Zach Maguire
Evaluating the influence of tributary confluences on macroinvertebrate and trout populations in the Madison River, Montana
Changes to climate, land use, and flow regimes are altering macroinvertebrate and fish populations in river ecosystems worldwide and are the hypothesized mechanisms for the decline of these populations in the Madison River, Montana. Tributaries can alter the biotic and abiotic characteristics of mainstem rivers where they merge, but little is known about how these areas influence macroinvertebrate drift in the water column and availability of food for fishes in regulated rivers.
Zach Maguire is a Master’s student in the Ecology Department at Montana State University. His research is using field surveys to investigate tributary confluences on the Madison River, specifically documenting how macroinvertebrate community metrics in the benthos and the drift differ between the mouth of tributaries and the mainstem. Additionally, he is quantifying the influence of a suite of abiotic & biotic factors (temperature, sediment size, biofilm, riparian community, etc.) on the macroinvertebrate communities both in the tributaries and the mainstem. Zach will use these data to estimate how much food is available to trout (caloric opportunity) at the mouth of 5 tributaries and to compare availability at locations just upstream compared to just downstream of a tributary confluence.