QUANTIFYING RELATIONSHIPS BETWEEN TAILWATER MACROINVERTEBRATE DIVERSITY AND SECONDARY PRODUCTION
Tailwater fisheries are frequently food limited due to both low macroinvertebrate diversity and food resources that are not readily available or optimal. Improvements to the foodbase often involve attempts to increase production of existing prey or to diversify the foodbase, or both. The latter approach assumes that a more diverse foodbase will be more temporally stable and productive, thus supporting greater fish densities or biomass. However, the relationship between diversity and secondary production has not been extensively studied for freshwater macroinvertebrates, and the few studies that exist have been limited to small, relatively un-impacted systems. We used a spatial gradient in diversity among long-term monitoring stations on the Green River below Flaming Gorge Dam, Utah to quantify relationships between macroinvertebrate diversity and secondary production. We calculated secondary production at each station on a monthly basis for one year and compared the results to metrics of diversity. We hypothesize that the predominance of high density, multivoltine taxa immediately below the dam will result in no net change in secondary production despite downstream increases in diversity. Results will refine our understanding of biological controls on tailwater fisheries management in regulated western rivers.
Matt Schroer (Primary Presenter/Author), BLM/USU National Aquatic Monitoring Center, Department of Watershed Sciences, Utah State University, firstname.lastname@example.org;
Scott Miller (Co-Presenter/Co-Author), BLM/USU National Aquatic Monitoring Center, Department of Watershed Sciences, Utah State University, email@example.com;