #77; http://www.citymayors.com). The total “land” area (upland plus
wetlands) amounts to 811 square miles, while waters account for an additional 470 square
miles. The study area includes 22-1:24,000 NWI maps: Benns Church, Bowers Hill,
Cape Henry, Deep Creek, Fentress, Hampton, Kempsville, Lake Drummond NW, Little
Creek, Mulberry Island, Newport News North, Newport News South, Norfolk North,
Norfolk South, North Bay, North Virginia Beach, Pleasant Ridge, Poquoson East,
Poquoson West, Princess Anne, Virginia Beach, and Yorktown.
2
Figure 1. Location of the 811-square mile study area in Virginia.
3
Table 1. Percentage of county or independent city located within the study area.
County or Independent City Percent within Study Area
Chesapeake 70
Gloucester 2
Hampton 67
Isle of Wight 22
James City 5
Newport News 97
Norfolk 93
Poquoson 59
Portsmouth 100
Suffolk 15
Virginia Beach 76
York 49
4
METHODS
Wetland trends analysis involves examination of two dates of aerial photographs
covering the same area. Such examination identifies areas of change due to numerous
factors. Changes can be attributed to two basic causes: natural processes and human
activities. Natural processes include succession from one plant community to another,
beaver activity, fire, and sea level rise. Some changes in plant communities are brought
about by human actions such as timber harvest, partial drainage, and pollution (e.g., water
quality degradation). Other human-induced changes largely result in losses of wetlands
due to filling, dredging/excavation, impoundment, stream channelization, and drainage.
The existing NWI data that was derived from 1980s 1:58,000 color infrared photography
served as the foundation for this update. From 2000-2001, the NWI Program updated
wetland geospatial data for southeastern Virginia using two sources of aerial
photography: 1994-1:40,000 color infrared photographs and 2000-1:40,000 black and
white (panchromatic) photographs. The photography was acquired by the U.S.
Geological Survey’s National Aerial Photography Program. With this imagery, the
minimum mapping unit for wetland inventory purposes is about 1 acre, recognizing the
inherent limitations of photointerpretation for mapping wetlands (Tiner 1990). Such
targets are for general guidance as in practice, many conspicuous, smaller wetlands are
often mapped. For example, a recent Virginia Institute of Marine Sciences study found
that more than one third of the 1,200 vegetated wetlands examined in the coastal plain
were less than one acre in size (David L. Davis, pers. comm. 2005). Small ponds may be
the most common wetland type frequently mapped below the target mapping unit.
Wetlands were added, deleted, or their boundaries were reconfigured to represent more
contemporary conditions. Wetlands were classified according to the Service’s official
wetland classification system (Cowardin et al. 1979) which has been adopted by the
Federal Geographic Data Committee as the national wetland classification standard for
reporting wetland trends statistics. Table 2 lists some of the more common wetland types
in the study area.
The NWI database was first updated using the 1994 imagery creating a 1994 wetland
geospatial database using ArcGIS 8.3 (Environmental Systems Research Institute, Inc.,
ESRI). Next, the 2000 photography was used to bring the data closer to current-day
conditions. A copy of the original 1994 data was retained while these data were brought
up-to-date by interpreting the 2000 imagery.
To conduct the trends analysis, changes between the 1994 mapped wetlands and the 2000
dataset were highlighted by the union geo-processing function of ArcGIS 8.3. A trends
data layer was created through this process. Photointerpreters then re-examined the aerial
photos using a digital transfer scope (DTS) to document the cause of the changes. Land
use and land cover classifications follow Anderson et al. (1976) (Table 3). The minimum
area of change detected was approximately 0.5 acre. It must be recognized that some
wetlands, especially evergreen forested types and drier-end wetlands (e.g., seasonally
saturated) are difficult to identify through photointerpretation (Tiner 1990) and that the
5
changes recorded involve wetlands that were mapped by the NWI Program. The findings
therefore are probably a conservative estimate of actual changes.
