Coastal Watershed Condition Assessments
PI: Merryl Alber (Dept of Marine Sciences, Univ of Georgia, Athens,
Support: National Park Service (U.S. Department of the Interior)
Timeframe: 2003 - 2005
The National Park Service is in the process of conducting a series of watershed assessments, "To determine the
status of coastal park resources including water quality, habitat condition,
invasive species, extractive uses, coastal development, and other issues
affecting their condition, to identify knowledge gaps, and to make recommendations
for further studies that address resource threats." (http://www.nature.nps.gov/water/watershed_reports/WSCondRpts.cfm)
The two Georgia parks evaluated (Cumberland Island National
Seashore and Fort Pulaski National Monument) are
part of a larger southeastern pilot program including parks in North and
South Carolina, Florida, and Texas. Studies in Alaska and the Pacific
west have also been initiated. For more information about other parks
in the program, refer to the National Park Service website, http://www.nature.nps.gov/water/watershedconds.cfm
Cumberland Island National Seashore Assessment
Merryl Alber, Janice Flory, Karen Payne
Overview and findings:
Cumberland Island is a barrier island located in the Atlantic Ocean
off the coast of Georgia just north of the Florida border. The east coast
of the island is an almost continuous strip of beaches that face the ocean,
whereas the remaining shore is a network of tidal creeks that flow through
salt marshes and eventually open out into coastal water. Habitats associated
with the island include marine areas (offshore water and associated bottom
areas, tidal creeks, saltwater ponds) and associated structures (i.e.
jetties, docks); intertidal areas (beaches, salt marshes, tide pools);
upland areas (dunes, maritime forest, remnant agricultural areas); and
inland ponds (both brackish and fresh water). Although Cumberland Island
is considered relatively pristine in comparison to more highly developed
barrier islands, both point and nonpoint sources of pollutants can be
found nearby that have the potential to affect the island.
The largest potential water quality problem identified was low dissolved
oxygen in Cumberland Sound, but there are also potential problems associated
with nutrients and contaminants. Fecal bacteria are a potential problem
in areas accessed by feral horses. In terms of population effects, potential
problems exist as the result of the introduction of exotic species in
the area. In addition, fish and shellfish (particularly crab) landings
have decreased considerably in recent years. Habitat disruption on the
island occurs from the activities of feral horses, particularly in tidal
creeks and inland ponds. Erosion from boat traffic is also a potential
problem in this regard. There was a lack of available information regarding
water quality in the tidal creeks.
There are a number of additional and/or continuing observations that
would be useful to have to better evaluate coastal water resources in
the region. This includes improved access to existing data; continued
monitoring of water conditions (particularly in light of impending development
in the area); and selection and monitoring of sentinel organisms in different
habitat types that could act as indicators of degrading water quality.
In addition, it is important to clarify the hydrology in the area so that
the watershed can be better-defined and the links between upstream pollutant
and delivery to the area are betterestablished. In this regard, it would
also be useful to determine the residence time of the different sub-water
bodies (i.e. tidal creeks; Cumberland Sound) so that there is a means
to quantify exposure and the potential vulnerability of different areas
to water-borne pollutants.
Fort Pulaski National Monument Assessment
Overview and findings:
Fort Pulaski National Monument is located near the mouth of the Savannah
River Estuary in Georgia. The Park is composed of a series of small islands
surrounded by salty, tidally influenced river channels and creeks. The
primary habitats in the Park are maritime forest, intertidal salt marsh,
and the main channel of the estuary with its associated tidal creeks.
This report provides information on the water quality and biological resources
of the Park as well as the potential sources of pollution to the region.
The study area for this report focused primarily on those parts of the
three counties closest to Ft. Pulaski (Chatham, and Effingham County (GA)
and Jasper County, (SC)) that fell within the lower Savannah River basin
(USGS Hydrologic Unit Code 03060109), as well as the portion of Chatham
County that surrounds McQueens Island, which falls primarily in HUC 03060204.
Although there are no real sources of pollutants at Fort Pulaski itself,
both point and nonpoint sources of pollutants can be found nearby that
have the potential to affect its water resources.
Wastewater treatment plants and pulp and paper mills are the primary
point sources of organic matter and nutrient loading in the lower Savannah
River watershed. Numerous industries (including 20 Superfund sites) release
contaminants to the groundwater, soil, or air, and there are also contaminants
associated with dredge spoil sites. Non-point loading of pollutants occurs
via stormwater runoff and atmospheric deposition. In addition, two major
nuclear facilities and the Port of Savannah are located upstream of the
Fort Pulaski study area.
There have been numerous alterations to the Savannah River that have
likely affected conditions at Fort Pulaski, including deepening and widening
of the channel for navigation and the operation of tide gates and upstream
dams. At present, a proposal by the Georgia Ports Authority to further
deepen the channel is being considered. The Savannah Harbor Expansion
Project would involve deepening 35 miles of the navigation channel an
additional 6 to 8 feet and widening bends at 12 locations. Concerns associated
with the proposed deepening include its effects on water conditions (i.e.
salinity, dissolved oxygen, water clarity, contaminant concentrations),
and how those in turn might affect freshwater wetlands and aquatic resources
(i.e. striped bass, shortnose sturgeon). Ongoing population growth and
accompanying development in the area is also a concern, as it will likely
alter the amount and quality of overland runoff.