September 6, 2011
U.K.

Offshore wind farms still a suspect in “corkscrew” seal death probe

By Jessica Shankleman, Business Green, www.businessgreen.com 6 September 2011

Initial tests reveal harbour seals were killed by ship propellers, but scientists have no proof which ship propulsion systems are to blame

Experts investigating a spate of horrific seal deaths in UK waters have urged people not to jump to conclusions over the possibility that boats servicing offshore wind farms could be to blame, after initial research on the cause proved inconclusive.

Last year, at least 50 corpses of seals with a clean “corkscrew” cut running from head to tail were washed up on Britain’s east coast, prompting scientists at the Sea Mammal Research Unit at St Andrews University to start investigating the deaths.

Presenting their initial findings, researchers said they do not yet know exactly which ships are involved, but they did state that, in many cases, the suspected vessels are not associated with wind farm construction.

The study is ongoing, but early research appears to have confirmed that a ship propeller caused “corkscrew-style” mutilations on the seals’ bodies.

Acoustic tests have shown that female harbour seals can be attracted to the ship’s low-frequency humming propellers, which sound like the mating call of a breeding male.

Professor Ian Boyd, director of Scottish Oceans Institute and the Sea Mammal Research Unit, told BusinessGreen that it is not yet possible to blame or rule out offshore wind farm construction vessels.

“It would be incorrect to specifically mention ships associated with wind farm development in relation to this problem,” he said. “For example, there are no wind farm developments in some of the areas where carcasses have been washed up.”

He was unable to say when the cause of the deaths would be identified, adding that an answer may never be found.

“In reality, they are probably caused by a number of different factors all occurring simultaneously, but these factors only align very rarely,” he said.

“This makes the problem devilishly difficult to solve. The public would like to be able to point the finger at the problem, make decisions about how to solve it, and then move on. Unfortunately, it’s not that simple with these multi-factorial problems.”

When the news of the deaths first emerged, it was suggested in some reports that the building of the Sheringham Shoal offshore wind farm could be to blame. But the allegation was vigorously denied by Scira, Sheringham Shoal’s main contractor, and by harbour operator Wells Harbour Commissioners.

Advocates of the wind industry industry maintain there is little evidence to suggest wind farms are responsible for high wildlife death rates, while insiders are also quick to point out that traffic and household pets pose a far greater threat to British wildlife.

URL to article:  https://www.wind-watch.org/news/2011/09/06/offshore-wind-farms-still-a-suspect-in-corkscrew-seal-death-probe/