Whales tan or use other defenses to protect themselves against sunburn and skin cancer. A study published last week in Scientific Reports looked at the different ways the beloved sea mammals avoid getting a bad burn.
As humans, we already know that the combination of water and sun can do a real number on your skin. But most of us probably haven’t considered that whales face the same issues — and without access to waterproof SPF 50 sunscreen.
An international team of researchers took skin biopsies from three different whale species — fin, sperm, and blue whales. Blues were the lightest species. Fins were the darkest-skinned. Sperm whales fell somewhere in the middle.
All of the whales in the study were biopsied in the Gulf of California, offshore Mexico.
Damage to the earth’s ozone layer means that whales as well as people are subjected to higher levels of UV exposure than they would have been in the past. That’s why the team wanted to see whether or not whales were hurt by overexposure to sunlight and if they had a way to protect their skin.
The findings turned out to be what you’d expect based on our human experience.
First off, yes, whales can suffer from aging and skin lesions caused by too much sunlight. And their bodies will react to do something about it.
The light-skinned blue whales are a migratory species that don’t spend all their time offshore sunny Mexico. However, the team discovered that this species would develop tanned skin while in the Gulf of California.
By contrast, the fin whales didn’t need to tan because they were already dark. That species suffered the least amount of damage to the mitochondrial DNA in their skin even as they aged.
The intermediate sperm whales had special proteins in their skin to fight sun damage. National Geographic compared those proteins to the way humans produce antioxidants to fight cell damage.
Despite the whales’ proven responses to UV light, the team is still concerned about the effects of a vanishing ozone layer.
Mark Birch-Machin, a UK professor of molecular dermatology who worked on the study, told NatGeo he had this question: “At what point does that [skin lesion] develop into skin cancer?”
[sperm whale top photo by Kjersti Joergensen via Shutterstock]