Water quality boost for Burry Estuary
Water quality in the Burry Estuary is probably better than any time in living memory making it more attractive to aquatic and bird life, claim scientific experts.
The irony is that misinformed protestors have been blaming water quality for cockle deaths when in fact it is parasites that specifically target cockles only that have been responsible.
Scientists have been investigating the death of thousands of tonnes of cockles in the Burry Inlet since 2002 in an exercise that has cost more than £12million.
They have found two parasites alien to the British coast are the likely cause.
They are certain the cockle mortality has no link with water quality.
The scientists are now focusing attention on the parasites which may be causing the shellfish to die prematurely.
A final report into the deaths, which have hit the cockle industry off Gower and Llanelli, is expected in April.
Giving evidence to Carmarthenshire County Council, Environment Agency Wales, Welsh Water and the Countryside Council for Wales (CCW) said the focus was now on possible biological factors.
Stuart Thomas, of the Environment Agency, said since 2002, up to 95per cent of the estuary's cockles were dying after about a year where normally they would be expected to live three,four or more years years.
The two parasites, in a difficult to explain enabling process, reduced the expected life span of cockles from four or five years to just one.
This meant the young cockle spat after being invaded by the parasites reached their reproductive cycle in months and died within a year.
There were no fewer cockles in the estuary but a lot fewer reaching maturity or that of marketable size for the cockle industry.
He said: “There are plenty of cockles there but they are not seeing through their life cycle to their second, third or fourth years”
Mr Thomas insisted: "The quality of the water and the water at the shellfish beds is improving."
He said scientists from a number of universities and research centres had also looked at other factors such as water temperature.
"One very interesting development was the discovery of a brand new parasite never seen in UK waters," he added.
These were the Minchinia tapetis and Minchinia mercenaria usually found in American clams.
They have been found on other parts of the British coast experiencing similar cockle deaths especially at The Wash.
Huw Williams of CCW said the problem was not affecting any other type of shellfish. But Oystercatchers, whose principal food source was cockles, were also in decline.
"It's something unique to the cockles themselves that is causing them to die in their first year," he added.
"There are plenty of cockles there but they are not seeing through their life cycle to their second, third or fourth years."
Mr Williams said as well as affecting cockle gatherers, the problem was hitting some of the estuary's bird population - in particular, oystercatchers.
He said while roosting numbers of oystercatchers were about 80per cent of what would normally be expected. Many were flying away to find food as the large cockles they normally relied on were scarce.
"The oystercatchers in the Burry Inlet were not putting on the fat they would expect over the winter."
Welsh Water said it had invested £69m in sewerage capacity, storage and treatment to improve water quality in the area.
All new building developments are assessed for their potential impact and, under a voluntary deal, Carmarthenshire and Swansea councils have agreed a limit of 1,000 new homes each in the area until further work is done.
Mr Thomas said the Environment Agency had taken on the role of managing the cockle beds, and when the report is published it may recommend changes to the licensing of gatherers.
"We agree there's a lot more work that needs to be done," he added.
"We will be expecting recommendations to come out of the report when it is published."
Carmarthenshire council chief executive Mark James said after the meeting: “It was good to hear from experts their field emphatically time and again that the water quality in the estuary is good and improving.
“The scientific evidence in relation to cockle mortality was provided to the environment scrutiny committee and it was explained that all studies have concluded that there is absolutely no link between water quality and cockle mortality.
“Members of the committee heard that the cockle deaths were happening all over the UK and elsewhere in Europe. They also heard that a new parasite may have a part to play in explaining the situation. Members also heard how there had been a bumper crop of young cockles in 2010.
“It was encouraging for members to hear there had been significant investment over the past 10 years into the sewage system improving water quality by more than 80per cent.
“Planned developments to Llanelli will further improve the situation as more surface water is removed from the combined sewer system.
