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I'm a fisheries ecologist interested generally in how global change (anthropogenic and climate stressors) impact recreational fisheries dynamics and fish biology. I completed my doctorate at the University of Notre Dame and my undergraduate at Emory University. In my free time I enjoy camping, fishing, and trying new restaurants.
Denver Link¹ and Gretchen Hansen¹
1. University of Minnesota, Department of Fisheries, Wildlife and Conservation Biology, Saint Paul, MN 55108
Species assemblages of ecological communities arise from a combination of functional and physiological diversity amongst species and environmental variability. Climate change and other dynamic global changes threaten to increase environmental extremes and shift resource usage within ecosystems. Freshwater ecosystems are especially vulnerable to increases in air temperature and precipitation which directly impact surface water temperatures and dissolved oxygen. Changes in the abiotic conditions of freshwater ecosystems may increase competition of coexisting fish species due to these shifts in thermal habitat availability. To quantify how species across thermal guilds use resources within lake environments and if niche partitioning can be predicted by fish physiology, abiotic environmental factors, and the number of co-occurring species, we examined stable isotope ratios across 35 Minnesota lakes. Stable isotope C and N ratios can display basal resource usage and trophic position within lakes due to the C enrichment of benthic production compared to pelagic production and N enrichment increases between prey and predator up food webs. We calculated community and species specific niche areas using trophic position and littoral reliance Bayesian model estimates of fish across 3 different thermal guilds (cold, cool, and warm water). In addition, we compared generalized linear models to test for the relationship between niche breadth, fish physiology, species coexistence, and abiotic lake characteristics.