HC Deb 14 October 1996 vol 282 c792W
Mr. William Ross

To ask the Minister of Agriculture, Fisheries and Food what estimate he has made of the number of sites in the United Kingdom in which the American Signal crayfish, Pacifartacus Leniusulus, is(a) present and (b) breeds; and what effect its presence has had on the native British white clawed crayfish. [40381]

Mr. Baldry

American signal crayfish are widespread in England, predominantly south of a line between the Wash and the Bristol Channel, and also in parts of Wales. There are no known populations of signal crayfish in Scotland or in Northern Ireland. Many populations of native British white clawed crayfish have been displaced by the larger, more aggressive signal crayfish which breed and grow more quickly. They have also been affected by the fungal disease known as crayfish plague, which can be carried by signal crayfish.