Sunday, 27 March 2011

Survey and Mitigation for White Clawed Crayfish

Native of Britain White clawed crayfish is widely strewn in South and West Europe and has reached to northern Spain. Fast flowing streams are their typical habitats. They also find shelter in tree roots. These fishes are olive brown in color with pale-pink front claws that are used for collecting food and during breeding. They are of around 15 cm in size according to Ecological consultants these species play an important role in understanding ecological status of various water bodies. They are found almost throughout the year but can be found in abundance during autumn and summer because these are the times when water temperature is high. It is from during the late September that the female crayfish carries eggs and this continues till May.

But the recent studies say that white clawed crayfish are declining drastically and due to this these species are being protected under Wildlife and Countryside Act 1981. According to law selling, killing or advertising this fish would be considered as a legal offence and if found guilty the person would have to pay £5000 as fine. Moving further the studies also say that persistency of American signal crayfish has also been one of the main reasons of it getting declined because these species were extensively aggressive and carried plague that had adverse effects on aquatic living beings. This plague spread by the non-native species contaminated the water which resulted in around 95% loss of crayfish. Various programs are being encouraged for conserving white clawed crayfish.

Survey and mitigation for White clawed crayfish are carried by licensed ecology consultancies between mid of July to End of September because during this period the flow of river is low. Ecological consultants conduct survey during night by using torch. Mitigation is done by relocating the fishes if needed and by creating proper fencing.