Summary Study: Benthic Invertebrate Community
In the wake of the April 2000 Potomac Electric Power Company (PEPCO) pipeline
oil spill near Benedict, Maryland, the National Oceanic and Atmospheric
Administration (NOAA), the U.S. Fish and Wildlife Service (FWS), the Maryland
Department of Natural Resources (MDNR), and the Maryland Department of the
Environment (MDE) are conducting a natural resource damage assessment (NRDA),
which involves implementing studies to identify and quantify injured resources
and services. This fact sheet provides summary information about one of the
This project documents benthic invertebrate community abundance and assesses
the degree and extent of injury from the oil spill.
Three individual studies are being conducted in different habitats:
The subtidal habitat of Swanson Creek and the Patuxent River and its
The intertidal mudflats of the tributaries;
The intertidal marsh habitat of the tributaries.
Subtidal samples were collected using standard protocols similar to those used
in the Chesapeake Bay Benthic Monitoring Program. Intertidal samples were
collected using standard core sampling techniques. All samples were sieved
using 0.5-mm screen and sieve contents were preserved in 10-percent buffered
formalin. Laboratory processing will include animal identification and results
will be used to compare the benthic community abundance and diversity in areas
impacted by the spill with unaffected background areas. For example, the
subtidal sample results will be assessed using the Benthic Index of Biotic
Integrity (B-IBI) developed for monitoring the health of the benthic community
in the Chesapeake Bay.
The intertidal mudflat survey took place in September 2000, and intertidal
marsh sampling was conducted in July and September 2000. These samples are
being processed in the laboratory. Once processed, results will be evaluated to
assess potential injury.
The general sampling approach for assessing impact was developed by the NRDA
Council, which includes NOAA, FWS, MDNR, MDE, ST Services, and PEPCO. The
subtidal sampling plan was developed and implemented by Versar, Inc., as an
investigative component of its long-term monitoring program of the Chesapeake
Bay benthic invertebrate community. The Academy of Natural Sciences prepared
and implemented the intertidal mudflat sampling plan. Marsh biologists
representing NOAA, FWS, MDNR, MDE, ST Services, and PEPCO jointly developed and
implemented the intertidal marsh study.
For More Information
Contact one of the following individuals or visit a web site for more
NOAA Damage Assessment Remediation and Restoration Program
1305 East West Highway
Building 4, Room 10218
Silver Spring, MD 20910
This summary is meant to provide only an overview. More information on NRDA
studies can be found in the Swanson Creek administrative record located at the
Light Point Commerce Center
30383 Three Notch Road
Charlotte Hall, MD
Monday–Friday, 9 a.m. to 5 p.m.
Calvert Industrial Park
230 Bugeye Square
Prince Frederick, MD
Monday–Friday, 9 a.m. to 5 p.m.
Information Resource Center
Maryland Department of Natural Resources
580 Taylor Avenue, B–3
Annapolis, MD 21401
Monday–Friday, 8 a.m. to 4 p.m.