Access digital copies of guides and regulations publications from the Nebraska Game and Parks Commission.
Issue link: http://digital.outdoornebraska.gov/i/720963
79 IMPACTS The Red Swamp Crayfish is the foundation of a major industry in the South (e.g. Louisiana) where they are harvested from the wild or cultured in ponds for sale as food or bait. Because of its popularity in the food trade, it has been widely introduced outside of its native range in North America and other countries. In Europe, it is now found in Spain, Portugal, France, England, Germany, Switzerland, Cyprus, Italy and the Netherlands. 142 The consequences of these introductions are usually negative. 111 Their introduction into European waters has resulted in numerous studies of their impacts. 113 The Red Swamp Crayfish is a carrier of the crayfish plague fungus that has been decimating the native crayfishes of Europe. Their burrowing has damaged earthen canals, levees, dams and irrigation water control structures. It is also noted that importation for aquaculture in earthen ponds is the same as transplanting them into new streams and lakes as it is impossible to keep them contained. 111 There has been one positive impact as a result of their introduction into Africa (which has no native crayfishes). Here, the Red Swamp Crayfish are eating the snails that host the Schistosomaisis parasite. But this has to be balanced against the negative effects. They have been found to eat fish eggs; they compete with native food fishes for the same foods; they damage fishing nets; they destroy beds of aquatic vegetation; and they burrow into irrigation dams. 113 In Portugal, the Red Swamp Crayfish has caused the decline (six species) or extinction (seven species) of amphibians in a 554 ha marsh. 40 In California, they reduced the abundance of invertebrates in two streams by direct predation or, indirectly, by competing for food. 133 DISTRIBUTION AND ABUNDANCE The native range of the Red Swamp crayfish is the Gulf Coast from northeastern Mexico to Florida then northward up the Mississippi to the southern tip of Illinois. It has been widely introduced outside of its native range. These are not native to Nebraska but were found in a bait dealer's tank in the summer of 2014. The dealer was located on the Missouri River downstream of Gavins Point Dam and it was reported that some had been released into the Missouri River. As of 2016, they have been confirmed as being present in the Missouri River and Lake Yankton, downstream of Gavins Point Dam.