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Communication at the NABS Annual meeting, Keystone, 2000
(496) EFFECTS OF ROTENONE ON AQUATIC INVERTEBRATE COMMUNITIES IN PRAIRIE WETLANDS.
C.L. Melaas1, K.D. Zimmer1, M.G. Butler1, and M.A. Hanson2. 1Department of Zoology, North Dakota State University, Fargo, ND 58105, 2Wetland Wildlife and Populations Research Group, Minnesota Department of Natural Resources, Bemidji, MN 56601
We assessed the impact of rotenone (a fish toxicant) on invertebrate communities in wetlands by comparing four wetlands treated with rotenone to four control wetlands in the fall of 1998. We also assessed recovery of the invertebrate communities by sampling the same wetlands throughout the summer of 1999. Invertebrates were sampled in both the water column and sediment in each wetland. Results for invertebrates in the water column showed that the abundances of amphipods, cladocerans, copepods, leeches, and insects (excluding adult hemipterans and coleopterans) were significantly reduced immediately after application of rotenone. In contrast, rotenone had little impact on benthic invertebrates, as sediment samples indicated that only amphipods were affected significantly by the chemical. However, recovery of the invertebrate communities was rapid, as no significant differences were detected between control and treated wetlands in May of 1999. Our results indicate that rotenone has short-term impacts on the abundance of several taxonomic groups of aquatic invertebrates, and that infaunal benthic invertebrates are less susceptible to affects of rotenone than are nektonic forms. Application of rotenone does not appear to have any long-lasting effects on invertebrate abundance.
Presented at 1:00 PM on Wednesday, May 31, 2000 in Ecotoxicology / Toxicity Testing
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