Thin ozone layer may be giving whales sunburn

18:59, Nov 11 2010

Whales basking in the sunshine while coming up for air could be getting sunburnt.

International research indicates that the depleted ozone layer is harming whales as well as humans and lighter- skinned whale species are suffering most from the effects of exposure to ultraviolet radiation.

The scientists behind the research, who spent three years studying whales in the Gulf of California, said the sunburn – evident in lesions on the whales' skin – could be a result of the ozone layer's decreased ability to block UV rays.

One of New Zealand's leading whale researchers, Auckland University scientist Rochelle Constantine, said the research could explain markings on Bryde's whales in the Hauraki Gulf.

"They are there year-round and they're lightish grey. They would be more vulnerable to these kinds of lesions." The Bryde's whales could be vulnerable to sunburn because they spend the year in New Zealand waters and under a thin ozone layer.

Dr Constantine had seen the lesions the researchers attributed to sunburn on humpback whales – also quite light in colour – in Tongan waters. Until now, researchers had been unable to explain what they had seen.

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The humpbacks spent their summer months in Antarctica, and Dr Constantine said the ozone layer there was also very thin.

"The humpbacks we're getting in our waters could be getting a double dose. In the summer it's light 24 hours a day."

Dr Constantine said scientists in New Zealand could review photographs of whales which showed markings.

Although there was nothing researchers would be able to do to protect whales from sunburn, Dr Constantine said she hoped it would make people mindful that human activities could have wide implications.

DOC marine ecologist Nadine Bott agreed.

"It highlights the impact of the ozone layer and that the way we live affects quite significant processes, and has a much wider eco-system effect."

Sperm whales could be at a high risk of sunburn because they spent a great deal of their time at the water's surface, but Mrs Bott said they were protected by their incredibly thick skin.

The study has been published in the Royal Society's biological research journal Proceedings of the Royal Society B.

The layer has been thinning because of the influence of CFCs, and while their emissions have now largely been controlled, there is debate over the extent of the ozone's recovery.

The Dominion Post