Winds linked to whale stranding

Australian scientists predicted four months ago that climate patterns could trigger mass strandings of marine mammals around the Southern Ocean.

Two such strandings occurred last week in Tasmania and New Zealand.

In Tasmania, more than 115 pilot whales and bottle-nosed dolphins died over two days in two strandings on different sides of the island.

In New Zealand, 55 pilot whales died on isolated Opoutere Beach on Coromandel Peninsula.

University of Tasmania scientists predicted in July that strandings were more likely as the predominant westerlies over the Southern Ocean increased in strength every 10 years - known as zonal westerly winds.

A zoologist, Mark Hindell, said the winds brought colder, more nutrient-rich waters. More fish came to waters around Tasmania, drawing other deep-ocean dwellers such as pilot whales closer to shore in search of prey.

Professor Hindell and his colleague, Dr Karen Evans, uncovered the link between the weather patterns and increased numbers of whales in the waters around Tasmania while researching 300 strandings in the region over the past 80 years.

"We found a noticeable peak linked to the winds, which are a well-known climatic feature," Professor Hindell told the Australian newspaper.

"Probably we are at the peak now. I'd expect that these kinds of events could occur for the next year or so."

In July, Professor Hindell told New Scientist magazine that analysis of data collected over more than 80 years revealed that a disproportionate number of whales and dolphins beached themselves every 10 to 12 years.

"Strandings were thought to be pretty random - or suspected of being linked to climate events like El Nino - but nothing had been demonstrated. We have shown a clear pattern."

Although this does not explain precisely what causes the whales to strand, knowing about these regular peaks in beachings could help whale rescue groups prepare, by stepping up community training or patrolling beaches during danger periods.

- NZPA