Assessing Risk of Asian Carp Invasion and Impacts on Great Lakes Food Webs and Fisheries

Bighead and silver carp ('AC') threaten to invade the Great Lakes and disrupt aquatic food webs and fisheries. We used a risk-based bioeconomics model to evaluate the potential impact of AC on food web structure, fish production and fisheries in Lake Erie's central basin, which supports important recreational and commercial fisheries and provides nursery habitats for many ecologically or economically important fishes. We used the Ecopath with Ecosim (EwE) food web model to evaluate AC impacts on Lake Erie's food web. We used data collected from 1994-2005 to configure and balance the food web in Ecopath, then used Ecosim to simulate potential AC impacts on food web structure and fish production under current conditions of nutrient loading, fish stocking and harvest. We quantified uncertainty in Ecopath model inputs using expert judgement solicitation, which was incorporated into Ecosim to evaluate uncertainty in model forecasts. To forecast regional economic impacts of AC invasion, we will create and link a regional economic model (Computable General Equilibrium) to the EwE model. This novel approach will include feedbacks between ecological and economic systems, quantifying the value of ecosystem goods and services.