ASIAN CARP

 

 

           

Five species of Asian carp now occur in the United States.  The species most anglers are familiar with is the common carp Cyprinus carpio.  Common carp, brought to the United States in 1831, were soon propagated and distributed throughout the country.  Common carp are so universally common today that they are generally considered part of the native fish community.  However, few anglers would argue that our lakes and rivers would be better without them.


Grass Carp

       Grass carp Ctenopharyngodon idella or white amur were imported from eastern Asia in 1963 to control submersed aquatic vegetation in aquaculture ponds.  Escapement from these aquaculture facilities occurred soon after importation and grass carp in the wild were first documented in the Mississippi River along Illinois in 1971.  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.  Grass carp began to appear in the catches of Arkansas’ commercial fisheries in the early 1970's, and by 1976, 25 tons were reported taken statewide.  Stocking of grass carp for control of aquatic vegetation was legalized in Oklahoma in the early 1980's.  Currently grass carp are available for purchase for private use through a number of commercial fish producers in the state.  The Oklahoma Department of Wildlife Conservation (ODWC) currently uses grass carp on its four fish hatcheries for control of aquatic vegetation in culture ponds.  Grass carp orient to flow and will quickly leave ponds when water is flowing over the spillway.  Today grass carp can be found in most reservoirs in Oklahoma and reproduction of grass carp has been verified in Lake Texoma by ODWC biologists.  Negative impacts on native organisms have been summarized to include: competition for food with invertebrates (i.e., crayfish) and other fishes; significant changes in the composition of aquatic vegetation, phytoplankton, and invertebrate communities; interference with the reproduction of other fishes; modification or elimination of preferred fish habitats; enrichment and eutrophication of lakes; disruption of food webs and trophic structure; and introduction of nonnative parasites and diseases.
   
   
     

        The importation and possession of the next three species of Asian carp are illegal in Oklahoma without the written consent of the ODWC Director.  Approval has been given for research purposes only. 








Bighead Carp from Kiamichi River

Bighead carp Hypophthalmichthys nobilis, native to the large rivers of eastern China, were first brought to the U.S. in 1972 by a private fish farmer in Arkansas to improve water quality and increase fish production in culture ponds.  Bighead carp first began to appear in open public waters in the early 1980's, likely the result of escapement from culture facilities.  The species has now been recorded from within, or along the borders of, at least 18 states and are actively reproducing up and down the Mississippi River.  Bighead carp have been reported from the Neosho River above Grand Lake and the Grand River below Grand Lake.  The presence of bighead carp in Lake Hudson has been verified by ODWC biologists.  Bighead carp have also been found in the Kiamichi River below Hugo Reservoir which makes it a certainty that they exist in the Red River. 

 
   

Commercial Fisherman with Asian Carp from off Mississippi River

  

Bighead carp have been reported to be “piling up” in large numbers below dams on many Midwestern rivers, and filling the nets of commercial fishermen to the point that nets can not be lifted and sites have to be abandoned.  The bighead carp is a very large deep-bodied, somewhat laterally compressed (narrow) fish with a very large head.  Scales are very tiny, resembling those of trout, and the eyes are situated below the midline of the body.  Gill rakers are long, comblike and close-set allowing the species to strain plankton from the water for food.  The bighead carp utilizes open water areas, moving about in the surface zones of large lowland rivers, consuming large quantities of bluegreen algae, zooplankton, and aquatic insect larvae and adults.  Because of its feeding habits, bighead carp is a direct competitor with paddlefish, bigmouth buffalo, and gizzard shad; as well as with all larval and juvenile fishes and native mussels.  Bighead carp have the unusual habit of jumping out of the water from the sound of outboard motors.  The problem has become so severe on the Missouri River that water skiers have quit using the river.
 
