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EFFECTS OF COPPER ON COMMUNITY, FUNCTIONAL, AND BEHAVIORAL ENDPOINTS IN AN ARTIFICIAL STREAM STUDY
Citation:
ALLEN, JOEL J. AND ET AL. EFFECTS OF COPPER ON COMMUNITY, FUNCTIONAL, AND BEHAVIORAL ENDPOINTS IN AN ARTIFICIAL STREAM STUDY . Presented at SETAC Annual Meeting, Montreal, QC, CANADA, November 07, 2006.
Impact/Purpose:
To inform the public
Description:
A study of the effects of copper on biota and behavioral endpoints was carried out at the U.S. EPA's Experimental Stream Facility (ESF), Milford OH. The objective of the study was to identify relationships between structural (macrobenthos and periphyton indices), functional (interstitial nutrient chemistry), and behavioral (bivalve gape and macroinvertebrate drift) metrics driven by copper exposure. Correlation of bivalve gape with community and functional impacts would support the potential use of such online toxicity monitors in watershed scale early warning systems. Six stream mesocosms were fed raw East Fork of the Little Miami River water. The streams colonized for 2 weeks followed by a 3 week dosing with nominal copper concentrations of 0, 6.25, 12.5, 25, 50, and 100μg/L copper. A concentration dependent response was observed in the bivalve metrics acute gape response and chronic measures (amplitude, frequency, and magnitude of group gape patterns). An apparent concentration dependent response was observed in periphyton biomass and chlorophyll a content after two weeks of exposure. Macrobenthos differences were observed at three weeks. Results suggest a significant positive correlation between interstitial dissolved reactive phosphorus (DRP) and copper dose. Interstitial ammonium, nitrate-nitrite, total nitrogen, and total phosphorus appeared unaffected. A negative relationship between chlorophyll a content and copper concentration was observed indicating the DRP(suspected limiting nutrient) trend may represent a decrease in biotic uptake. This potential effect of metal pollution on stream nutrient source-sink strength, and may be an important consideration for modeling the dynamics of watershed scale nutrient fluxes. This study demonstrates the close relationship between community structure, function, and group behaviors under stress. It also provides support to the use of online toxicity monitors as indicators of toxic impacts at the community level.