United States
Environmental Protection
Agency
Office of Water
(4504F)
5JJ'1"-
13 A
EPA842-F-99-004P
April 1999
xvEPA
Characteristics
The Coastal Bays' estuary system includes
Assawoman, Isle of Wight, Sinepuxent, Newport and
Chincoteague Bays, plus 23 creeks and tributaries
which feed the bays. These bays are shallow water
lagoons, located behind Ocean City and Assateague
Island, where freshwater and saltwater mix. The
entire system covers 175 square miles, with an average
depth of approximately four feet. The Coastal Bays
are surrounded by a year-round population of 27,000
residents, however, during the summer vacation sea-
son, that number swells to more than 250,000 people
each week.
The Coastal Bays' watershed, the land area draining
into the bays, has a relatively small land-to-water
ratio—meaning the land area is a little less than twice
the size of the bays themselves. Unfortunately, this
means that anything placed, spilled, sprayed, drained
or buried in the watershed, has a good chance of even-
tually ending up in the bays. Compounding this prob-
lem is the bays' slow flushing rate. There are only two
openings from the ocean to the bays—through Ocean
City and Chincoteague inlets—this constricted access
means it takes 63 days for 99% of the water in
Chincoteague Bay to be replaced by tidal exchange.
Maryland Coastal Bays
National Estuary Program
DELAWARE
MARYLAND
N
Little Assawoman Bay
"Assawoman Bay
Isle of Wight Bay
Sinepuxent Bay
MARYLAND
ATLANTIC
Estuaries and other coastal and marine waters ate national
resources that are increasingly threatened by pollution, habitat
loss, coastal development, and resource conflicts. Congress
established the National Estuary Program (NEP) in 1987 to provide a
greater focus for coastal protection and to demonstrate practical, inno-
vative approaches for protecting estuaries and their living resources.
As part of the demonstration role, the NEP offers funding for mem-
ber estuaries to design and implement Action Plan Demonstration
Projects that demonstrate innovative approaches to address priority
problem areas, show improvements that can be achieved on a small
scale, and help determine the time and resources needed to apply
similar approaches basin-wide.
The NEP is managed by the U.S. Environmental Protection Agency
(EPA). It currently includes 28 estuaries: Albemarle-Pamlico
Sounds, NC; Barataria-Terrebonne Estuarine Complex, LA;
BamegatBay, NJ; Buzzards Bay, MA; Casco Bay, ME; Charlotte
Harbor, EL; Columbia River, OR and WA; Corpus Christi Bay, TX;
Delaware Estuary, DE, NJ, and PA; Delaware Inland Bays, DE;
Galveston Bay, TX; Indian River Lagoon, FL; Long Island Sound,
CTandNY; Maryland Coastal Bays, MD; Massachusetts Bays, MA;
Mobile Bay, AL; Morro Bay, CA; Narragansett Bay, RI; New
Hampshire Estuaries, NH; New York-New Jersey Harbor, NY and
NJ; Peconic Bay, NY; Puget Sound, WA; San Francisco Bay-Delta
Estuary, CA; San Juan Bay, PR; Santa Monica Bay, CA; Sarasota
Bay, FL; Tampa Bay, FL; and Tillamook Bay, OR.
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Ihe EEQbern
Currently, large bivalves are at historically low levels in the
coastal bays—oysters because of parasites, predators and foul-
ing organisms — hard clams due to overharvesting. These
species serve an important role in the bays as important filter
feeders and prey species. Filter feeding bivalves are impor-
tant in cycling organic matter from the water column to the
bottom, and serve as a key trophicJink between primary
producers and higher consumers. Over the past six decades
these ecological roles have considerably diminished in the
bays with the demise of the bays' larger bivalve species.
Historically, this region once supported large populations of
bay scallops. The ribbed mollusks, — a vital link in the coastal
bays food chain — were wiped out in the 1930s when eelgrass
was eliminated due to an eelgrass blight which devastated the
East Coast. The blue eyed bivalves need the grasses to escape
predators and siltation — when those grasses died, so did the
scallops. Although eelgrass has recovered, the bay scallop has
not returned, in large part due to the absence of any brood-
Stock population close enough to repopulate.the area.
