Archives - Asian Carp

Article Archives/Asian Carp - Grass Carp

Asian Carp - Grass Carp (Part 1 of a 4 part series)

USSFN 8/18/03 - The grass carp or white amur, native to eastern Asia, was first imported into the U.S. in 1963 to aquaculture facilities in Auburn, Alabama and Stuttgart, Arkansas for research in the control of aquatic vegetation. This species typically inhabits large rivers but can be raised in ponds and rice fields; and large individuals are known to consume many pounds of aquatic vegetation in a single day. The first release into open waters occurred as a result of escapement from the Fish Farming Experiment Station in Stuttgart.

By the mid-1960’s the Arkansas Game and Fish Commission was raising the species at a state fish hatchery in Roanoke; and by 1978 Arkansas biologists had stocked the species in more than 100 state lakes. Since that time grass carp have rapidly spread to 45 states through the accidental and intentional, legal and illegal release by numerous state and federal agencies, private groups and individuals. Despite efforts to control the spread of grass carp by stocking individuals thought to be sterile, this large (50+ lbs), elongate, stout-bodied, blunt-headed, pale gray minnow has established itself and is reproducing in the wild. Grass carp began to appear in the catches of Arkansas’ commercial fishermen in the early 1970’s, and by 1976, 25 tons were reported taken statewide.

The species has limited potential as a gamefish, and as a food fish the flesh is often said to be tainted with a strong algal flavor. However, local demand for and acceptance of grass carp is reported to be very high in some markets. Grass carp are regarded as the most palatable of all of the Asian carps. While introduced to consume troublesome aquatic plants, grass carp have been known to clean entire lakes of all aquatic plants, and to then consume organic detritus and animal materials.

Negative impacts on native organisms have been summarized to include: interspecific competition for food with invertebrates (i.e., crayfish) and other fishes; significant changes in the composition of macrophyte, phytoplankton, and invertebrate communities; interference with the reproduction of other fishes; decreases in refugia for other fishes; modification of preferred fish habitats; enrichment and eutrophication of lakes; disruption of food webs and trophic structure; and introduction of nonnative parasites and diseases.

Source: U.S. Fish and Wildlife Service