   
 

    The silver carp Hypophthalmichthys molitrix is also native to the large rivers of eastern China and looks and acts very similar to the bighead carp.  Bighead carp have a keel on the belly that extends only partway to the head and has dark blotches along the back.  The keel on silver carp extends all the way to the head.  Silver carp have a smaller head and mouth than the bighead carp.  Like bighead carp, silver carp were imported into Arkansas in 1973 for use as phytoplankton control in culture ponds and as a potential food fish.  Silver carp are efficient at straining suspended material from the water through use of gill rakers that are fused into sponge-like porous plates.  Silver carp are also a competitor with all larval and juvenile fishes as well as adult paddlefish, bigmouth buffalo, and gizzard shad.  Silver carp have spread throughout the large rivers in the Mississippi basin and are reproducing in off-channel and backwater habitats.  Silver carp have been found in both the Arkansas and Red rivers in Oklahoma.  Small silver carp and bighead carp resemble gizzard shad.  Cast-netting for bait in tailwaters below some major reservoirs in Oklahoma has the potential to introduce Asian carp into some of the premier sportfishing lakes in the state.  Anglers routinely cast net for bait below the Texoma Dam and use the bait to fish for striped bass or catfish in Lake Texoma.  Asian carp can be accidentally introduced into the lake through this practice.  Bighead and silver carp have reproductive requirements similar to those of striped bass.  There is a real potential to establish a reproducing population of Asian carp in Lake Texoma which could be devastating to striped bass fishery and paddlefish recovery efforts.
 
 
 
   
Black carp Mylopharyngodon piceus is native to most Pacific drainages of eastern Asia.  It was first brought to the U.S. in the early 1970's as a “contaminant” in imported grass carp stocks delivered to a fish farm in Arkansas.  A second importation occurred in the early 1980's; this time for use as a food fish and as a biological control agent to combat the spread of a trematode parasite in cultured catfish.  The first and only known escapement or release to the will occurred in Missouri in 1994 when 30 or more black carp, along with several thousand bighead carp escaped into the Osage River in Missouri when high water flooded holding ponds at a private auaculture facility near Lake of the Ozarks.  To date, black carp are the only one of the Asian carp species that has not established itself in the wild.  The species closely resembles the grass carp in appearance.  One way to tell a black carp from a grass carp is the lips.  If you have the mouth completely closed, you cannot see the upper lip from the dorsal view (a view from the top, looking at the back of the fish) in black carp, and you can see the upper lip in grass carp.  An illustration of this characteristic can be found at Comparison of Black Carp and Grass Carp The anatomy of the pharyngeal teeth is the main characteristic used to distinguish the two species. The pharyngeal teeth of grass carp are elongate with grooves or serrations, whereas those of black carp are large, molariform (looking almost like human molars) and relatively smooth.  The black carp uses these pharyngeal teeth for crushing the shells of mollusks and crustaceans, its primary food source.  Even at relatively small sizes (age 4), black carp will eat 3-4 lbs. of molluscs daily, posing a direct threat to one of the most diverse mollusk faunas in the world.  The risks that black carp pose to ecosystem integrity does not stop at its direct effect on the mollusks.  Mollusks serve a critical role in maintaining ecosystem health through their role as filter feeders.  Mollusks also serve as “early warning systems” in identifying degrading water quality.  Black carp pose a threat to other aquatic organisms through competition for food with native molluscivores and serve as hosts to a wide array of parasites that could have negative impacts on native species and potentially humans.
 
 

         

 

What can you do to help stop the spread of Asian carp? 

 

Become more informed about the spread of non-native species nationwide.  Consult your local, state, and federal conservation authorities as to the threat of non-native species and to the laws and regulations governing the importation, culture, maintenance, and stocking of non-native species.  Utilize care in the purchase and use of baitfish in lakes and streams.  Ask your bait dealers where their baitfish came from, and never release any unused baitfish to the wild; always destroy them or return them to your bait dealer.  Learn and understand the biology and needs of aquarium fish species before purchasing them for your home aquarium.  Never release pet fish or aquatic organisms from the home aquarium to open waters.  Either destroy them, sell or give them to someone else, or return them to the store where purchased for proper disposal.  Support stronger local, state, and federal regulations designed to prevent the spread of non-native species, and let others know of your concerns for the protection of native species.  Support your state and federal natural resource agencies in all of their efforts to stop the spread of non-native species.