------------------------------------------------------------------------------------------------------------
Table 2. Generalized classification of common wetland types in the study area following
Cowardin et al. (1979).
Common Name Cowardin et al. Type NWI Code
Salt marsh Estuarine Intertidal Emergent Wetland E2EM__
Salt shrub swamp Estuarine Intertidal Scrub-Shrub Wetland E2SS___
Saltwater tidal flat Estuarine Intertidal Unconsolidated Shore E2US___
Freshwater tidal flat Riverine Tidal Unconsolidated Shore R1US___
Freshwater marsh Palustrine Emergent Wetland PEM___
Wet meadow Palustrine Emergent Wetland PEM___
Deciduous shrub swamp Palustrine Scrub-Shrub Wetland, Broad-
Leaved Deciduous PSS1___
Evergreen shrub swamp Palustrine Scrub-Shrub Wetland, Needle-
Leaved Evergreen PSS4___
Deciduous wooded swamp Palustrine Forested Wetland, Broad-
Leaved Deciduous PFO1___
Evergreen wooded swamp Palustrine Forested Wetland, Needle-
Leaved Evergreen PFO4___
Farmed wetland Palustrine farmed Pf
Pond Palustrine Unconsolidated Bottom PUB___
Pond (dry) Palustrine Unconsolidated Shore PUS___
6
Table 3. Land use/cover classifications used for this project (adapted from Anderson et
al. 1976). Note: Transitional land is land undergoing alteration with intended use
unknown.
Land Use/Cover Type Code
Residential Development 110
Commercial Development 120
Industrial Development 130
Transportation/Utilities 140
Airport 144
Golf Course 191
Agriculture (Crops/Pasture) 210
Mixed Fields/Shrub Thickets 330
Deciduous Forest 410
Evergreen Forest 420
Mixed Forest 430
Gravel Pit 753
Transitional Land 760
7
RESULTS
Year 2000 Wetland and Deepwater Habitat Status
In 2000, wetlands occupied nearly 157,000 acres, representing 30 percent of the land area
within the southeastern Virginia study area. Palustrine wetlands made up 77 percent of
the wetlands (120,981 acres) with estuarine wetlands comprising the bulk of the
remaining acreage (32,975 acres). Fourteen percent of the palustrine wetlands are
freshwater tidal wetlands. Overall, forested wetlands predominated, representing 65
percent of the area’s wetlands (102,485 acres including 378 acres of estuarine forests).
Estuarine emergent wetlands were second-ranked in extent, accounting for 17 percent
(26,143 acres), followed by palustrine scrub-shrub wetlands (7,811 acres; 5%), palustrine
emergent wetlands (6,525 acres; 4%), estuarine unconsolidated shore (5,730 acres; 4%),
and ponds (palustrine unconsolidated bottoms and shores, 4,424 acres; 3%).
Estuarine wetlands totaled nearly 33,000 acres, with slightly brackish (oligohaline)
wetlands accounting for 17 percent of the acreage. Seventy-nine percent of the estuarine
wetland acreage was emergent wetland with the majority being irregularly flooded. Only
720 acres of regularly flooded emergent wetlands were inventoried, while 2,630 acres
(10.1%) were assigned “unknown” water regime. The “unknown” regime indicates
transitional intertidal marsh between regularly flooded or irregularly flooded marsh and
likely represents high marsh evolving into low marsh due to sea-level rise. Nearly 90
percent of the estuarine unconsolidated shore (tidal flat) was either regularly flooded or
irregularly exposed, with the remainder being irregularly flooded.
The study area had nearly 227,000 acres of deepwater habitats excluding marine waters
(Atlantic Ocean) on the NWI maps. Estuarine waters dominated this coastal region with
220,872 acres inventoried. Fresh waterbodies included 4,275 acres of lacustrine waters
(reservoirs and large impoundments) and 1,429 acres of riverine waters. Over 4,400
acres of freshwater ponds were also inventoried but they are included in the wetland
totals since they are considered a type of wetland according to the Cowardin et al.
classification system.
