Thursday, August 25, 2011

Was pollution responsible for mass stranding of pilot whales?

The Telegraph (UK): Was pollution responsible for mass stranding of pilot whales?
Experts have now asked the UK government for £20,000 to carry out the first such major diagnostic tests on a super pod in Scotland - which could show the legacy of decades of pouring toxic chemicals into the sea.

No such link between strandings and pollution has ever been proved before - but scientists say they are now finding killer whales with toxic readings "hundreds" of times over the limit.

There are growing fears that Polychlorinated Biphenyls (PCB's) - which are now banned - are so prevalent in the marine environment that over a period of time they have entered the food chain widely.

The Department for Environment, Food and Rural Affairs is now being asked for £20,000 of the £50,000 of toxicology tests that the Scottish Agriculture College-led investigation into the recent stranding in Sutherland wants to probe.

The Cetacean Stranding Investigation Programme is continuing to investigate the cause of what is believed to have been Scotland's largest ever stranding of pilot whales, in the Kyle of Durness on July 22. Some 25 of the 70 whales are believed to have died.

Leading experts from the Sea Mammal Research Unit at St Andrews, the Centre for Environment, Fisheries and Aquaculture Science and Institute of Zoology in London will all be involved in the toxicology tests.

Samples have been taken from 16 of the dead whales.

SAC's Veterinary Investigations Officer Dr Andrew Brownlow said these samples provided an "unique" opportunity to conduct a whole range of diagnostic tests.

"Some of the pilot whales were around 50 years old - and their ages range down to those of a calf," he said.

"We want to run the tests to try and find the underlying cause of the stranding. We know these animals feed high-up in the food chain and many had lived a long time. PCBs have been around in the marine environment - perhaps more than anywhere else - for a very long time."

"They were used as coolants for things like generators and transformers. But they are highly toxic and long lasting. They can have a wide range of physiological effects none of which are good. Cetaceans are prone to them because they build up in the fat. Calves can have a particularly high level because they feed on fatty milk from their mothers.

"We want to see what levels of PCBs there were in this group. Some male killer whales have been found to have PCB levels hundreds of times higher than the suggested limit for humans. We just don't know the effect that PCBs are having on marine wildlife and this investigation will help us understand what is going ion in the seas. It could be very important - that is why we have asked for the funding. We hope to have an answer within a couple of weeks."

Dr Brownlow added that the possibility of killer whales, underwater earthquakes and naval explosive clearance in the area would also be probed.

Navy divers who helped in the rescue had been in the area carrying out explosions on undetonated devices in the days prior to the stranding. Nearby Garvie Island is a major military bombing range.

The Navy has denied that its explosions - which it has carried out for years in the area - could have caused the stranding.

But Dr Brownlow that the situation could be like "Russian roulette" - this time with the explosions going off at the wrong time when whales were in the area.

"We have asked the Navy for a timeline of its underwater explosions. I am also pretty sure that whatever brought them into the Kyle it was not food. It maybe that we never find a physical reason why they stranded but it's important that we look."

In May, around 60 pilot whales appeared in Loch Carnan, South Uist, although they left the loch after one of the mammals died. Another dead whale was later found on an island in the loch.

A post-mortem examination suggested the first had died of infection.

At the end of October last year, other pilot whales almost got stranded in Loch Carnan.

Less than a week later 33 whales, believed to be the same group, were found dead on a beach in Co Donegal in Ireland.

Pilot whales are known to prefer deep water but come inshore to feed on squid, their main food.

The investigation is the first one on a mass stranding in the UK for three years when a group of dolphins beached at Weymouth in Dorset.

Meanwhile the Hebridean Whale and Dolphin Trust and the British Divers Marine Life Rescue are urging residents from the more remote and isolated parts of Scotland, particularly islanders, to join them in a training course to learn fundamental techniques to assist in marine mammal strandings.

Morven Summers, HWDTs Volunteer Coordinator said:"Without the assistance of trained medics at the scene many more pilot whales at Durness would have surely perished.

"Recent events highlight the need for a wider network of trained individuals, particularly within island communities, where ferry timetables and weather can hamper the efforts of those travelling from the mainland."

The course fee is £90 - and includes the first yearâ s supporters fee and third party insurance while on a rescue. Those interested should call 01688 302620

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