An adaptive management approach for implementing multi-jurisdictional response to grass carp in Lake Erie

Abstract

The Great Lakes are influenced by established aquatic invasive species (AIS) and the threat of new invaders persists. Grass carp, one of four species commonly referred to as Asian carp, are considered invasive because of their ability to adversely modify aquatic habitat through consumption of aquatic macrophytes. Grass carp have been infrequently detected in the Great Lakes since the mid-1980s. More frequent reports of grass carp captures from commercial fishermen in the early 2010’s elevated the concern of the potential risk of colonization in Lake Erie. This paper provides a case study detailing the development and implementation of a multi-jurisdictional response strategy for grass carp in Lake Erie. To respond to threats of grass carp in Lake Erie, Michigan and Ohio Departments of Natural Resources led targeted responses using a collaborative multi-jurisdictional approach, while simultaneously investing in reducing critical life-history uncertainties to refine strategies in an adaptive and science-based manner. Efforts to address uncertainties about grass carp life history documented spawning in two Lake Erie tributaries. Building on these early responses, the binational Lake Erie Committee developed a five-year adaptive response framework to guide response actions. The collaborative response efforts resulted in the capture and removal of 184 fertile grass carp since 2014, and efforts are ongoing to increase effectiveness of strategies to achieve desired population reduction. Coordinated grass carp response actions under the five-year strategy will continue using adaptive management principles with outcomes providing useful insights for adapting existing response frameworks and more broadly for AIS responses implemented elsewhere.