8
Table 4. Acreage summary for wetlands in the study area for 2000. Note: Types include
mixed classes where designated class predominated.
NWI Wetland Type Acreage
Estuarine Wetlands
Emergent 26,142.8 (5,519.5 = oligohaline)
Forested 377.5 (129.1 = oligohaline)
Rocky Shore 3.4
Scrub-Shrub 720.5 (76.6 = oligohaline)
Unconsolidated Shore 5730.4 (8.7 = oligohaline)
------------------------------- ----------------------------------------
Subtotal Estuarine 32,974.6 (5,733.9 = oligohaline)
Lacustrine Wetlands
Vegetated 37.7
Nonvegetated 2180.9
------------------------------- ----------
Subtotal Lacustrine 2218.6
Marine Wetlands 371.4
Palustrine Wetlands
Aquatic Bed 25.9
Emergent, non-Phragmites 6486.3 (646.9 = tidal)
Emergent, Phragmites 38.4 (3.8 = tidal)
Farmed 87.9
Forested, Broad-leaved
Deciduous 83,958.4 (10,063.0 = tidal)
Forested, Bald Cypress 1590.9 (71.0 = tidal)
Forested, Broad-leaved Evergreen 2.3
Forested, Needle-leaved Evergreen 16,440.0 (4,081.6 = tidal)
Forested, Dead 116.0
Scrub-Shrub, Deciduous 4539.4 (536.6 = tidal)
Scrub-Shrub, Broad-leaved
Evergreen 2059.4 (1,567.9 = tidal)
Scrub-Shrub, Needle-leaved
Evergreen 1212.4 (403.5 = tidal)
Unconsolidated Bottom 4273.9
Unconsolidated Shore 150.1 (0.2 = tidal)
---------------------------------- ------------------------------------
Subtotal Palustrine 120,981.3 (17,374.5 = tidal)
GRAND TOTAL 156,545.9
9
Wetland Trends
From 1994 to 2000, the study area experienced a net loss of nearly 2,100 acres of
wetlands (Table 5). This amounts to a 1.3 percent decline in just six years. Vegetated
wetlands declined by 2,545 acres while nonvegetated wetlands (mainly ponds) increased
by about 450 acres. The types that changed the most were forested wetlands with a net
loss of 3,306 acres, palustrine emergent wetlands with a net gain of 930 acres, and ponds
(palustrine unconsolidated bottoms and shores) with a net gain of nearly 500 acres.
Estuarine wetlands declined by 101 acres.
Causes of Wetland Changes
Changes for each major wetland type are outlined in Table 6. Over 2,400 wetland acres
were converted to upland and about 85 acres to estuarine deepwater habitat. Nearly
1,100 acres of new palustrine emergent wetlands became established between 1994 and
2000, largely at the expense of forested wetlands. This gain and the associated “loss” of
forested wetlands were due to timber harvest practices which also undoubtedly accounted
for the 10-acre gain in palustrine scrub-shrub wetland (Table 6). When forested wetlands
are cutover, a cycle of changing plant communities begins. The initial vegetative re-growth
is typically herbaceous species and seedlings of woody plants. This phase is
often succeeded by a mixed community of shrubs and emergents, then later a “shrub”
community of true shrubs and tree saplings, and finally after more than 25 years, trees
(i.e., woody plants >20 feet tall) predominate, re-establishing the forested wetland.
Consequently, much of the “loss” of forested wetland as well as the “gain” in emergent
wetlands as detected by this and other wetland trend studies in forested regions often
reflects a temporary vegetation change following timber harvest, although the change
may last for more than 20 years. Such changes are treated as changes in type and not as
conversions to upland; they have no effect on the overall net change in wetland acreage.
