Glacier National Park stream ecological integrity: 2007–2009 status report

Schweiger, E.; Britten, Mike; Borgman, Erin; Sherrill, Kirk

This report provides both high-level summaries and comprehensive detail to meet the needs of its two primary audiences: park resource managers and network scientists. Managers needing a concise overview of results can read the summary condition tables in the Executive Summary and Results sections. Details are available in the narrative and appendices to provide in-depth context and methodological guidance. SEI methods are documented in the Rocky Mountain Network Stream Ecological Integrity Monitoring Protocol. They are derived from well-established and existing methods developed by network partners. The application of a standardized monitoring protocol facilitates comparison of the park’s streams and rivers to those within the same ecoregions as the park. From 2007 to 2009 we sampled 40 stream sites selected from across the park using a random survey design that provides a statistically valid estimate of stream conditions for the park as a whole. In addition, we sampled six “gradient” sites selected subjectively to provide information on stream conditions at heavily disturbed or especially pristine sites. We also surveyed four “sentinel” streams three or four times annually to provide an indication of how stream conditions change over time (the annual monitoring will be reported separately from this survey report). Overall we conducted 75 sample events that included all methods at these sites during the three year period presented in this report. An additional 14 sample events that did not include all methods (i.e., only water chemistry was sampled) were completed over these years. Section 2.1 provides more details and maps of all sample sites and Appendix A contains a map of all sites. The SEI protocol includes a broad spectrum of indicators to help evaluate the ecological integrity of the streams and rivers of Glacier. We include measures of both drivers and stressors and ecological responses such that we better understand the linkages between these and help parks apply these relationships to resource management. Core indicators include multiple measures of water and sediment chemistry (i.e., nutrients, metals, temperature); physical habitat (i.e., substrate composition, riparian cover, channel geomorphology); and community level assays of two important biological communities: macroinvertebrates and algae. The latter provide an integrated aspect for assessing ecological integrity because these organisms respond to environmental conditions over time and space. Overall, the ecological integrity of the majority of the streams and rivers in Glacier was in reference or pristine reference condition in 2007–2009. Macroinvertebrate and diatom communities were largely intact and sometimes included previously undescribed species, suggesting a high level of biological distinctiveness. Localized impacts from sediments, nutrients, or metals were minor. Front country streams, including select tributaries to the North Fork of the Flathead (Coal Creek, Big Creek, anc Canyon Creek) Rubideau Creek near park headquarters, Divide Creek near St. Mary, and Railroad Creek near East Glacier had relatively reduced eco-logical condition, potentially driven by human disturbance.

Glacier National Park stream ecological integrity: 2007–2009 status report

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