Toxicity Tests of the Sediments from the Port of Hampton Roads: Sublethal Effects

摘要

The present study represents an assessment of the potential sublethal effects of ocean disposal of sediments dredged from a highly industralized estuary. A series of sublethal bioassays were conducted to determine the effects of sediment fractions from various areas with the Port of Hampton Roads, Virginia on the physiological responses of the grass shrimp Palaemonetes pugio, and the sheepshead minnow Cyprinodont variegatus. Respiration and osmoregulation capacity were selected as two condition indices for assessing the overall health of the test organisms following exposure to the suspended solid fractions of sediments from the various dredge sites. All sediments meet EPA criteria for open ocean disposal except Southern Branch. These sediments produced significant sublethal effects in sediment elutriate bioassays. Subsurface samples taken in Southern Branch appear to be less contaminated than surface samples. No sublethal effects were observed for any of the elutriates of composite samples, which indicates that deepening operations should produce dredged material less contaminated that those routinely taken by maintenance dredging in the same areas.