AUTHORS: Kassidy Frame, Department of Natural Resource Management, South Dakota State University, Brookings, South Dakota; Richard Erickson, U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, Wisconsin; Steve Chipps, U.S Geological Survey, South Dakota Cooperative Fish and Wildlife Research Unit, Department of Natural Resource Management, South Dakota State University, Brookings, South Dakota; Alison Coulter, Department of Natural Resource Management, South Dakota State University, Brookings, South Dakota
ABSTRACT: In the Mississippi River, invasive bigheaded carp (Hypophthalmichthys spp.) can compete with native planktivores, such as Gizzard Shad (Dorosoma cepedianum) and Paddlefish (Polyodon spathula), by altering plankton and zooplankton composition and abundance. The current management strategy is targeted harvest of adult carp using 75-150 mm mesh gill nets and electrofishing with the goal of reducing the biomass of invasive carp and restoring normal ecosystem function. The harvest of invasive carp is limited to adult individuals, but by using less selective removal methods, such as dozer trawls or seines to select for smaller carp, the effect of invasive carp on the ecosystem could be reduced more efficiently. EcoPath with Ecosim (EwE) is a model that can be used to explore changes in biomass of different community groups (e.g. zooplankton, native fishes) after removal of an invasive species such as bigheaded carp. The objective of this study is to implement an EwE model for Pool 26 of the Mississippi River to assess the ecosystem response to the removal of juvenile only, adult only, and combined removal of bigheaded carp. The use of an EwE model in the Mississippi River is a cost-effective method to improve management of invasive carps by evaluating the ecosystem effect of varying removal scenarios and would complement on-going population models such as the SEICarP model.
