ENVIRONMENTAL EVOLUTION OF THE CHINCOTEAGUE – ASSATEAGUE LAGOON/MARSH SYSTEM AS INFERED FROM THE SEDIMENT RECORD

Lagoons provide ideal conditions for stable marsh communities that are ecologically important in terms of species diversity. Found on the Eastern Shore spanning the border of Maryland and Virginia, the Chincoteague lagoon is protected along its length by Assateague Island, but is exposed to tidal influences through the Ocean City Inlet to the North and the Chincoteague Inlet to the South. The Chincoteague and Assateague lagoonal systems harbor many acres of ecologically important marshlands. Historically pristine, and still pristine in comparison to its Del Marva counterparts, the two bays are beginning to show signs of deteriorating health and environmental stress. This study focuses on the environmental impact of anthropogenic changes in sedimentation rates and trace metal and nutrient content creating a detailed history of contamination of the Chincoteague and Assateague bays over the past century.

Stratigraphic records preserved in the sediments will be used to reconstruct the history of the biogeochemical evolution of the lagoon/marsh ecosystem. Sediment cores taken from the lagoon will be dated and sediment fluxes and accumulation rates analyzed using Pb-210 and Cs-137 radioisotopes. The sediments will also be analyzed for trace metals and nutrients deposition over the past century. The environmental evolution and the associated anthropogenic stresses on the system as inferred from the relative changes in the dated cores will be compared to historical land use changes in the watershed. Probable contamination of the Eastern Shore lagoon and marshes associated with human development is bound to present a significant threat to the integrity of these most diverse and productive systems. The decline of the Chincoteague marsh life will endanger the success of migratory birds, the loggerhead turtle, and many commercially important fish species that are spawned and nursed there.