Alien crayfish threat

THE National Parks and Wildlife Service (NPWS) has called for extra vigilance to protect Irish crayfish from the introduction of foreign species.

The white-clawed crayfish (Austropotamobius pallipes) is unique to Ireland and could be threatened with “crayfish plague”, a fatal disease, if alien crayfish find their way into Irish waters.

Freshwater crayfish look like small lobsters. While six species can be found in Europe, only one continues to thrive in Ireland. The fatal disease was carried by crayfish from North America into Europe and now all are threatened. Many live wild in England.

Ireland is fortunate in being the last European country to have no alien crayfish.

The fungus-like plaque is related to potato blight and grape disease. It is not necessary for the American species to be present, as the fungus can be transferred on wet nets, boots, boats, and even on fish for re-stocking.

Crayfish are a valuable food item for many freshwater species including otter, heron, trout and pike.

“We have good stocks of native crayfish in Ireland, but the future is under a cloud because of the risk of alien species into Ireland,” according to the NWPS.

Anglers are asked to play their part and look out for anyone who might use imported crayfish as bait. If in doubt, contact NPWS at natureconservation@environ.ie or 1800-405000.

An initiative to safeguard rare fish in a North Wales lake has recorded its first major success. Dwindling numbers of arctic char (Salvelinus alpinus), also known as Torgoch, in Llyn Padarn, Llanberis, were causing a concern for their future.

Now Environment Agency Wales (EAW) has caught a number of the fish – which can only be found in a few deep lakes in North Wales – on their way to spawn and transferred the fertilised eggs to its Mawddach hatchery.

The agency is now looking for a suitable lake to release these fish later this year to establish a reserve population. This means that if the char, a survivor from the Ice Age, disappear in Llyn Padarn, the species could be reintroduced to the lake when conditions improve.

Agency officers had been netting for spawning char in Llyn Padarn for seven days before catching eight fish, stripping them and fertilising the eggs. The adult fish were then released back into the lake.

David Edwell, EAW North Wales area manager, said: “The algal bloom last summer caused major problems by reducing oxygen levels, which is important to the char. Another algal bloom next summer could place the fish at serious risk.”

The initiative is supported by Countryside Council for Wales. For more information, contact Curig Jones on 029-20466251 or curig.jones@environment-agency .gov.uk.

The Minister of State at the Department of Communications, Energy and Natural Resources, Conor Lenihan, has made an order to restore the existing fish ladder at Fermoy Weir on the River Blackwater in Co Cork.

“In light of discussions with the European Commission and Attorney General, I have come to the conclusion that repair to the existing fish ladder is the appropriate action,” the Minister said.

Acknowledging that the issue is contentious, he said the impact of repairs on fish migration will be closely monitored and if the required improvement is not achieved, he would not hesitate to undertake further major works.

It is hoped the decision will resolve the problem. The town council has been urged to expedite the repairs and to engage actively with the fisheries board to monitor the impact.

The Irish Specimen Fish Committee has published its annual report for 2009.

Free copies are available from the Central Fisheries Board, Swords Business Campus, Swords, Co Dublin.