Toxicity Assessment of Coastal Sediments Using Marine Fish

Abstract

  Anthropogenic substances reach sea areas, absorb particles and finally pile up on sediments. Although previous studies investigated the distribution of pollutants and detected a high concentration of pollutant residues in Japanese coastal areas, the effects of these residues on benthic organisms have been almost unknown. In fact, methods to assess sediment toxicity have not been established, and it is not easy to assess the toxicity of sediments collected from the sea bottom. In this study, we worked to assess the maximum impact of toxic sediments on benthic organisms by exposing marine medaka to extracts from sediments collected from five sites in Tokyo Bay, Japan. The results showed that sediments collected at two sites caused fatal effects on marine medaka. Furthermore, marine medaka were also exposed to three fractionation processes of varying polarity extracts. The results of these exposure tests indicated the possibility that such sediment extracts may have caused antagonistic effects.