Bighead and silver carp (Asian carps) threaten to invade the Great Lakes and disrupt aquatic food webs and fisheries through their consumption of plankton and detritus in lower trophic levels. Asian carps can cause shifts in phytoplankton and zooplankton species composition and abundances resulting in changes up the food web. In rivers and lakes in North America, Asia and Europe, the introductions of Asian carps have resulted in the decline of many native fish species, with planktivorous larval, juvenile or adult fish being particularly affected.
We have modeled the potential risk of Asian carps to Great Lakes food webs using 3 different food web models:
- Ecopath with Ecosim – EwE
- Individual based bioenergetics model – IBM
- Atlantis Ecosystem model
Our past model simulations of the potential for Asian carps to grow and impact 5 Great Lakes habitats (Lake Erie, Lake Ontario, Saginaw Bay, main basin Lake Huron, main basin Lake Michigan) indicates that if Asian carps reach a high biomass, there could be negative consequences for some fishery species (see Figure below). Potential growth and impacts of Asian carp are positively affected by lake productivity, but differ slightly depending upon the resident fish community and their diet preferences in each lake.
Currently, this project is developing and applying the IBM model to simulate dynamics of grass carp, bighead and silver carp, 4 resident fish species (including walleye, yellow perch, gizzard shad, smallmouth bass), and multiple prey biomass groups in the Maumee River, OH and Lake Erie’s western basin. Grass carp currently are reproducing in the Maumee River and bigheaded carps may find suitable habitat in the river for reproduction and establishment if introduced. The project will simulate a range of targeted harvests of Asian carps to help inform current management and control efforts.
Funding
FY 2023: $110,800
FY 2022: $110,800
FY 2021: $110,800
FY 2020: $105,000
Contacts: Ed.Rutherford@noaa.gov and Doran.Mason@noaa.gov