Assessment of littoral benthic macroinvertebrate communities of alpine lakes in the Sierra Nevada, USA

M.G. Mehling, S.A. Roark, and J.T. Oris. Center for Environmental Toxicology & Statistics, Miami University, Oxford, Ohio 45056

Benthic macroinvertebrates are used as bioindicators of ecological integrity because they are ubiquitous, diverse, sedentary, and the presence of particular species/taxa/communities reflects the environmental history of an area. Natural variability of substrate, water chemistry, organic matter, predator/prey interactions, and seasons also affect macroinvertebrate communities. Alpine lakes of the Sierra Nevada are ecologically diverse and vary in degree of human impact. Littoral benthic macroinvertebrates were collected from 17 alpine lakes of the Sierra Nevada along a human impact gradient to assess their use as an indicator of ecological integrity. Macroinvertebrates were identified and analyzed with site-, riparian-, in-lake- and catchment-scale variables. Results indicated littoral benthic macroinvertebrate communities differed due to site characteristics and hydrologic regimes. In addition, littoral benthic macroinvertebrate surveys used in combination with other physiological and ecological indicators provided a robust method to assess the human impacts in regions of diverse ecosystems. This study contributes to the overall understanding of anthropogenic impacts on alpine lake ecosystems and assists in refining lake management strategies for alpine lakes of the western United States.