6th Annual Judith Ramaley Celebration of Research and Creative Scholarship
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Poster #78 Assessment of the Rush-Pine Creek Watershed, Southeastern Minnesota, Using Fish and Benthic Invertebrate Indices of Biotic Integrity Darcy E. Mundahl Faculty Mentor: Neal Mundahl The Rush-Pine Creek watershed has been impacted by poor agricultural land use in the past, and recently experienced a catastrophic, 1000-year flood event. The objectives of this study were to assess fish and benthic invertebrate assemblages at eight coldwater stream sites in the Rush-Pine Creek watershed, and compare them to three other stream sites outside the watershed to gain perspective on the health of aquatic communities within the watershed. Kick samples of invertebrates were collected and sorted, and communities (35 different taxa) were compared among sites using the Benthic Invertebrate Index of Biotic Integrity. Fish assemblages were sampled using a backpack electrofisher, and communities (18 species of fishes) were compared among sites using the Coldwater Index of Biotic Integrity. Invertebrate IBI scores generally were low (most sites rated poor or fair), with the highest scoring sites in the lower reaches of the Rush-Pine watershed. Low scores were attributed to deficiencies in number of stonefly species, long-lived species, intolerant species, and predator species. Fish scores were slightly higher (most sites rated fair or good), with the highest scoring sites in the upper reaches and tributaries of the Rush-Pine Watershed. Most sites had acceptable numbers of total species and coldwater species, and acceptable percentages of coldwater and intolerant species, but had an overabundance of white suckers and were deficient in percent salmonids as brook trout. These differences in scores suggest that the Rush-Pine has been impaired, and while stocking efforts may have improved fish assemblages, invertebrate assemblages have not yet recovered. |
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