Sun control: Whales get skin cancer by UV radiation Ozone hole

Whales showing more sun damage

Skin Cancer by UV

Whales are showing signs

of acute sun damage,

raising fears

they're at risk

of skin cancer

The blisters are around 10cm wide

Whales are showing signs of acute sun damage

that researchers believe is due to rising levels of ultra violet radiation.

Ozone levels are not expected to recover for

another 40-50 years.

(quote Abbie Thomas ABC)

The research by British and Mexican researchers and published today in Proceedings of the Royal Society Bsuggests that continued depletion of the ozone layer could put whales at risk of developing skin cancers.

Researchers from the University of London , the Instituto Politecnico Nacional , and the Universidad Autonoma de Queretaro photographed and took skin biopsies from over 150 fin, blue and sperm whales in the World Heritage listed Gulf of California.

Increasing UV radiation

coming into the tropics

The ocean-going life of a whale is one of almost constant sun exposure. Although they dive for some food, much of their socialising, feeding and breeding time is spent very near the surface, where the clear water provides little protection from burning UV radiation.

Over millions of years whales have evolved skin repair mechanisms to cope with sunburn, but the new research suggests that increasing UV radiation coming into the tropics where the whales live could be overwhelming their natural defences.

Rapidly increasing blisters and lesions

Sun-induced skin blisters in Blue Whales

The researchers say the photos and skin biopsies show "widespread evidence of epidermal damage commonly associated with acute and severe sunburn".

Over half the whales tested had 'sunburn cells' in their skin - these are cells which form when the DNA is damaged by UV radiation.

Most alarmingly, when the researchers tracked the formation of sun-induced skin blisters in Blue Whales over time, they found the number of blisters had increased significantly in just three years.

With UV radiation expected to increase 4%

in the tropics and up to 20%

in the poles over the next few decades

They suggest that rising UV levels as a result of ozone depletion are to blame for the observed skin damage, in the same way that human skin cancer rates have been on the increase in recent decades. The Cancer Council of Australia says the rate of skin cancer in women rose 6.8% in the decade between 1993-2003 and for men, it rose 18.7%.

With UV radiation expected to increase 4% in the tropics and up to 20% in the poles over the next few decades, the researchers say the thinning ozone layer poses a 'significant and rising threat' to cetaceans.

Since 1970 Ozone layer levels shrunk up to 70%ozone levels are not expected to recover for another 40-50 years.

Since the hole in the Antarctic ozone layer was discovered in the 1970s, ozone levels have shrunk by up to 70% in the worst seasons. Although the CFCs which damaged the ozone layer were banned in 1987, ozone levels are not expected to recover for another 40-50 years.

Dolphins and are pygmy blue whales skin cancer

Dr Gales said blisters have also been seen in dolphins and are particularly common in the pygmy blue whales found off the coast of southern Victoria and Rottnest Island in West Australia. The blisters are around 10cm wide, and occur across the back and sides of the whales where the skin is most exposed to the sun.

source ABC Australia: abc.net.au/science