Acute laboratory toxicity tests were performed on surficial sediments collected from 1176 locations throughout 22 estuarine areas in the United States. Toxicity was determined with three standardized procedures:  10-day amphipod survival tests with solid-phase (bulk) sediments; 5-min microbial bioluminescence tests with organic solvent extracts of the sediments; and either 1-h sea urchin fertilization tests or 48-h mollusc embryo tests with the porewater of the sediments. Test results were weighted to the sizes (km2) of the geographic strata in which samples were collected. Selected bays and estuaries were sampled along the Atlantic and Gulf of Mexico coasts and in southern California along the Pacific coast of the United States. The individual survey areas ranged in size from <1.0 km2 to over 550 km2. Col lectively, approximately 2532 km2 were sampled in the 22 surveys. Toxicity was observed in the amphipod survival tests of bulk sediments in approximately 10.9% of the combined area. These data suggest that acute toxicity as measured with adult crustaceans was restricted to small portions of these urbanized estuaries, principally maritime harbors and industrial ized bayous and waterways. Toxicity was much more pervasive in the tests of solvent extracts and 100% porewater, indicating that approximately 61% and 43%, respectively, of the combined areas sampled were toxic. The spatial extent of toxicity decreased to 11% and 5% in tests of 50% and 25% porewater, respectively. In most areas each test indicated different patterns in toxicity, and consequently, the concordance in estimates of toxicity among different tests was very small. Estimates of the spatial extent of toxicity probably would differ if tests were performed elsewhere and/or with different organisms.

A survey of the toxicity of sediments throughout the Tampa Bay estuary was performed as part of the National Oceanic and Atmospheric Administration's National Status and Trends Program. The objectives of the survey were to determine the spatial extent and severity of toxicity and to identify relationships between chemical contamination and toxicity. Three independent toxicity tests were performed: a 10‐d amphipod survival test of the whole sediments with Ampelisca abdita, a sea urchin fertilization test of sediment pore water with Arbacia punctulata, and a 5‐min Microtox® bioluminescence test with solvent extracts of the sediments. Seventy‐three percent of the 165 undiluted sediment pore‐water samples were significantly toxic relative to reference samples with the sea urchin fertilization test. In contrast, only 2% of the 165 samples were significantly toxic in the amphipod tests. The causes of toxicity were not determined. However, concentrations of numerous trace metals, pesticides, polychlorinated biphenyl (PCB) congeners, polycyclic aromatic hydrocarbons (PAHs), and ammonia were highly correlated with pore‐water toxicity. Concentrations of many substances, especially total dichlorodiphenyltrichloroethanes (DDTs), endrin, total PCBs, certain PAHs, lead, and zinc, occurred at concentrations in the toxic samples that equaled or exceeded concentrations that have been previously associated with sediment toxicity.

Abstract-A survey of the toxicity of sediments throughout the Tampa Bay estuary was performed as part of the National Oceanic and Atmospheric Administration's National Status and Trends Program. The objectives of the survey were to determine the spatial extent and severity of toxicity and to identify relationships between chemical contamination and toxicity. Three independent toxicity tests were performed: a 10-d amphipod survival test of the whole sediments with Ampelisca abdita, a sea urchin fertilization test of sediment pore water with Arbacia punctulata, and a 5-min Microtox bioluminescence test with solvent extracts of the sediments. Seventy-three percent of the 165 undiluted sediment pore-water samples were significantly toxic relative to reference samples with the sea urchin fertilization test. In contrast, only 2% of the 165 samples were significantly toxic in the amphipod tests. The causes of toxicity were not determined. However, concentrations of numerous trace metals, pesticides, polychlorinated biphenyl (PCB) congeners, polycyclic aromatic hydrocarbons (PAHs), and ammonia were highly correlated with pore-water toxicity. Concentrations of many substances, especially total dichlorodiphenyltrichloroethanes (DDTs), endrin, total PCBs, certain PAHs, lead, and zinc, occurred at concentrations in the toxic samples that equaled or exceeded concentrations that have been previously associated with sediment toxicity.