Our research suggests that investigators must play close attention to toxicity
test conditions in the laboratory in order to accurately predict the risks
that water-borne contaminants may pose to aquatic organisms. The
high concentrations of organic matter in stormwater runoff may bind up
some of the toxic contaminants in the water and make them less available
to suspension feeders floating in the lake water. However, bottom-dwelling
invertebrates that live among the settled particles and feed on them may
have a greater exposure to contaminants on the lake floor.