Monday, 17 January 2011

Why is the White Clawed Crayfish important to be saved?

The White Clawed Crayfish (Austropotamobius pallipes) is the only native Cray fish species present in UK. In recent years the density of White clawed crayfish have declined in huge number and it’s been officially upgraded from “vulnerable” to “endangered” on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Due to its severe population decline it is protected under Wildlife and Countryside Act 1981 (as amended) and The Conservation (Natural Habitats, &c.) Regulations 1994, which states that to kill or injure or try to sell the white clawed crayfish is a legal offence and the person is guilty to pay fine of £5000.

White clawed crayfish has special characteristics i.e. they prefer to live in fresh water with more oxygen and their existence helps us understand how healthy our rivers are. The major cause of extreme decline in White clawed crayfish population is the non native species called signal crayfish, an origin of North America. These Signal Crayfish are larger than our native species which eats of all possible nutrients, not allowing other species to survive. Moreover the killer crayfish carries a plague which does not affect to itself but is vulnerably infectious to white clawed crayfish and other aquatic living beings. Due contaminated water and plague spread by Signal Crayfish, up to 70% of White clawed crayfish has lost their existence and is expected to extinct from the world if protective measure are not taken on time.

White clawed crayfish mitigation can help in saving the species. There is several mitigation schemes which can be designed based on white clawed crayfish habitat surveys. This includes translocation of the crayfish to save them from infected water or installation of stone walls and improving vegetation, etc. The public is required to identify the white clawed crayfish, be aware to protect them and take measure like to keep fishing nets clean and dry to not let the crayfish plague spread.