(Nov. 10) -- With the ozone layer thinning, whales are getting more sunburned as they come to the water's surface to breathe or fish.
That's according to a report published today by British and Mexican researchers who've been studying the effects of the sun's ultraviolet radiation on whales in the Gulf of California. Scientists studied more than 150 blue whales, sperm whales and fin whales for three years, taking photographs and small skin samples from the whales' hides -- where they found blisters from sun damage.
"They need to come to the surface to breathe air, to socialize and to feed their young -- meaning that they are frequently exposed to the full force of the sun," the study's lead researcher, Laura Martinez-Levasseur of the University of London, told the BBC.
And without fur or other sun protection from Mother Nature, whales are more vulnerable to sunburn than other animals. "Humans can put on clothes or sunglasses -- whales can't," Martinez-Levasseur also told The Associated Press.
More than half of the whales tested had "sunburn cells" in their skin, revealing DNA evidence of UV damage, Australia's ABC News reported. Even more alarming was the pace at which blue whales seemed to be suffering from sunburn, with the number of blisters on that species increasingly dramatically in just three years.
But just like humans, whales can also produce more pigment in their skin to protect them -- like the effect of tanning in humans, when your skin gets darker to protect you from sunburn.
"Whales are being exposed to the sun, and they are having acute sunburn damage. But we also found they are able to respond to that either by producing more pigment or increasing the rate of apoptosis," another of the study's researchers, Karina Acevedo-Whitehouse, a wildlife molecular epidemiologist from the Zoological Society of London, told The Christian Science Monitor. Apoptosis is a natural process in which the body removes damaged or dead cells and regenerates new ones.
Researchers also found that the darker-skinned fin whales had fewer skin lesions and evidence of sunburn than their paler-skinned relatives, blue whales. The variation is similar to racial differences in humans, whose vulnerability to the sun can depend on their skin color or race.
So far, there have been no confirmed cases of skin cancer among the whales in this study. But researchers were able to take only small samples from the whales' hides without harming them, using a crossbow-fired dart. Biopsies were then performed on those samples.
The Gulf of California is a wildlife-rich body of water that separates Baja California from the Mexican mainland. The United Nations lists it as a World Heritage site.
The study is published in the Proceedings of the Royal Society B.
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