Summary

Description

Personnel from the U.S. Fish and Wildlife Service, Annapolis Field Office AFO, investigated the incidence of contaminants on Eastern Neck and Blackwater National Wildlife Refuges NWRs, Maryland and Bombay Hook and Prime Hook NWRs, Delaware. Agriculture was the principal land use within and adjacent to these NWRs, and in addition to industry, provided a potential source of contaminants. Inorganics, organophosphate pesticides, organochlorines, and PCB levels were measured in sediments and toxicity was assessed with Microtox bacterial assays. Concentrations of inorganics were generally low when compared to contaminant studies from the Chesapeake Bay basin; and levels approximated those expected for a relatively pristine area, such as a wildlife refuge. In addition, organic compounds were detected in only 2 samples, both at the detection limit. Microtox assays indicated toxicity in 1 sediment sample from Blackwater, Prime Hook, and Eastern Neck NWRs; however, there was no apparent relationship between these toxicities, contaminant concentrations, and water quality parameters. However, lead and chromium levels at several sampling sites were elevated. Lead accumulations most likely resulted from the deposition of spent lead shot, although the source of chromium contamination was not known. Overall, samples from Eastern Neck NWR contained significantly lower levels of inorganics compared to the other refuges.