Title
Half a century of aquatic invertebrate community monitoring data from the Clark Fork River
Abstract
In 1956, prior to construction of the Smurfit-Stone Container kraft paper mill, aquatic invertebrate samples were collected from the Clark Fork River above and below the mill outflow site. Sampling continued through 2009, providing an excellent long-term data set documenting the biotic integrity of this part of the river. A multimetric index was derived for this study, due in part to the need for an analytical tool for larger rivers, as existing tools are developed from and for wade-able streams. The results are presented in decadal segments summarizing river conditions and events. Data from four sampling locations which provide a continuously sampled interval for two sites above and below the mill was statistically evaluated for the period from 1971-2005.
Bioassessment scores show a trend of increasing biotic integrity and habitat conditions throughout the study period. Little difference is noted with this assessment between sites upstream and downstream of the mill outflow. While statistical analysis of data from 1971-2005 did find significant difference between the upstream and downstream sites, temporal differences in the data from year to year was of greater influence on assemblage variation than location. It is suggested that the MVFP index may not be the most ideal analytical tool for larger river systems. Species indicative of either good or bad water quality in third order streams are expected to have different abundance patterns in larger streams. This suggests the need to develop new indices that better measure water and habitat quality in larger river systems.
Start Date
5-3-2010 12:00 PM
End Date
5-3-2010 2:00 PM
Document Type
Poster
Half a century of aquatic invertebrate community monitoring data from the Clark Fork River
In 1956, prior to construction of the Smurfit-Stone Container kraft paper mill, aquatic invertebrate samples were collected from the Clark Fork River above and below the mill outflow site. Sampling continued through 2009, providing an excellent long-term data set documenting the biotic integrity of this part of the river. A multimetric index was derived for this study, due in part to the need for an analytical tool for larger rivers, as existing tools are developed from and for wade-able streams. The results are presented in decadal segments summarizing river conditions and events. Data from four sampling locations which provide a continuously sampled interval for two sites above and below the mill was statistically evaluated for the period from 1971-2005.
Bioassessment scores show a trend of increasing biotic integrity and habitat conditions throughout the study period. Little difference is noted with this assessment between sites upstream and downstream of the mill outflow. While statistical analysis of data from 1971-2005 did find significant difference between the upstream and downstream sites, temporal differences in the data from year to year was of greater influence on assemblage variation than location. It is suggested that the MVFP index may not be the most ideal analytical tool for larger river systems. Species indicative of either good or bad water quality in third order streams are expected to have different abundance patterns in larger streams. This suggests the need to develop new indices that better measure water and habitat quality in larger river systems.