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Linkages between benthic macroinvertebrate assemblages and landscape stressors in the US Great Lakes
Citation:
Scharold, J., P. Yurista, AND J. Kelly. Linkages between benthic macroinvertebrate assemblages and landscape stressors in the US Great Lakes. IAGLR Conference, Burlington, VT, May 25 - 29, 2015.
Impact/Purpose:
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Description:
We used multiple linear regression analysis to investigate relationships between benthic macroinvertebrate assemblages in the nearshore region of the Laurentian Great Lakes and landscape characteristics in adjacent watersheds. Benthic invertebrate data were obtained from the 2010 National Coastal Condition Assessment, a probability-based survey of the Great Lakes US nearshore zone (0-30m depth and within 5km from shore). Ponar grabs were collected at 306 sites distributed across all 5 Lakes. Backward stepwise regressions across sites revealed significant correlations of several benthic invertebrate assemblage metrics with landscape measures of anthropogenic stress in adjacent coastal watersheds. At a basin-wide scale, taxa richness, the Shannon diversity index, the oligochaete trophic index, and densities of chironomids and Diporeia were significantly related to agricultural activity in basin watersheds. Other significant landscape-level explanatory variables included human population density, land cover/land use, point source inputs, and soils. Study results provide evidence that benthic macroinvertebrate assemblages in the nearshore zone of the Great Lakes are responsive to landscape-derived stressors emanating from the adjacent watersheds.