Madison, Wisconsin: Wisconsin Department of Natural Resources
Noticeable kills of some species of aquatic insects have accompanied periodic lampricide treatments (3-trifluoromethyl-4-nitrophenol; TFM) within the Bois Brule River (Brule River) drainage since 1959. These kills prompted concern among trout anglers and Department of Natural Resources fisheries personnel about the long-term effects of TFM on the aquatic insect community. This concern was heightened during the early 1980s by declines in several of the river's trout populations that use aquatic insects as a food resource. Hence, benthos collections throughout the drainage basin, and drift-net samples from 3 tributaries, were made between November 1983 and July 1988 to document and assess the status of the aquatic insect fauna of this relatively undisturbed, predominately spring-fed river system.