Scientists from ZSL, Queen
Mary, University of London and CICIMAR, studied blue whales, fin whales and
sperm whales in the Gulf of California to determine the effect of rising
levels of ultraviolet radiation (UVR) on their health.
For a number of years
scientists have observed blisters on the skin of whales. Now, using
high-quality photos to give accurate counts of the blisters and analysing
areas of damage in skin samples, this research has found that the three
species of whale exhibit skin damage that is commonly associated with acute
sunburn in humans.
Notably, the scientists also
found that signs of sun damage were more severe in the paler-skinned blue
whales, compared with the darker-skinned fin whales, and that in blue whales
the symptoms of sunburn seem to be getting worse during the three years the
study took place.
The UV index for the Gulf of
California fluctuates between high and extremely high throughout the year.
Lead author, Laura Martinez–Levasseur from ZSL and Queen Mary, says,
"Whales need to come to the surface to breathe air, to socialise and to
feed their young, meaning that they are frequently exposed to the full force
of the sun.
"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, says, “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.”
The next phase of the research
will look at the expression of genes involved in the production of skin
pigmentation and DNA damage repair and try to gain a greater understanding of
the consequences of sun damage in whales.
Lead author Dr Karina
Acevedo-Whitehouse, from ZSL says, “We have shown that exposure to strong
sun is damaging to whales’ skin. 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.”
