• Sediment toxicity;
  • Benthic infauna


Autesedimenttoxicity testshave become important in regulatory, monitoring, and scientificprograms, partly because it has been assumed that they are indicative of ecological damage to benthic infaunal resources. Data from tests of sediment toxicity and measures of benthic community structure were examined from > 1,400 saltwater samples to determine the relationships between acute toxicity and changes in the abundance and diversity of infauna resources. Data were compiled from studies conducted along portions of the Atlantic, Gulf of Mexico, and Pacific coasts of the United States. There was considerable variability among the data sets in the relationships between laboratory results and benthic measures. However, in 92% of the samples classified as toxic, at least one measure of benthic diversity or abundance was <50% of the average reference value. In 67% of these samples, at least one measure of benthic infauna abundance or diversity was <10% of average reference conditions. No amphipods were found in 39% of samples that were classified as toxic, whereas amphipods were absent from 28% of the nontoxic samples. In many survey areas, the abundance of crustaceans (notably the amphipods) decreased in the infauna as amphipod survival decreased in the laboratory tests. There appeared to be a break point in the data indicating that, generally, amphipod abundance in the field was lowest when survival in the laboratory tests dropped below 50% of controls. Based on the weight of evidence from all the data analyses, we conclude that ecologically relevant losses in the abundance and diversity of the benthic infauna frequently corresponded with reduced amphipod survival in the laboratory tests.