November 10, 2010

Sunburn-Like Symptoms Observed In Whales

Like humans, whales can receive sunburn-like effects from overexposure to ultraviolet radiation (UVR), according to a new study printed in this week's edition of Proceedings of the Royal Society B.

Researchers, including Laura Martinez-Levasseur of the Zoological Society of London (ZSL), made the discovery after studying blue whales, fin whales, and sperm whales in the Gulf of California. They also analyzed high-resolution photographs of blisters and damaged areas in skin samples.

They found that three species of whale showed signs of the same type of skin damage that humans typically receive from acute sunburn; that paler-skinned blue whales were the most susceptible to the condition; and that the symptoms seemed to worsen over the three-year period during which the study took place.

"This is the first evidence that the Sun's rays can cause skin lesions in whales," Martinez-Levasseur told BBC News Science and Nature Reporter Victoria Gill on Wednesday. "The increase in skin damage seen in blue whales is a matter of concern, but at this stage it is not clear what is causing this increase. A likely candidate is rising ultraviolet radiation as a result of either ozone depletion, or a change in the level of cloud cover."

"As we would expect to see in humans, the whale species that spent more 'time in the sun' suffered greater sun damage," study co-author Edel O'Toole, a professor from Queen Mary, University of London, added in a statement. "We predict that whales will experience more severe sun damage if ultraviolet radiation continues to increase."

According to Gill, no sign of skin cancer was detected in any of the whales.

The researchers will now attempt to study the genes involved in the production of pigmentation in whale skin, as well as those that repair DNA damage, in order to better understand what types of consequences the whales face as a result of their expose to UV rays.

"We have shown that exposure to strong sun is damaging to whales' skin," said ZSL's Dr. Karina Acevedo-Whitehouse, the lead author of the paper. "We now need to understand the knock-on effects and whether whales are able to respond quickly to increasing radiation by enhancing their natural sun-protection mechanisms."


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