Writing in the journal Scientific Reports, researchers at Newcastle University report not only do some species of whales get darker with sun exposure, incurring DNA damage in their skin just like humans, but that they also accumulate damage to the cells in the skin as they get older.
The Newcastle researchers began the study after hearing from marine biologists in Mexico who noticed an increasing number of whales in the area had blistered skin, a university release reported Friday.
They analyzed skin samples collected from three types of whale -- blue, sperm and fin.
"Whales can be thought of as the UV [ultraviolet] barometers of the sea," Mark Birch-Machin, a professor of molecular dermatology, said. "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."
Blue whales in particular have a very pale pigmentation that can darken during migrations south to warmer waters, the researchers said, along with mitochondrial DNA damage.
This internal damage to the mitochondria within cells is caused by UV exposure and is what is found in sunburned human skin, they said.
"We need to investigate further what is happening," Birch-Machin said. "If we are already seeing blistered skin in the whales caused by UV damage then we want to know whether this could develop into skin cancer and therefore serve as an early warning system.
"They are a reminder that changing climatic conditions are affecting every creature on the planet," he said.