In an effort to restore scallops to the Coastal Bays area, the
Scallop Restoration Project was implemented. The purpose
of the Scallop Restoration Project in Chincoteague Bay was
to provide and protect broodstock by planting hatchery-
reared juvenile scallops in predator exclosures. The scallops
arc expected to mature, reproduce and begin to restore diis
lost resource.
For more than a century, life on the Coastal Bays has
depended on the ocean, bays, and their tributaries. Fishing,
hunting, agriculture and more recently tourism, which sup-
port this coastal community are all dependent upon the land
and water resources of the bays area.
An environmental characterization of the bays has found
excessive levels of nitrogen resulting in algal blooms that
reduce oxygen levels in bay waters; loss of natural habitats for
fish, crabs, birds and other wildlife; declines in numbers of
fish, clams, crabs and other important species; local
bacterial contamination; and negative impacts from boating,
dredging, and other water-based activities.
Seagrass communities, which had been decimated, have
begun to recover in the southern and eastern sides of the bay,
particularly in Chincoteague Bay, but continue to be sparse
in the northern bays. In general, living resource communities
are more degraded in die northern bays and artificial canals,
while the southern bays are comparatively healthier.
The Maryland Coastal Bays Program, established in 1995, is
actively involved in the development of a management plan
to address these issues. In a collaborative partnership of citi-
zens and elected officials from Worcester County, Ocean
City, and Berlin, Maryland with representatives from various
federal and state governmental agencies, it is hoped that real-
istic and common sense solutions to these problems will be
developed.
Over 60 years ago, the bay scallop (Argopecten irradians) dis-
appeared from Chincoteague Bay soon after a disease virtual-
ly wiped out eelgrass (Zostera marina) beds in the region.
Although eelgrass has since repopulated a substantial portion
of Chincoteague Bay, bay scallop populations have not
recovered. In 1998 smaJl numbers were discovered in the
Maryland and Virginia portions of Chincoteague Bay, this
appears to be a range expansion of the North Carolina sub-
species.
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In 1996, Maryland's Department of Natural Resources'
Shellfish Monitoring Program initiated investigations into
restoring the bay scallop in Chincoteague Bay. Scallops
require vertical structure, such as seagrasses, for settlement, to
avoid predators and suffocation from silt. The scallops also
require salinities over 20 ppt, along with clean, hard packed
sand substrate throughout their
life cycle. Such conditions were
found to exist in a number of
areas along the eastern side of
Chincoteague Bay. That same
year, the Shellfish Monitoring
Program applied for and received
funding from NOAA's Fishing
Industry Grant Program (FIG)
to begin a bay scallop restoration
project.
In October, 1997, 533,000 seed
bay scallops were purchased
from a hatchery and transplanted to Chincoteague Bay. The
8 mm bivalves were placed into 80-foot square predator
exclusion pens, constructed in about 3 feet of water over sea-
grass beds. Records were kept on growth and survivorship,
along with measurements of recruitment success. By mid-
November, the scallops had tripled in size and survivorship
exceeded 85%. Overwintering mortality, usually substantial
throughout its geographical range, was relatively minor, on
the order of 25-30%.
In May, 1998, evidence of spawning was found in the trans-
planted scallops and the larvae were collected from the water
column. This initial spawning continued through early
August, a second reproductive event occurred in late
September. Spat collector bags were deployed to catch the
setting larval scallops and were retrieved in November. In
addition, the seagrass beds were surveyed for juvenile scal-
lops using a suction dredge sampler, which is non-destruc-
tive to eelgrass.
The original FIG grant provided for two years of scallop
seedlings. The second year was supplemented with a
Maryland Coastal Bays Program mini-grant, allowing the
planting of over 700,000 seed bay scallops with an average
length of 20 mm. The larger size should enhance survivor-
ship and reproductive effort next summer. Three additional
100-foot square exclosures, in proximity to the first pens,
have been constructed to protect the young scallops. Baited
crab pots were placed within the pens to further control and
monitor predators.
Success Sioriil"
The combined reproductive effort of the protected scallops,
along with the progeny of last year's planting, presumably
will overwhelm predation pressure sufficiently to allow a self-
sustaining population of bay
scallops to become established.
