Species control for managing thermal guild interactions in warming food webs

Abstract

To promote sustainable fisheries under climate change, fisheries managers must apply appropriate adaptation measures. However, little is known about how species interactions shift with climate change and the potential effectiveness of such adaptation measures. Here, we modeled the application of a species control measure in a lake ecosystem using a temperature-dependent food-web model containing different thermal guilds. A warm-adapted predator (bass, Micropterus spp) was removed to locally mitigate undesirable effects of climate warming on a cool-adapted species (walleye, Sander vitreus). Nevertheless, a warming-induced thermally mediated trophic cascade can lead to expected and unexpected outcomes, with bass removal depending on food-web linkages. With low levels of bass predation on juvenile walleye, walleye persist in warmer temperatures when bass are present (not controlled) than when bass are absent (controlled). Therefore, we encourage managers to use caution and consider various scenarios of food-web changes, to determine when species control may be effective for climate adaptation.