Great Lakes Restoration Initiative Funds National Grass Carp Report

February 25, 2015

Katie Steiger-Meister, 612-713-5317,

In an effort to prevent the illegal or unintentional release of grass carps into the Great Lakes, the U.S. Fish and Wildlife Service requested the Mississippi Interstate Cooperative Resource Association to examine commercial grass carp production in the United States. The final report contains eight recommendations from MICRA on how to potentially improve grass carp production, certification, shipping, stocking and regulation. The report was funded by the Great Lakes Restoration Initiative.

Grass carps, an invasive species of Asian carp, were imported in 1963 for their ability to consume nuisance aquatic vegetation. Eventually escaping into the wild, grass carp populations were first reported in the Mississippi River Basin as early as 1970. Today, grass carps are widely distributed throughout the country’s waterways including the Great Lakes, with the exception of Lake Superior. To date, the grass carps found in the Great Lakes are not believed to be part of a self-sustaining population.

Not all of the grass carps found in the wild are able to reproduce. A decade after grass carps were first commercially produced in the United States, many states began to ban the sale and stocking of fertile grass carps. In their place, they required hatcheries to produce only sterile grass carps, referred to as triploid. The U.S. Fish and Wildlife Service runs the National Triploid Grass Carp Inspection and Certification Program to ensure that grass carp producers who voluntarily participate in the program are selling sterile fish.

MICRA’s report concludes 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 in the Great Lakes. The views and conclusions contained in the report are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. Government or the individual state agency members of MICRA.

To read the complete report, please visit: