Upper Midwest Environmental Sciences Center
Avoidance behavior of ruffe exposed to selected formulations of piscicides
Dawson, V. K., Bills, T. D., and Boogaard, M. A., 1998, Avoidance behavior of ruffe exposed to selected formulations of piscicides: Journal of Great Lakes Research, v. 24, no. 2, p. 343-350.
Ruffe were introduced into Duluth Harbor, Minnesota in the early 1980s, probably by release of ballast water from sea-going freighters. Since then, it has become the most abundant species in the fish community. The sensitivity of ruffe to a number of piscicides has been demonstrated, however, the feasibility of using piscicides to control populations depends on whether ruffe can detect piscicides and move to untreated water, We used a two-choice preference resting system to evaluate avoidance or attraction reactions of ruffe during exposures to the lampricides TFM and bayluscide and the general fish toxicants rotenone and antimycin. We used a second testing system to evaluate the potential for benthic ruffe to move vertically in the water column to avoid piscicides dissolving from experimental bottom-release formulations of bayluscide and antimycin. Near-lethal concentrations of TFM and rotenone tended to repel ruffe. Antimycin and bayluscide did not seem to repel ruffe in the avoidance chamber, but bottom-release formulations (antimycin granules-0.25% a.i. And bayluscide granules-3.2% a.i.) did cause increased swimming and surfacing activity among ruffe in column tests. We conclude that TFM and rotenone could be used to trent entire bodies of water, while bottom-release formulations of antimycin and bayluscide may have more application for treating localized concentrations of ruffe.
Keywords: ruffe, avoidance, attraction, piscicides, formulations, Lake Superior