The purpose of this study was to characterize selected bayside creeks of the Virginia portion of the Delmarva Peninsula with respect to chemistry and toxicity. The peninusla is an area in which the primary land use is agriculture. When compared to urbanized and industrialized areas, one might expect fewer persistent impacts but with potentially severe intermittent impacts. To detect persistent impacts, the ambient toxicity methods applied in the Chesapeake Bay area during the past decade were used. Severe intermittent impacts are generally undetected by these methods. Some agricultural practices and rain events can produce severe pulses of toxicity. To detect intermittent or pulsed impacts, in situ exposure with the grass shrimp, Palaemonetes pugio, were employed. Four creeks were selected for examination. Three creeks (Hungar, The Gulf, and Old Plantation), all in Northampton County, were known to have plasticulture of tomatoes and other nightshade vegetables. The fourth creek (Onancock), in Accomac County, was selected as free of plasticulture, but including an urbanized community (Onancock). The chemical characterization of water from was limited to measuring cadmium, cobalt, chromium, copper, mercury, nickel, lead, and zinc. At least two, and in two cases, five stations, were sampled in each creek. In no case were any metals present in concentrations exceeding water quality standards, acute or chronic. After observing water toxicity at all stations within tow creeks, stored samples were analyzed for chlorinated compounds and tributyltin. All measurements were below the detection limits.

"2001." "[EPA 903-R-01-002]." Description based on online resource; title from PDF title page (EPA, viewed March 15, 2021). Includes bibliographical references (pages 52-54).