MOAFS June 2003 Newsletter, President's Message, Page 1

The following letter was submitted on behalf of MOAFS to the Chief Division of Environmental Quality, U.S. Fish and Wildlife Service, concerning the mentioned species.

Dear Sir or Madam:

The Missouri Chapter of the American Fisheries Society (MOAFS) supports the listing of bighead and silver carp as injurious species under the Lacey Act. Declaring these fish injurious, which will ban transport of live fish across state lines, will limit the future expansion of these fishes in the United States. Missouri is experiencing first hand the negative effects of the silver and bighead carp introduction. Although it is too late for many of Missouri’s waterways, and although silver and bighead carp have shown a marked disregard for state boundaries, we feel that it is important to do what we can to limit the further expansion of these fishes to new watersheds.

Bighead carp were first found in Missouri in the Mississippi River in 1989, probably having come up the river from downstream states. They expanded their range entirely through the Missouri portions of the Mississippi River and Missouri state by 1993, reaching very high densities and biomass by the mid 90’s. Silver carp invaded the Missouri River in large numbers in 2000, and now may already be the most abundant fish in the river. Silver and bighead carp account for huge biomasses in the Missouri River, sometimes exceeding well over a ton of fish in the pool behind a single wing dike. Bighead and silver carp feed on plankton, thus competing with the juvenile life stages of almost all native species, and with the native paddlefish, which is a planktivore throughout its life. Bighead and silver carp are capable of feeding on much smaller particles than paddlefish, which puts them at a competitive advantage.

The introduction of new species that reach huge biomass and feed low on the food chain is a recurring nightmare in the United States. The zebra mussel in the Great Lakes, and the Potamcorbula clam in western estuaries are good examples. These introductions make dramatic and often deleterious changes to the trophic cascade. It is difficult to exactly quantify the negative effects of the Asian carps on native species because obtaining population estimates of organisms in large rivers is rarely possible. One thing is certain – when a system is producing tons of Asian carps, something else in the system is suffering.

Bighead and silver carp have negative impacts that extend beyond the ecosystem into economics and public safety. Commercial fishermen must contend with tons of Asian carps that fill and damage their nets, but the Asian carps have so little commercial value that they are not usually worth transporting to market. Silver carp have a propensity to leap high into the air, colliding with boats and boaters. A collision with a twenty-pound fish at twenty miles per hour could easily prove fatal, and there have already been many serious injuries. The fish also cause property damage when they leap into boats, smashing windshields, depth finders, radios, fishing rods, and other gear. These are not rare occurrences. On one day last week alone, eleven fish totaling over 150 pounds jumped into a US Geological Survey research boat. All four of the workers on the boat were struck at least once by jumping fish. One person was struck painfully in the side of the face by a twenty-pound fish that leaped over six feet in the air. Another was hit hard in the throat by a large fish that then fell back overboard, and thus was not counted in the above eleven fish. Silver carp constitute a serious danger to the boating public.

There will be arguments that these fish are already here, and thus it is too late for the listing to have a positive effect. To this we reply that there are many watersheds in which bighead and silver carp have not yet been established. Listing will help keep these watersheds safe from the invaders. Silver and bighead carp are often “contaminants” in shipments of other species. The recent capture of bighead carp in a Chicago lagoon near Lake Michigan has been attributed to a contaminated stocking of grass carp. Listing the fish will force aquaculture facilities with silver and bighead carp to take care to avoid such contamination. Also, there is a significant market for live Asian carp in Asian markets in the US and Canada. There is a very high potential for these fish sold live to be released in new watersheds. Listing under the Lacey Act would inhibit live transport to markets in areas where the fish are not yet established.

For these reasons, MOAFS strongly supports the listing of both silver and bighead carp as an injurious species under the Lacey Act. MOAFS is a scientific organization of about 200 professional aquatic resource managers, researchers, and aquaculturists from throughout Missouri.