2023 Early Hearing Detection & Intervention Conference
March 5-7, 2023 • Cincinnati, OH
5/23/2019 | 11:15 AM - 11:30 AM | FISH INVADERS INVOKE TROPHIC NICHE SHIFTS IN NATIVE SPECIES | 250 DE
FISH INVADERS INVOKE TROPHIC NICHE SHIFTS IN NATIVE SPECIES
Past and ongoing species introductions to freshwater ecosystems have made novel assemblages increasingly common. In these assemblages, an ongoing challenge is identifying and predicting non-native species food-web impacts to address the management of vulnerable species. Using a gradient of invasion from unimpacted native-only assemblages to assemblages completely replaced by non-native species, our objective was to determine how trophic niche and resource use of native and non-native fishes respond in each other’s presence. We then tested for recovery in the patterns of trophic niche shifts before and after non-native species removal managed by the local state agency. We used natural abundance Carbon and Nitrogen stable isotope data to evaluate species niches in the Bill Williams watershed, Arizona, USA. Circular statistics and Bayesian Standard Ellipse Areas helped us examine shifts in trophic resource use and overlap. In the presence of non-native species, native species had significant shifts in directionality toward lower trophic level and different basal resources, but non-native species showed variable and non-significant responses to the presence of native species. Native species with the highest overlap with non-native species niches had the highest potential for recovery after non-native species removal.
- Food Webs
- Fish
- Isotope
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Presenters/Authors
Jane Rogosch
(), University of Washington, jfencl@uw.edu;
ASHA DISCLOSURE:
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Julian Olden
(), University of Washington, olden@uw.edu;
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