Guild Based Habitat Use and Environmental Drivers of Fish Community Change in the Upper Mississippi River System

The community of fish found in stretch of a river is highly dependent on the environmental conditions that the stretch experiences. Species with similar life history traits will generally be found in similar habitat whereas opposing life history traits will warrant different habitat preferences. These life history-habitat use relationships have been forged over centuries through evolution but anthropogenic influences have rapidly changed river conditions, threatening to disrupt the delicate balances struck by fishes and their habitats. Invasive species, changes to physical habitat, and climate changes have all dramatically altered the available habitats within the Upper Mississippi River System and fish communities have changed with them. Long Term Resource Monitoring Program data was used to evaluate the habitats used by different guilds and the drivers of temporal community change. To evaluate the habitats used by different feeding and reproductive guilds we used non-metric multidimensional scaling to ordinate habitat data for representative fish species belonging to each guild and a one-way ANOVA was used to find significant difference in the scores of the groups. Environmental drivers of temporal community change were evaluated with redundancy analysis on annual fish communities of each field station individually.