Resource partitioning across a trophic gradient between a freshwater fish and an intraguild exotic

Ecology of Freshwater Fish
By: , and 



The introduction of exotic species has the potential to cause resource competition with native species and may lead to competitive exclusion when resources are limiting. On the other hand, information is lacking to predict under what alternate trophic conditions coexistence may occur. Comparing diets of native yellow perch Perca flavescens and nonindigenous white perch Morone americana, we examined variation in resource partitioning and body condition across a prominent longitudinal nutrient gradient in Lake Erie (north‐eastern United States, Canada). As measured with Analysis of Similarity and Schoener's index, diet similarity declined monotonically from west to east tracking declines in nutrients, productivity and relative abundance of both species. Additionally, diet similarity increased from spring through fall, following seasonal development of stratification and hypolimnetic hypoxia—phenomena which tend to increase spatial overlap between these species. Finally, relative weights of both species peaked in the Central Basin (relative weights > 0.85), which, on average, had intermediate values of prey diversity, ecosystem trophic status and water clarity. Our results highlight that native yellow perch coexist with invasive white perch under a wide range of trophic conditions. Of importance to fishery managers, mesotrophy in the Central Basin correlated with the highest body conditions and intermediate prey resource partitioning, although the effect size was small and variable. While competitive exclusion appears unlikely, the goal of reducing nutrient inputs in Lake Erie could affect not only the distributions of both species but also stakeholder decisions about where to fish.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Resource partitioning across a trophic gradient between a freshwater fish and an intraguild exotic
Series title Ecology of Freshwater Fish
DOI 10.1111/eff.12586
Volume 30
Issue 3
Year Published 2021
Language English
Contributing office(s) Great Lakes Science Center
Description 14 p.
First page 320
Last page 333
Country United States
Other Geospatial Lake Erie
Google Analytic Metrics Metrics page
Additional publication details