Impacts of an invasive mussel on the trophic profile and diet of the threatened False Map turtle
invasive mussel, invasive species, turtles, Missouri River
Non-native and invasive species are a widespread phenomenon that can cause disruption of local ecosystem functions. Of interest in this study is the modification of the trophic structure of the Missouri River system, caused by invasive zebra mussels. To investigate this modification, multi-tissue (claw and blood) stable isotope analysis will be used to assess isotopic niche trajectories of the threatened False Map turtle in South Dakota, and to reveal potential diet shifts under different zebra mussel invasion intensities. I expect to find that communities with a higher zebra mussel invasion intensity will have a different isotopic structure than those with low invasion intensity. Furthermore, I expect turtles in low intensity invasion areas to have a more varied diet, with greater δ15N values reflecting that variety, and δ13C profiles that are not very similar to any specific prey item. Conversely, in areas with a high invasion intensity, I expect to find less enriched δ15N values, reflecting a shift in foraging strategies, perhaps due to a change in prey availability under highly invaded conditions. Additionally, the expected δ13C profiles in turtles where invasion rates are high would be reflective of their primary prey item, and therefore may resemble the δ13C values of zebra mussels from the area. This study will provide insight on if and how invasive species alter local ecosystem functions and provides an opportunity for further study into impacts at other trophic levels, as well as investigations on potential cascading effects of a species shifting in trophic position.
Baker, Jami, "Impacts of an invasive mussel on the trophic profile and diet of the threatened False Map turtle" (2021). IdeaFest. 359.