Actual losses of wetland to upland and deepwater habitat totaled 2,508 acres, while
changes from one wetland type to another accounted for 1,220 acres of changes (Table
6). Only one acre of deepwater habitat was converted to upland, whereas 2,422 acres of
wetlands were developed. Most of the wetland losses to upland involved residential
development (1,580 acres or 65.2% of overall loss; Table 7) and affected forested
wetlands (2,124 acres or 87.7% of the loss). Loss to “transitional land” (lands under
active development for unknown purpose) was responsible for 19 percent of the
converted wetlands (468 acres). With all the residential development going on in this
area it is likely that much of this lost acreage may be home sites today. Commercial
development was the third-ranked cause of wetland conversion to upland (6.8%, 165
acres). Industrial development was next-ranked, accounting for nearly four percent of the
conversions to upland (92 acres). Transportation/utilities and golf course construction in
wetlands were each responsible for two percent of the losses to upland (49 and 48 acres,
respectively). Airport construction (20 acres, 0.8%) and sand and gravel pit operations (1
acre, 0.1%) make up the remainder of the wetland losses to upland.
10
Conversion of forested wetlands to upland amounted to more than 2,100 acres, with 71
percent of this loss attributed to residential development. Transitional land was the
second-leading cause of forested wetland loss to upland, accounting for 16 percent (or
343 acres) of this loss. Commercial development was the next-ranked cause of these
forested losses, comprising nearly six percent of the total loss (119 acres). Timber
harvest of forested wetlands affected over 1,000 acres (Table 6).
Eighty-three percent of the losses of estuarine wetlands were largely attributed to
conversion to open water (85 acres) (Table 6). This change was likely due to
submergence of wetlands by rising sea level since the excavated modifier (“x”) indicative
of dredging was not applied to the deepwater habitat. Only 15 acres of estuarine
wetlands (emergent) were converted to upland with nearly all of this being in a
transitional state (i.e., land use was not detectable) (Table 7).
Deepwater Habitat Trends
All deepwater habitats experienced net increases in acreage between 1994 and 2000.
Lacustrine water acreage rose by 146 acres, estuarine waters by 79 acres, and riverine
waters by 8 acres. The gain in lacustrine and riverine waters came from upland, whereas
the gains in estuarine waters came from tidal flats (estuarine unconsolidated shores, 46
acres) and salt marshes (estuarine emergent wetlands, 34 acres and estuarine scrub-shrub
wetlands, 4 acres) (Table 6). These changes are likely due to submergence of wetlands
by rising sea level since the excavated modifier (“x”) indicative of dredging was not
applied to the deepwater habitat. A small amount of estuarine waters was converted to
upland (1 acre) and ponds (4 acres).
11
Table 5. Comparison of wetland acreages 1994-2000 for the study area. Note: Types
include mixed classes where designated class predominated.
NWI Wetland Type 1994 2000 Net Acreage Change
Acreage Acreage (% Change)
Estuarine Wetlands
Emergent 26,193.8 26,142.8 -51.0 (0.2)
Forested 377.5 377.5 0 (0)
Rocky Shore 3.4 3.4 0 (0)
Scrub-Shrub 724.6 720.5 -4.1 (0.6)
Unconsolidated Shore 5776.7 5730.4 -46.3 (0.8)
------------------------------- ------------ ----------- --------------
Subtotal Estuarine 33,076.0 32,974.6 -101.4 (0.3)
Lacustrine Wetlands
Vegetated 37.7 37.7 0 (0)
Nonvegetated 2,180.9 2,180.9 0 (0)
------------------------------- ---------- ---------- --------------
Subtotal Lacustrine 2,218.6 2,218.6 0 (0)
Marine Wetlands 371.4 371.4 0 (0)
Palustrine Wetlands
Aquatic Bed 25.9 25.9 0 (0)
Emergent 5,594.4 6,524.7 +930.3 (16.6)
Farmed 89.7 87.9 -1.8 (2.0)
Forested 105,413.5 102,107.6 -3,305.9 (3.1)
Scrub-Shrub 7,927.3 7,811.2 -116.1 (1.5)
Subtotal P-vegetated 119,050.8 116,557.3 -2,493.5 (2.1)
Unconsolidated Bottom 3,811.2 4,273.9 +462.7 (12.1)
Unconsolidated Shore 113.8 150.1 +36.3 (31.9)
Subtotal P-nonvegetated 3,925.0 4,424.0 +499.0 (12.7)
---------------------------------- ------------ ------------ ------------------
Subtotal Palustrine 122,975.8 120,981.3 -1,994.5 (1.6)
GRAND TOTAL 158,641.8 156,545.9 -2,095.9 (1.3)
12
Table 6. Changes in wetland types in southeastern Virginia (1994-2000).
