Whales Tan Like Humans: Sunshine Impacts Pigmentation

Humans aren't the only ones that get a tan. It turns out that whales can also catch a few rays from the sun. Scientists have discovered that whales increase the pigment in their skin in response to sunshine, much like humans do.

The research on tanning whales first began in Mexico. There, marine biologists noticed an increasing number of whales in the area with blistered skin. That's why researchers decided to investigate the phenomenon further, trying to find out why whales showed these changes after their annual migrations to sunnier climes.

The researchers took samples from the backs of three different species of whales to find out a bit more. More specifically, they focused on blue whales, sperm whales and fin whales. All three of these mammals migrate yearly to the Gulf of California along the northwest edge of Mexico.

"Whales can be thought of as the UV barometers of the see," said March Birch-Machin, one of the researchers, in a news release. "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."

What did they find? It turns out that the pigmentation of blue whales increase during migration. In addition, the mitochondrial DNA damage also increases, which is a sure sign of UV exposure. The same damage can be found in sunburned human skin. Sperm whales, in contrast, had a different mechanism when it came to protecting themselves.

"We saw for the first time evidence of genotoxic pathways being activated in the cells of the whales-this is similar to the damage response caused by free radicals in the human skin which is our protective mechanism against sun damage," said Amy Bowman, one of the researchers, in a news release.

In comparison to the blue whales and the sperm whales, fin whales actually received the least amount of sun damage. This isn't surprising. This species has much darker pigmentation.

The findings are important for understanding how UV radiation impacts whales. Because there's been an increase in the number of reports on blister-type skin lesions among whales, the research is crucial for better understanding how a whales' environment could be causing this damage.

The findings are published in the journal Scientific Reports.