Page last updated at 16:50 GMT, Wednesday, 11 June 2008 17:50 UK

Mystery bug killing cockle beds


Cockle gatherer Glyn Hyndham thinks the deaths are linked to poor water quality

A mystery bug has killed 6,000 tonnes of cockles off Gower and threatens the future of the industry in the Burry Inlet, gatherers claim.

They believe the problem is caused by pollution from a nearby sewage works.

Scientists from Swansea and Bangor Universities are working with the fishing community to discover the reason for the mortality rates.

Welsh Water said the cause was complex, involved several factors and warned against jumping to conclusions.

Dr Ruth Callaway from the Swansea University said the cockle population was so weak it was unable to cope with the changes in the environment.

She said: "It's possible that the pollution in the water is weakening the immune system of the cockles, but pollution would most likely affect several species and not just the cockles.

"It would be nothing for a healthy cockle because they would not die from a freshwater input or an increase in temperature.

"It's not a shortage of food and we've looked into the usual suspects, but there is no clear lead on what the reason could be."

Last year the gatherers used the Freedom of Information Act to try to establish from Welsh Water the extent of the problem.

I would still be cautious about saying that the pollution is the one true reason
Matt Longshaw, Centre for Environment, Fisheries and Aquaculture Science

Robert Griffiths, who has gathered cockles for ten years, said the company had recorded 560 spills last year against a government guideline of only ten.

He believes gatherers should be entitled to compensation. Cockle prices vary from 400 to 1250 per tonne and the industry locally supports 50 gatherers.

"There was a catastrophic failure of the sewage system in 2005 and since then over 20,000 tonnes of cockles have died," said Mr Griffiths.

"This industry is on its arse because it shouldn't have taken this long to sort the problem out and enough is enough."

"Major improvements"

Matt Longshaw, a scientist with the Centre for Environment, Fisheries and Aquaculture Science, who specialises in parasite studies, believes more research is needed to pinpoint the problem.

He said various parasites had been found in the dead cockles but stressed that none of these were a concern to human health.

"I'm not finding anything new in these cockles so there's not an unusual infection pattern going on and I would still be cautious about saying that the pollution is the one true reason," he said.

Welsh Water said in the last decade it had invested around 50 million to deliver major improvements to both the sewerage network and the sewage treatment facilities bordering the Burry Inlet.

It said last year the wastewater treatment works at Llanelli spilled 111 times.

"A scheme to reduce the number of spills at Llanelli works and Northumberland Avenue pumping station has not yet been implemented but we are working closely with Environment Agency Wales," a spokesperson said.

"We are also working with a stakeholder group, headed by Bangor University, who are investigating cockle mortalities in the Loughor estuary and three rivers.

"They advise that the cause of the mortalities is complex, involving several factors and warn against jumping to conclusions.

"There have been claims that sewage discharges in wet weather are to blame, but the loss of a reported 1500 tonnes of cockles at Pwll over the May Day bank holiday occurred when there had been no such discharges from Llanelli wastewater treatment works or Burry Port, Pwll and Northumberland pumping stations."

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