Title
he Environmental Integrity of Benthic Macroinvertebrate Communities of the Upper Clark Fork River 1991-1998
Abstract
The benthic macroinvertebrate (BMI) communities of the Upper Clark Fork River (UCFR) Watershed in Montana have been the subject of an extensive long-term monitoring program by the State of Montana. However these investigations have not included a characterization of habitat at sampling stations in the Clark Fork River or reference streams. Additionally, the temporal patterns of annual average dissolved metals concentrations and how they co-vary with community data has not been presented for sites with co-located average water chemistry measurements. Biomonitoring reports have implied effects from historic mining and smelting activities based on a biotic index that includes multiple community metrics with impairment defined relative to scores observed at a reference stream (Blackfoot River). In this paper the differences in habitat between the reference stream and biomonitoring sites in the Clark Fork River Watershed are documented. When compared with UCFR sites, reference sites were found to differ significantly and ecologically in habitat features such as embeddedness and riffle and pool-run pebble count substrate particle size distribution. Macroinvertebrate community measures (taxa richness, EPT richness and abundance) were not correlated with annual average dissolved or total metals levels or with available USGS invertebrate tissue monitoring data for sites on the UCFR during the period of record 1991-1998. These data suggest that macroinvertebrate communities of the UCFR are not significantly affected by metals exposures.
Editor’s note: I suggested that the final sentence read:
This correlation analysis provides no evidence that UCFR macroinvertebrate communities are affected by metals exposure.
but the author and I have agreed to disagree on this.
Start Date
14-4-2000 12:00 AM
End Date
14-4-2000 12:00 AM
Document Type
Poster
he Environmental Integrity of Benthic Macroinvertebrate Communities of the Upper Clark Fork River 1991-1998
The benthic macroinvertebrate (BMI) communities of the Upper Clark Fork River (UCFR) Watershed in Montana have been the subject of an extensive long-term monitoring program by the State of Montana. However these investigations have not included a characterization of habitat at sampling stations in the Clark Fork River or reference streams. Additionally, the temporal patterns of annual average dissolved metals concentrations and how they co-vary with community data has not been presented for sites with co-located average water chemistry measurements. Biomonitoring reports have implied effects from historic mining and smelting activities based on a biotic index that includes multiple community metrics with impairment defined relative to scores observed at a reference stream (Blackfoot River). In this paper the differences in habitat between the reference stream and biomonitoring sites in the Clark Fork River Watershed are documented. When compared with UCFR sites, reference sites were found to differ significantly and ecologically in habitat features such as embeddedness and riffle and pool-run pebble count substrate particle size distribution. Macroinvertebrate community measures (taxa richness, EPT richness and abundance) were not correlated with annual average dissolved or total metals levels or with available USGS invertebrate tissue monitoring data for sites on the UCFR during the period of record 1991-1998. These data suggest that macroinvertebrate communities of the UCFR are not significantly affected by metals exposures.
Editor’s note: I suggested that the final sentence read:
This correlation analysis provides no evidence that UCFR macroinvertebrate communities are affected by metals exposure.
but the author and I have agreed to disagree on this.