A bioassay for the toxicity of sediment to marine macrobenthos [Pollution]

A bioassay has been developed to determine the acute toxicity of the settleable phase of dredged material to the marine benthos. Five benthic invertebrates representing different taxonomic and trophic positions were allowed to acclimate to control (nonpolluted) sediment and were then covered by a layer of either test or control sediment. Mean survival after 10 days of exposure was significantly different from the control for sediment from the Duwamish River (Wash.), Houston Ship Channel (Tex.), Bailey Creek (Va.), and the Raritan River (N.J.), but there was no significant difference for sediment from Coos Bay and the Skipanon River (Oreg.). There were substantial interspecific differences in survival among the five test species. The most sensitive species was the infaunal amphipod, Paraphoxus epistomus.