SAMPLING BENTHIC COMMUNITIES FOR SEDIMENT TOXICITY ASSESSMENTS USING GRAB SAMPLERS AND ARTIFICIAL SUBSTRATES

In this study we compared macrobenthic communities collected from the Saginaw River (Michigan), Buffalo River (New York), Indiana Harbor (In diana), Little Scioto River (Ohio), and Milltown Reservoir (Montana) a t the same locations using artificial substrates and grab samplers. Ol igochaete worms (Limnodrilus hoffmeisteri) were the predominant benthi c organisms in sediment samples collected with grab samplers. Artifici al substrates also collected nothing but oligochaetes, but only at the stations with the most contaminated sediment in Indiana Harbor and th e Little Scioto River. Artificial substrate samples from the Saginaw R iver, Buffalo River, and Milltown Reservoir generally contained a more diverse assemblage of benthic taxa. Routine assessments of sediment t oxicity based on analyses of benthic macroinvertebrate communities sho uld sample all available benthic habitats. Sediment samples collected with a grab sampler and artificial substrates should both be used for evaluating benthic communities in sediment toxicity assessments.