Although grass carp have been found in every one of the Great Lakes except Superior, resource managers don’t believe that the exotic fish have established a self-sustaining population.
But the Mississippi Interstate Resource Association (MICRA) recently warned that “state grass carp regulations are varied and inconsistent, and a national policy strategy is needed to effectively minimize the risks of additional fertile and sterile grass carp introductions into the Great Lakes.”
MICRA reached that conclusion as result of a study funded by the U.S. Fish and Wildlife Service (FWS) to look at grass carp use, production, and regulations. It also made recommendations to help minimize risk not only to the Great Lakes, but other waters not yet infested by unintentional introductions of this aquatic invader.
Those recommendations include the following:
- Production, shipment, stocking, import, and export of diploid (fertile) grass carp should be prohibited except by licensed facilities.
- States that allow production of triploid (sterile) grass should develop a set of minimum standards, permit requirements, and recordkeeping for diploid broodstock.
- States that allow importation of triploid carp should adopt consistent regulations that allow only FWS-certified fish. Also, increase random inspections and enforcement of regulations in these states.
- FWS should work with states, producers, and other partners to develop testing procedures for quality controls and law enforcement in support of random inspections.
Grass carp, a species of Asian carp, were first imported into the U.S. in 1963 as a tool to manage nuisance aquatic vegetation, including exotic hydrilla, in ponds and impoundments. But flooding allowed many to escape into rivers and streams and, by 1970, they were reported in the Mississippi River basin.