Whales can get suntans and the large mammals are able to alter the levels of melanin in their skin, helping them to avoid DNA damage.
Like people, blue whales react to the sun’s rays by darkening their skin when ultra-violet (U.V.) radiation is at its most intense, according to the Canadian Press. To show this effect, scientists sampled skin from blue whales, sperm whales, and fin whales in the Gulf of Mexico between 2007 and 2009.
The science team found that melanin appeared to protect against damage to the blue whales’ DNA. Melanin is a natural pigment found in the skin of many creatures. The pigment functions to absorb UV light and helps to produce vitamin D.
The researchers also found that increased melanin production was associated with decreased skin lesions across all three species. They also found that blue whales’ pigmentation increased seasonally as U.V. light intensified.
The lead researcher behind the study, Mark Birch-Machin, a professor of molecular dermatology at Newcastle University, said in a press release: "Whales can be thought of as the UV barometers of the sea. It’s important that we study them as they are some of the longest living sea creatures and are sensitive to changes in their environment so they reflect the health of the ocean."
The researchers told The Canadian Press that their next step is to establish whether damage from U.V. radiation leads to skin cancer in whales.
The findings have been published in the journal Nature in a paper titled "Whales Use Distinct Strategies to Counteract Solar Ultraviolet Radiation."