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Relationships Between Exceedences of Metals Criteria and Community Metrics in Mining Impacted Streams
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| Abstract: | To use bioassessments to diagnose specific environmental stressor gradients in streams, a better understanding is needed of the relationships between community metrics and ambient criteria. However, this relationship is not necessarily simple, because metrics generally assess measurement endpoints at the community level of biological organization, while ambient criteria are based on measurement endpoints at the individual level. For metals, the relationship is further complicated, because their bioavailability and toxicity are related to other chemical variables. Currently, freshwater water quality criteria for many metals are related to hardness. In 1993 and 1994, USEPA conducted a Regional Environmental Monitoring and Assessment Program (REMAP) survey of 105 second to fourth order streams in the Southern Rockies Ecoregion of Colorado. This ecoregion contains about 95% of the mineralized portion of the Rocky Mountains, and mine of metals over the past centruy has resulted in stream contamination from both active and inactive mining sites. The surveys collected fish and macroinvertebrate assemblages, physical habitat, and sediment and water chemistry and toxicity. We characterized streams as metals-contaminated based on exceedence of hardness-corrected metals criteria for cadmium, copper, lead and zinc and on water column toxicity tests (48-hour Pimephales promelas and Ceriodaphnia dubia survival). Then, macroinvertebrate and fish metrics were compared among contaminated and uncontaminated sites to determine those metrics most sensitive to metal contamination. These survey data provide a framework for assessing diagnostic community metrics for specific environmental stressors. |
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| Citation: | Lazorchak, J. M., M. B. Griffith, and A. T. Herlihy. Relationships Between Exceedences of Metals Criteria and Community Metrics in Mining Impacted Streams. Presented at Hardrock Mining Conference, Westminster, CO, May 7-9, 2002. |
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| Contact: |
Linda Ransick - (513) 569-7395 or ransick.linda@epa.gov
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| Division: |
Ecological Exposure Research Division |
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| Branch: |
Molecular Ecology Research Branch |
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| Product Type: |
Abstrct/Oral |
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| Presented: |
05/07/2002 |
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