Whitney Nelson ACF Abstract FY11

"Composition and Toxic Sensitivity of Benthic Macroinvertebrate Assemblages in Muskegon Lake, a Great Lakes Area of Concern"

North American Benthological Society Annual Meeting

Whitney A. Nelson and Alan D. Steinman

Benthic invertebrate growth, reproduction, and survival in response to anthropogenic stressors can provide insights into the ecological health of an ecosystem. The current study focuses on Muskegon Lake (Michigan), a coastal drowned river mouth lake that has been listed as a Great Lakes Area of Concern (AOC) because of impairments associated with past industrial activities. Benthic samples were collected 3 times per year, from 2004 through 2010. Samples were analyzed to identify spatial and temporal patterns in the density and diversity of benthic invertebrate populations, as well as to determine if invertebrate community patterns were related to environmental variables. Toxicity was assessed using in situ chambers with sediments from Muskegon Lake, as well as from a nearby control lake, to quantify the direct adverse impact of contaminated sediments on Hyalella azteca and Chironomus tentans . Preliminary results from in situ experiments show no affect of sediments on invertebrate survival. However, analysis of benthic samples shows than in each year between 2004 and 2010, there was an increased percent abundance of predatory chironomids vs. total chironomid population at historically contaminated sites.