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Thursday, May 29, 2008 - 1:45 PM
585
Climate change and its effect on stream biological communities
Lei Zheng1, Jeroen Gerritsen1, Erik Leppo1, Anna T. Hamilton2, Britta G. Bierwagen3, and Susan P. Davies4. (1) Tetra Tech Inc., 400 Red Brook Boulevard, Suite 200, Owings Mills, MD 21117, (2) Tetra Tech, Inc., 502 West Cordova Road, Suite C, Santa Fe, NM 87505, (3) Global Change Research Program, ORD, U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., NW, MC 8601 P, Washington, DC 20460, (4) Maine Department of Environmental Protection, Augusta, ME 04333
We investigated stream temperature change and its suspected effect on biological communities at regional scales in response to climate change. We randomly selected more than 20 USGS gauge stream stations in the U.S. where long-term data were available and examined the trend of stream temperature change over the last 30 to 40 years. We found that stream temperature has risen during this period. Long term (~25 years) macroinvertebrate and fish community data from four geographic regions (Maine, Utah, North Carolina, and Ohio) were selected to examine the associations between rising temperature and biological communities. Preliminary results indicate that there have been observed shifts in species composition over the period in various ecoregions within these selected states. Before climate change can be inferred as the primary cause, confounding factors must be reduced or eliminated, such as: changes in permitted discharges and effluents, land use changes, hydrological alteration, operational changes in biological monitoring (sampling methods, level of taxonomic identification) and others. Further examination of covariates with temperature is useful to demonstrate that climate change is the direct cause of compositional shift of biological community.
Web Page: climate change, macroinvertebrates, streams, temperature,