Research Product

A 13-week, refereed, inter-agency toxicity testing program involving five bioassay methods was used to document the effectiveness of shoreline bioremediation to accelerate toxicity reduction of an oiled sandy shoreline at Fowler Beach, Delaware, USA. The study was part of an international oiling experiment using a randomized complete block design with repeated measures. Bioremediation - treatment with nutrients or nutrients and oil-degrading bacteria - did not accelerate toxicity reduction. Nor did treatment increase toxicity at weeks 0. 6 or 12-13. However, results of one high-frequency test suggested there may have been a substantial delay in toxicity reduction due to treatment during the first few weeks of treatment. All tests provided information but the most sensitive tests were the 10-day sediment amphipod and grass shrimp embryo bioassays. Standardized sediment and water toxicity tests can play a valuable role in evaluating the effectiveness and effects of oil spill shoreline countermeasures.