Welcome to the interactive web schedule for the 2018 Midwest Fish & Wildlife Conference! For tips on how to navigate this site, visit the "Helpful Info" section. To return to the main Conference website, go to: www.midwestfw.org.
Back To Schedule
Tuesday, January 30 • 10:40am - 11:00am
ASIAN CARP & OTHER AQUATIC INVASIVES: Habitat Quality Explains Population Collapse of Invasive Rusty Crayfish in Northern Wisconsin Lakes

Sign up or log in to save this to your schedule, view media, leave feedback and see who's attending!

AUTHORS. Eric R. Larson, University of Illinois at Urbana-Champaign; Timothy A. Kreps, Bridgewater College; Brett W. Peters, University of Notre Dame; Jody A. Peters, University of Notre Dame; David M. Lodge, Cornell University

ABSTRACT. The abundance and impacts of nonindigenous species often change through the course of invasion as they alter food webs and ecosystems, but most research occurs at temporal and spatial scales that are too short and small to capture these important dynamics. For example, the prevalence of population "busts" in which established invaders decline or even disappear over time is difficult to evaluate without long-term monitoring of invasions. We used over 40 years of data (1973-2017) on the abundance of invasive rusty crayfish in 17 Vilas County, Wisconsin, lakes to evaluate the long-term fate of these populations, including whether or not some lakes have experienced busts of previously abundant rusty crayfish. Although rusty crayfish populations have remained high in some lakes, seven lakes (41%) have experienced significant, sustained declines of rusty crayfish from earlier peaks. Interestingly, these collapse lakes have less rock substrate than lakes where rusty crayfish populations have not declined. We propose that in the absence of this preferred rocky substrate, rusty crayfish populations destroy the aquatic macrophytes providing them shelter from fish and other predators, eventually resulting in a feedback in which rusty crayfish populations decline under predation pressure. We conclude by discussing other mechanisms that could contribute to rusty crayfish population declines and identifying research needs into patterns of collapse for this and other invasive species.

Tuesday January 30, 2018 10:40am - 11:00am CST