Extent and Impact of Infestation

Asian carp were introduced into the US in 1973 for use in aquaculture ponds but were then accidently released and found their way into the Mississippi River drainage and surrounding tributaries. The Mississippi River system acted like a giant freshwater highway that gave invasive Asian carp access to many of the country’s rivers and streams. They are now established in 48 US states. They are now known to be well-established in the Mississippi River basin and its tributaries in extremely high numbers. Bighead, silver, and grass carp have been captured in watersheds from Louisiana to South Dakota, Minnesota, and Ohio. Grass carp are known to be established in at least one watershed in Texas, and may be established elsewhere. Grass carp have been captured in all of the Great Lakes except Lake Superior but so far, no evidence indicates a reproducing population. No silver carp or black carp have yet been found in any of the Great Lakes. Silver carp are not present in Canada. Common carp, which were introduced into the US much earlier, are abundant throughout the Great Lakes and many other North American lakes, but are not considered invasive.

Asian carp are fast-growing and prolific feeders that out-compete native fish and leave a trail of environmental destruction in their wake. Asian carp have been associated with significant changes to resources such as the zooplankton and fish communities. The transformation of native aquatic communities results in the intrinsic loss of natural capital and enjoyment of natural areas. The black carp feeds on native mussels and snails, some of which are already endangered. Grass carp can alter the food webs of a new environment by altering the communities of plants, invertebrates, and fish. Bighead and silver carp feed by filtering plankton from the water. Their larvae and juveniles feed on zooplankton while the larger carp feed on phytoplankton only, both of which are necessary for native larval fish and mussels.[9] The extremely high abundance of bighead and silver carp has caused great concern because of the potential for competition with native species for food and living space. Because they are filter-feeders, there are no widely established control options for bighead and silver carp other than preventing introduction.

Asian carp can also be extremely hazardous to boaters and water sport enthusiasts. The silver carp, when startled by the sound of passing motor craft, can jump up to ten feet out of the water and into moving boats causing property damage and injuring boaters. Being hit by a jumping carp is like being struck with a fast-moving bowling ball, making water skiing and jet skiing very risky in areas with large numbers of silver carp.

Asian carp are a serious problem but efforts to deal with this invasive pest have been too small and largely ineffective. The Stop Asian Carp Act of 2011 was enacted to study the feasibility of the hydrological separation, such as electric barriers, of the Great Lakes and Mississippi River basins.[22] The study included researching techniques that prevented the spread of carp from flooding, wastewater and storm water infrastructure, waterway safety operations, and barge and recreational traffic. In 2012, the U.S. Senate and House introduced new bills aimed at combating the spread of Asian carp into the Great Lakes by expediting some items of the Stop Asian Carp Act of 2011.[23] The Water Resources Development Act of 2020 provided $25 million to control Asian carp in the Tennessee and Cumberland river basins. Tennessee and Cumberland river basins.