New advice to end alien species

The Government said the crayfish were becoming an increasingly common sight in Scotland's waters. Environment minister Mike Russell has therefore launched a new leaflet on the threat the non-native species poses. It appeals to anglers, canoeists, boaters and anyone who visits Scotland's rivers and lochs to look out for signal crayfish and help eliminate them. Mr Russell said: "The signal crayfish is one of the most problematic invasive species introduced to these shores. "As well as competing with valuable native fish such as trout and salmon, the holes they bore into river banks for their nests can leave the land weak and lead to a greater risk of flooding."Signal crayfish are voracious predators which feed on insects, frogs and juvenile fish and their eggs, including those of Atlantic salmon. The non-native lobster-like creature was introduced to waters in England and Wales through fish farms about 20 years ago. In Scotland, signal crayfish were first recorded in the catchment of the Kirkcudbrightshire Dee in 1995. Since that date, specimens have been found in Scottish ponds, rivers and lochs as far north as Inverness-shire.He added that any angler who caught a signal crayfish was urged to contact Scottish Natural Heritage, Scottish Government or Fisheries Research Services.