Spatial variation of trophic transfer efficiency in a large lake

Lake Erie is among the largest lakes on the planet and contains three basins that vary in limnological and biological characteristics. Here, we investigate how the structure and function of the Lake Erie food web varies spatially using mass-balanced, current state Ecopath models representing the whole lake and each of its three major basins (west, central and east) between 2016-2020. Overall species composition and trophic structure were similar between basins and the whole lake, but trophic transfer efficiency was highest in the eutrophic west basin (8.1%) and lowest in the more oligotrophic east basin (7.0%), which was likely related to the availability of nutrients (eutrophic vs. oligotrophic) and resources within each. This modelling exercise has demonstrated that while the community composition of the Lake Erie food web is similar between basins, differences in their trophic structure have important implications for ecosystem management in Lake Erie.