“The town centre Eastgate and the Stradey Park developments in particular will remove considerable amounts of surface water therefore reducing potential spills at times of heavy rainfall.”
The irony is that misinformed protestors have been blaming water quality for cockle deaths when in fact it is parasites that specifically target cockles only that have been responsible.
Scientists have been investigating the death of thousands of tonnes of cockles in the Burry Inlet since 2002 in an exercise that has cost more than £12million.
They have found two parasites alien to the British coast are the likely cause.
They are certain the cockle mortality has no link with water quality.
The scientists are now focusing attention on the parasites which may be causing the shellfish to die prematurely.
A final report into the deaths, which have hit the cockle industry off Gower and Llanelli, is expected in April.
Giving evidence to Carmarthenshire County Council, Environment Agency Wales, Welsh Water and the Countryside Council for Wales (CCW) said the focus was now on possible biological factors.
Stuart Thomas, of the Environment Agency, said since 2002, up to 95per cent of the estuary's cockles were dying after about a year where normally they would be expected to live three,four or more years years.
The two parasites, in a difficult to explain enabling process, reduced the expected life span of cockles from four or five years to just one.
This meant the young cockle spat after being invaded by the parasites reached their reproductive cycle in months and died within a year.
There were no fewer cockles in the estuary but a lot fewer reaching maturity or that of marketable size for the cockle industry.
He said: “There are plenty of cockles there but they are not seeing through their life cycle to their second, third or fourth years”
Mr Thomas insisted: "The quality of the water and the water at the shellfish beds is improving."
He said scientists from a number of universities and research centres had also looked at other factors such as water temperature.
"One very interesting development was the discovery of a brand new parasite never seen in UK waters," he added.
These were the Minchinia tapetis and Minchinia mercenaria usually found in American clams.
They have been found on other parts of the British coast experiencing similar cockle deaths especially at The Wash.
Huw Williams of CCW said the problem was not affecting any other type of shellfish. But Oystercatchers, whose principal food source was cockles, were also in decline.
"It's something unique to the cockles themselves that is causing them to die in their first year," he added.
"There are plenty of cockles there but they are not seeing through their life cycle to their second, third or fourth years."
Mr Williams said as well as affecting cockle gatherers, the problem was hitting some of the estuary's bird population - in particular, oystercatchers.
He said while roosting numbers of oystercatchers were about 80per cent of what would normally be expected. Many were flying away to find food as the large cockles they normally relied on were scarce.
"The oystercatchers in the Burry Inlet were not putting on the fat they would expect over the winter."
Welsh Water said it had invested £69m in sewerage capacity, storage and treatment to improve water quality in the area.
All new building developments are assessed for their potential impact and, under a voluntary deal, Carmarthenshire and Swansea councils have agreed a limit of 1,000 new homes each in the area until further work is done.
Mr Thomas said the Environment Agency had taken on the role of managing the cockle beds, and when the report is published it may recommend changes to the licensing of gatherers.
"We agree there's a lot more work that needs to be done," he added.
"We will be expecting recommendations to come out of the report when it is published."
Carmarthenshire council chief executive Mark James said after the meeting: “It was good to hear from experts their field emphatically time and again that the water quality in the estuary is good and improving.
“The scientific evidence in relation to cockle mortality was provided to the environment scrutiny committee and it was explained that all studies have concluded that there is absolutely no link between water quality and cockle mortality.
“Members of the committee heard that the cockle deaths were happening all over the UK and elsewhere in Europe. They also heard that a new parasite may have a part to play in explaining the situation. Members also heard how there had been a bumper crop of young cockles in 2010.
“It was encouraging for members to hear there had been significant investment over the past 10 years into the sewage system improving water quality by more than 80per cent.
“Planned developments to Llanelli will further improve the situation as more surface water is removed from the combined sewer system.
“The town centre Eastgate and the Stradey Park developments in particular will remove considerable amounts of surface water therefore reducing potential spills at times of heavy rainfall.”
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