2000 Type
Upland Deepwater Nonvegetated Wetland Vegetated Wetland Total
Habitat Change
1994 Type1 E1UB PUS PUB E2EM PEM PSS PFO
E2EM 15.0 34.1 -- 0.2 -- 1.7 -- -- -51.0
E2SS -- 4.1 -- -- -- -- -- -- -4.1
E2US -- 46.3 -- -- -- -- -- -- -46.3
PEM (tidal) 25.4 -- -- 0.8 -- -- -- -- -26.2
PEM (nontidal) 126.0 -- -- -- -- -- 10.1* -- -136.1
PSS (tidal) 3.8 -- -- 3.2 -- 0.4 -- -- -7.4
PSS (nontidal) 100.4 -- -- -- -- 15.7 -- 2.7 -118.8
PFO (tidal) 56.1 -- -- 3.6 20.5 -- -- -- -80.2
PFO1 (nontidal) 1,634.5 -- 7.7 57.5 9.3 773.6* -- -- -2,482.6
PFO4 (nontidal) 433.0 -- 6.2 8.6 -- 298.0* -- -- -745.8
PUB 19.1 -- -- -- -- -- -- -- -19.1
PUS 8.2 -- -- -- -- -- -- -- -8.2
Pf 1.8 -- -- -- -- -- -- -- -1.8
-------------------- ----------- ----- ----- ----- ----- ----- ----- ----- ---------
Total Change 2,423.3 84.5 13.9 73.9 29.8 1,089.4 10.1 2.7 3,727.6
*Likely vegetation change following timber harvest.
1 See Table 2 for wetland type names for these codes.
13
Table 7. Causes of wetland and deepwater habitat conversion to upland (1994-2000).
1994 Type 2000 Upland
Land Use Acres
E1UB Industrial Development 1.25
TOTAL Deepwater Habitat Loss 1.25
E2EM Residential Development 0.92
Transitional Land 14.10
Subtotal 15.02
TOTAL Estuarine Wetland Loss 15.02
PEM (tidal) Residential Development 0.36
Transitional Land 25.00
Subtotal 25.36
PEM (nontidal, A, B, C,
E, F) Residential Development 20.61
Commercial Development 37.13
Industrial Development 5.15
Transportation/Utilities 9.72
Airport 17.63
Sand/Gravel Pit 0.44
Transitional Land 35.31
Subtotal 125.99
Total PEM Loss 151.35
Pf (farmed) Transitional Land 1.76
PFO1 (nontidal, A, B, C,
E, F including ¼ mixes) Residential Development 1,184.23
Commercial Development 97.69
Industrial Development 55.44
Transportation/Utilities 34.33
Airport 1.84
Golf Course 46.65
Transitional Land 214.35
Subtotal 1,634.53
14
PFO (tidal) Residential Development 42.82
Commercial Development 1.20
Transitional Land 12.07
Subtotal 56.09
PFO4 (nontidal, A, B, C,
E, F, including 4/1 mixes) Residential Development 288.28
Commercial Development 19.89
Industrial Development 5.98
Transportation/Utilities 2.61
Transitional Land 116.33
Subtotal 433.09
Total PFO Loss 2,123.71
PSS (nontidal, A, B, C,
E, F, including mixes) Residential Development 31.86
Commercial Development 6.64
Industrial Development 9.76
Transportation/Utilities 2.51
Golf Course 1.51
Transitional Land 48.13
Subtotal 100.41
PSS (tidal) Residential Development 3.29
Transitional Land 0.52
Subtotal 3.81
Total PSS Loss 104.22
PUB Residential Development 7.37
Commercial Development 2.24
Industrial Development 7.85
Airport 0.68
Sand/Gravel Pit 0.97
Subtotal 19.11
PUS Industrial Development 8.20
Total PUB/US Loss 27.31
TOTAL Palustrine Loss 2,408.35
TOTAL WETLAND LOSS 2,423.37
15
SUMMARY
Thirty percent of this 811-square mile area in southeastern Virginia is comprised of
wetlands. Nearly 157,000 acres of palustrine and estuarine wetlands were inventoried
based on 2000 aerial photography. Palustrine forested types accounted for 65 percent of
the wetland acreage, while estuarine emergent wetlands made up 17 percent of the
wetlands.
