Black Carp

Questions and Answers



Draft 4 / 7-26-02



1. What is the U.S. Fish and Wildlife Service proposing, with regard to the black carp?


The U.S. Fish and Wildlife Service is proposing that the black carp be placed on the list

of injurious species, which would prohibit the importation of live fish or their eggs into the United States, and would also prohibit interstate transportation of the fish. This is an action taken at the discretion of the Secretary of the Interior under authority of the Lacey Act, when such a listing is deemed necessary “to protect the interests of human beings, and wildlife and wildlife resources from the purposeful or accidental introduction and subsequent establishment of black carp populations into ecosystems of the United States.”



2. When will this prohibition take place?


A proposal to place a species on the injurious species list does not guarantee that the action will, in fact, happen. Following publication of this proposal in the Federal Register, there will be a 60-day period for public comment. Following that, the Service must then evaluate the public comment and determine if the process should proceed to what is called the Final Rule phase. Should the decision be to go ahead, a Final Rule would be prepared and published in the Federal Register. The prohibitions on importation and interstate transportation would take effect 30 days after the Final Rule is published.



3. What danger do black carp present?


The grass carp, a close Asian relative, expanded into all of the Lower 48 States except Montana and Vermont following its introduction into Arkansas and Alabama in 1963. If black carp were to escape or be released into the wild, they would likely survive and or become established with or without reproduction. Black carp would likely spread throughout the U.S. since there are no known limiting factors. In their native habitats, these fish feed on snails and mussels that are similar to those found in many American rivers, especially those in the Southeastern U.S. The fish would compete for food with native species of birds, fish and small vertebrates. A dramatic decline in the population of snails, which play an important role as grazers of algae, could produce sudden surges in algae mats, upsetting natural wildlife habitats. Additionally, black carp host many parasites and flukes as well as bacterial and viral diseases that could infect sport, food or threatened and endangered fish species, and the likelihood and magnitude of effect on threatened and endangered species is high. Of 300 groups of freshwater mussels nationwide, 67 percent are vulnerable to extinction or have already gone extinct, and 69 species remained federally protected. Freshwater mollusks play a critical ecological role in maintaining the health of aquatic ecosystems; they also have the potential to negatively affect the cultured pearl industry through predation on commercial mussel species.



4. How would you describe the black carp?


The black carp – also known as snail carp, Chinese black carp, black amur, Chinese roach or black Chinese roach, is a freshwater fish that inhabits lakes and lower reaches of large, fast moving rivers. The species inhabits most drainages of eastern Asia. Its natural range includes China, parts of far eastern Russia and possibly northern Vietnam. Records of black carp in Taiwan and Japan likely represent introductions. The fish typically grow to more than 3 feet in length and weigh, on average, about 33 pounds. They can reach 5 feet in length and weigh up to 150 pounds. Individuals have been known to live 15 years. Adults possess powerful crushing teeth that permit the fish to crush the shells of large mollusks. A 4-year-old black carp can consume an average of 3 to 4 pounds of mussels per day. Females spawn annually, depositing

129,000 to 1.18 million eggs a year, depending on body size. Black carp are one of four species of Asian carp; the other three – silver carp, bighead carp, and grass carp – have received media attention of late because of their presence in the Mississippi River system and the threat they pose to the Great Lakes Basin. Black carp are different from the other three in two important ways: 1) Black carp have not been found in the wild, and 2) they eat only mussels and snails.



5. If people already have these fish, will they be confiscated or destroyed?


No. The states have the right to determine if the fish remain legal within their borders. Assuming they are legal in a given state, owners will retain the right to possess the fish and to use them in any way that is legal according to their respective state laws. As stated above, importation and interstate movement will be prohibited.



6. Where are these fish in the United States? How did they get here?


Black carp are believed to be maintained in research and fish production facilities in Arkansas, Louisiana, Mississippi, Missouri, North Carolina, Oklahoma and Texas. The fish were imported from Asia and sent to a private fish farm in Arkansas in the early 1970s, arriving as a “contaminant” in imported grass carp stocks. The second importation of black carp into the United States occurred in the early 1980s, when some fish farmers found them useful as a control agent for the yellow grub, which can affect catfish, and as a food fish. The fish were also imported by a Mississippi fish farmer in the early 1980s and by a fish farm operation in Missouri between 1986 and 1988. Only a small number of the commercial catfish and striped bass farms presently use the carp as a biological control agent, and substitute control mechanisms for yellow grub are available. No clams, snails or mussels were added to the endangered and threatened species list until 1976, and there were likely fewer catfish farmers then than today. When black carp were initially approved for entry into the United States more than 25 years ago, no threat was perceived. Today, 102 clams, mussels and snails are listed as endangered or threatened, making black carp a legitimate threat.



7. Where are black carp being used?


We believe black carp are being used in Arkansas, Mississippi, Texas, Missouri, Louisiana and possibly North Carolina. The U.S. Fish and Wildlife Service expects to receive more data on the use and value of black carp during the public comment period, which remains open until September 30, 2002. It is to the enormous credit of fish farm operators that no black carp have been released into the wild. However, even the most responsible operator may be hard pressed to prevent escape in the wake of a catastrophic natural disaster, and that’s one of the major reasons for this listing proposal.



8. Will this prohibition affect fish farms where the black carp are being used?


As long as the fish farms are not importing black carp or moving them across state lines, there should be no adverse effects on their operation. However, given the potential negative impacts of the species, we hope all users of black carp will find an acceptable alternative to controlling the snails.



9. So why not eradicate these fish?


At the moment, none have been found in open waters, and none are known to be established in the wild. Decisions about eradication usually rest with the State fish and game agencies, not with the U.S. Fish and Wildlife Service.



10. If none are in the wild, why should we be concerned?


The likelihood of escape or release of black carp is high. Aquaculture farms that use the black carp are located in the Southeastern U.S., and much of the Mississippi River delta is at moderate to high risk of natural disasters, including tornados, flooding and hurricanes. A natural disaster in the Southeast could result in a release of black carp from aquaculture farms (the first and only known introduction of black carp into a natural waterway occurred during a flood; in that instance, the fish were believed sterile and did not establish a population). Should the black carp become a popular food fish, they would be farmed on a large scale and risks of escape would increase correspondingly.



11. Why is the U.S. Fish and Wildlife Service proposing to list sterile black carp as well as reproductively viable black carp? Wouldn’t sterile black carp present less of a threat?


The risks of accidental release of black carp are high due to the locations of the facilities using them. Once escaped into open waters, eradication is virtually impossible. Even sterile populations are likely to have significant impact on natural systems. Black carp will feed on mollusks regardless of their reproductive ability; they are capable of eating 3 to 4 pounds of mollusks a day and can live up to 15 years. Additionally, the methods used to produce sterile fish do not guarantee 100 percent sterility, meaning that a small percentage of fertile fish may be found among groups of sterile fish.