Applications of aquatic and sediment toxicity testing in situ

Bioassays using caged fish, bivalves, and other macroinvertebrates (in situ toxicity tests) supplement traditional eco-toxicological approaches such as laboratory toxicity tests and evaluation of benthic invertebrate or fish communities. In situ toxicity tests incorporate complex site-specific conditions (e.g., suspended solids, light, dissolved oxygen, pH, salinity, and temperature), which may alter contaminant toxicity and/or bioavailablity. Fish and bivalves have been used most frequently due to technology transfer from aquaculture methodologies and other concerns about these animal groups. More recently, laboratory methods for testing commonly used macroinvertebrates (e.g., cladocerans, amphipods, and midges) have been developed for use in the field. A concise summary of the uses and applications of in situ testing (e.g., stressor identification, chronic bioaccumulation studies, stormwater runoff assessment, evaluation of photoinduced toxicity at PAH-contaminated sites, and assessment of episodic acidification of streams) is provided.