From 1994 to 2000, this region experienced a net loss of nearly 2,100 wetland acres.
This amounts to a 1.3 percent decline in just six years. More than 3,300 acres of forested
wetlands were lost, with over 2,000 acres converted to upland (mostly residential
development) and over 1,000 acres transformed to palustrine emergent wetlands by
timber harvest. The latter changes are temporary, but will last until forest cover is
reestablished. Losses of palustrine forested wetlands amounted to three percent of the
1994 forested wetland acreage. In general, vegetated wetlands were converted to upland
with relatively little change in type other than following timber harvest. On the other
hand, substantial gains in nonvegetated wetlands (i.e., ponds) were detected with a net
gain of nearly 500 acres. This gain represents an almost 13 percent increase from 1994.
Estuarine wetlands were less threatened by development than palustrine wetlands.
However, significant acreage of these wetlands (i.e., 85 acres) became estuarine
deepwater habitats, presumably due to rising sea level.
It is interesting to note that three major wetland regulatory events took place during the
study time period: 1) in 1998, the original “Tulloch Rule” was invalidated, thereby
allowing land clearing of wetlands with earth-moving equipment without federal permit
(in 2001, such activities again became subject to federal permits through the new
“Tulloch Rule”), 2) in 1999, the Corps nationwide permit number 26 expired (it had
allowed wetland filling up to 10 acres simply upon notifying the Corps; no individual
permit was required), and 3) in 2000, Virginia’s General Assembly enabled the Virginia
Department of Environmental Quality to regulate nontidal wetlands (Kim Marbain, pers.
comm. 2005). We expect that wetland losses will significantly decline with improved
wetland protection resulting from the combined effects of the new Tulloch rule, statewide
wetland regulation through the Virginia Water Protection Permit Program, and the
elimination of nationwide permit number 26.
16
ACKNOWLEDGMENTS
This work was supported by the Service’s National Wetlands Inventory Program through
funding from the Washington Office. The analysis of wetland trends was performed by
John Swords, Assistant Regional Wetland Coordinator, Northeast Region, with Herb
Bergquist providing GIS support and data tabulation. Although not part of this project,
wetland photointerpretation for the 2000 era was done by Gabriel DeAlessio. Ralph
Tiner, Regional Wetland Coordinator, initiated the study, analyzed the results, and
prepared the report.
The following individuals reviewed the draft manuscript and we thank them for their
comments: Karen Mayne and Kim Marbain (FWS, Virginia Field Office), Jennifer
Greiner (FWS Chesapeake Bay Program Liaison), Catherine Harold and David Davis
(Virginia Department of Environmental Quality, Office of Wetlands and Water
Protection), and Kirk Havens (Associate Director, Center for Coastal Resources
Management, Virginia Institute of Marine Sciences).
17
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