Asian Carp Overview
The term “Asian carp” refers to the bighead carp (Hypophthalmichthys nobilis), black carp (Mylopharyngodon piceus), grass carp (Ctenopharyngodon idella), or silver carp (Hypophthalmichthys molitrix), originating in Asia. Earning the title of “injurious wildlife,” there is an all-out war on these fish to contain, control, and, if possible, eradicate them from U.S. waters all together. Federally regulated, it is illegal to import, export, or transport Asian carp between states without a permit.
Grass Carp were the first to be introduced into the United States in 1963 by the U.S. Fish and Wildlife Service (USFWS).¹ They were used in controlling aquatic weeds and phytoplankton in aquaculture. The move proved to be successful, and over the next decade federal agencies and universities encouraged the spawning and stocking of grass carp. It was seen as a biological triumph to discover a non-chemical solution for the weed issue in fisheries. The first accidental release of the carp into the wild occurred at a USFWS lab in Stuttgart, Arkansas. Only six years after that initial accident, grass carp were present in 16 states, as well as established in the Mississippi River System.
A non-reproductive version of the grass carp (referred to as a triploid grass carp) strictly monitored by the USFWS is still used for weed control today.
Grass carp can eat up to 100 percent of their body weight in plant matter a day. They can reach 59 inches in length, 99 pounds, and can live over 20 years. Grass carp only digest about half their food, excreting the other half as waste, aiding in the growth of algae blooms.
Black Carp feed on small invertebrates, snails, and mussels, can weigh up to 71 pounds, and measure up to 59 inches long. They were brought in unknowingly in shipments of imported grass carp.4 Although black carp have not “officially” been established in the U.S., they pose the greatest threat to the Great Lakes area. Sighted in the Gulf Coast, Missouri, and Illinois, officials worry that if they were to make it into the Great Lakes, the already much-threatened mollusk population would be wiped out.3
Bighead Carp, also introduced for algae control in fisheries and sewage treatment plants in the early 1970s, were found in open waters by the early 1980s.3 Preferring zooplankton (tiny aquatic animals) for food over phytoplankton (tiny aquatic plants, namely algae) dampened their success in aquaculture and increased their damaging effects in open waters. During the mid-1990s, they experienced a population boom, crowding out native fish such as the bigmouth buffalo and shad, who also feed on zooplankton. Bighead can weigh up to 100 pounds and measure up to 60 inches in length.
Silver Carp, the fastest growing of the group, can weigh up to 110 pounds and measure up to 39 inches long. Known for their ability to launch themselves up out of the water, the fish can “fly” up to 10 feet in the air when startled by boat motors.
Skiing in waters where silver carp are prevalent is dangerous, and many injuries involving broken bones have occurred. Damage has also been caused by the fish colliding with boats themselves, resulting in broken equipment. Feeding mostly on algae, silver carp compete with larval fish and mussels, who need the same food to survive.
Not to be confused with the bottom-feeding, barb-faced, common carp, Asian carp are entirely different. Although common carp are also a nuisance, they don’t hold a candle to the enormous (and enormously hungry) Asian carp that are wiping out plants and zooplankton, wreaking havoc on the food chain and thus entire ecosystems.
Graphic Courtesy AsianCarp.org