Anglers - help to save the White Clawed Crayfish

The rare and protected white-clawed crayfish (Austropotamobius pallipes) is native to many of the rivers and becks in the Eden catchment. Specifically it is found in hard water, limestone rivers such as the Upper River Eden, the River Lyvennet, the River Leith and the Scandal Beck.

It is under threat of Crayfish plague, a wide spread and virulent disease, caused by the fungus Aphanomyces astaci. It is believed that it was introduced, and is spread, by the North American Signal Crayfish (Pacifastacus leniusculus).

The plague produces free-swimming zoospores that are specific to crayfish and can be carried in water and mud, and on damp equipment. The risk of picking up these spores is greatest when there is an outbreak of crayfish plague as the number of zoospores is high.

Much of the UK population of White Clawed Crayfish has been lost, the Eden catchment is one of their few remaining habitats but extra care must be taken to ensure that they survive.

How anglers can help

Crayfish plague is not only spread by Signal Crayfish, but also by equipment, water or fish that have been in contact with Signal Crayfish. To try and prevent the spread of this disease we ask you to carefully disinfect your fishing equipment.

1. After you have finished fishing please clean any mud from your fishing tackle and equipment while on site. This will reduce the risk of the spores being transferred elsewhere.

2. Dry the equipment thoroughly; this is an effective way of killing the spores as they only remain viable when damp.

3. Disinfect the equipment; this will again reduce the risk of any spores being transferred to new waters. A hypochlorite solution, such as domestic bleach, or an iodine based disinfectant can be used. Iodine based disinfectants are usually available from farm or dairy suppliers; please follow the manufacturers instructions carefully.

Thank you for you help and consideration; your action will not only protect the White Clawed Crayfish but also prevent the spread of other fish diseases.

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