Monitoring by the Maryland
Department of Natural
Resources and the Virginia
Institute of Marine Science dis-
covered 'wild' bay scallops in
Chincoteage Bay this past sum-
mer. These observations mark
the return of this ecologically
and economically important
species to Chincoteague Bay
after a 60-year absence.
Scientists anticipate restoring
the scallops to their ecological niche will positively impact
everything from fish to water clarity.
Scallop restoration is just one part of the picture, the recent
comeback of seagrasses is integral to the return of these once
^imperiled mollusks. Although seagrass beds have been re-
establishing in Maryland's Coastal Bays, expansion to its his-
torical range may be limited by many factors, including
increased nutrient runoff from land, as well as physical
impacts from recreational boating and commercial fishing
activities, particularly hydraulic clam dredging.
Nutrients from stormwater runoff, atmospheric deposition,
and groundwater continue to threaten seagrass recovery in
some areas. Eutrophication may further impact the scallops
by increasing macroalgal populations, which can smother
existing seagrass. Projects are underway to develop habitat
criteria, i.e., water quality, sediment type, and wave exposure
for seagrasses within the bays.
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Impacts from recreational and commercial boating activities
are also being studied in an effort to protect the resource.
Hydraulic clam dredging has been identified as a potentially
significant factor impacting seagrass in the nordiern Isle of
Wight Bay. Restoring the scallop population will increase
scallop harvesting, therefore management measures to pro-
tect seagrasses during scallop harvesting need to be in place
to avoid ruining the resource.
Seagrasses must be protected from all of these-threats in
order to allow die scallops to survive. Because the grasses
serve as a nursery for almost every species of crab and fish
sought by recreational and commercial fisherman, scientists
hope management tools for the grasses will boost the local
economy and, along widi it, the local ecology.
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For,further!infpirma|!on,:..cont,,
Previous (Publications in th^ DeS1!!^®^!-^!^!!^ rejects Series
. . . ] , :•:.•.. •!. .'I ' .:" '.•: ••, • • .' .:••.! '• ' i .•••••!!.
Report Title
Biological Nutrients Removal Project
Buttermilk Bsy Colifomt Control Project:
Georgetown Stormwater Management Project
Texas Coastal Preserves Project
Shell Creek Stormwater Diversion Project
Cily Island Habitat Restoration Project
Buzzards Bay "Scp Track" Initiative
New Options for Dredging in Barataria-Teirebonne
Coquinn Bay Walk at Leffis Key
"Pilot Project Goes Airborne"
The National Estuary Program: A Ten-Year Perspective
Rock Barbs In Oregon's TUIamook Bay Watershed
The Weeks Bay Shoreline & Habitat Restoration Project
Evaluation of Shrimp Bycatch Reduction Devices in Texas Coastal Bend Waters
Evaluating Simple, Cost Effective Solutions for Reducing Stormwater and Urban Runoff Santa Monica, CA
National Estuary Program
Long Island Sound, CT/NY
Buzzards Bay, MA
Delaware Inland Bays, DE
Galveston Bays, TX
Puget Sound, WA
Sarasota Bay, FL
Buzzards Bay, MA
Barataria-Terrebonne Basin, LA
Sarasota Bay, FL
Narragansett Bay, RI
General NEP Discussion
Tillamook Bay, Oregon
Mobile Bay, AL
Corpus Christi, TX
J For^Copies ofjmy_of^thesejDublications contact:
National Clearinghouse for Environmental Publications Telephone: (513) 489-8190
Date Publication #
1995 EPA342-F-95-001A
1995 EPA342-F-95-001B
1995 EPA342-F-95-001C
1995 EPA842-F-95-001D
1995 EPAS42-F-95-001E
1995 EPA342-F-95-001F
1997 EPA842-F-97-002G
1997 EPA842-F-97-002H
1997 EPAS42-F-97-002I
1997 EPA342-F-97-002J
1998 EPA842-F-98-003K
1998 EPA842-F-98-003L
1998 EPA842-F-98-003M
1998 EPA342-F-98-003N
1999 EPAS42-F-99-0040
Facsimile: (513)489-8695
vxEPA
United States
Environmental Protection Agency
(4504F)
Washington, DC 20460
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