14 DAY TRIAL // When spending too much time in the sun, without any protection, people get sunburns, and according to scientists, this does not happen to humans only.
Whales seem to be affected by the sun rays just as much as humans are, and the skin damage caused by the ultraviolet radiations is as severe as acute sunburns in people.
The problem is that the phenomenon seems to get worse over time, so several scientists from the Zoological Society of London (ZSL), Queen Mary, University of London and CICIMAR, started studying blue whales, fin whales and sperm whales in the Gulf of California, hoping to better understand the effect that the rising levels of UVR have on their health.
A number of years have passed already since the scientists have noticed blisters on the skin of whales, for the first time, but now, thanks to high-quality images, a better analysis is possible.
Researchers counted the blisters and analyzed the damaged areas by taking skin samples, and concluded that there are mainly three types of whales that show signs of skin damage, comparable to severe human sunburns.
In the Gulf of California, the UV index is situated somewhere between high and extremely high, throughout the year, and as “whales need to come to the surface to breathe air, to socialize and to feed their young, [...] they are frequently exposed to the full force of the sun,” explained lead author, Laura Martinez–Levasseur from ZSL and Queen Mary.
“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 UVR as a result of either ozone depletion, or a change in the level of cloud cover.”
Co-author Professor Edel O'Toole, from Queen Mary, said that “as we would expect to see in humans, the whale species that spent more 'time in the sun' suffered greater sun damage.
“We predict that whales will experience more severe sun damage if ultraviolet radiation continues to increase.”
And just like in humans, the sun damage was higher in whales with a lighter skin like the paler-skinned blue whales, compared to the darker-skinned fin whales.
Also, in blue wales, the symptoms seemed to get worse over the past three years during which the study took place.
“We have shown that exposure to strong sun is damaging to whales' skin,” said lead author Dr Karina Acevedo-Whitehouse, from ZSL.
“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.”
So the next step will be the analysis of the expression of genes that are involved in the production of skin pigmentation and DNA damage repair, in order to better understand the consequences of sunburns in whales.
This research was published this week in Proceedings of the Royal Society B.