The Weakened Ozone Layer Is Giving Whales Deep Sunburns

By Andrew Moseman | November 10, 2010 10:02 am

FinwhaleWhales don’t wear sunscreen. And because these massive sea mammals must surface to breathe, they are being exposed to more and more ultraviolet radiation sneaking through the weakened ozone layer. According to Karina Acevedo-Whitehouse, lead author of a study in the Proceedings of the Royal Society B, some whales are getting serious sunburns at an alarming rate.

From 2007 to 2009, her team sampled fin, sperm, and blue whales in the sun-drenched Gulf of California, which is the long, skinny expanse of water between mainland Mexico and Baja California.

Nearly all of the skin samples contained “sunburn cells,” abnormal cells associated with ultraviolet-induced DNA damage. These indicators were even found in the lowest layer of skin on the whales, suggesting that those individuals were suffering from very severe sunburns. [Discovery News]

Pathogens can also cause skin lesions in whales, but Acevedo-Whitehouse says the severity and the signature of sun damage suggests a large role for UV radiation. In all, the scientists studied 150 whales; 95 percent showed some sun damage and 56 showed damage down to the lowest layer.

And, just as in humans, the lighter-skinned blue whales suffered more from the sun’s rays, whereas the darkest whales, the fin whales, had the fewest abnormalities. Although darker than blue whales, sperm whales had almost the same amount of sun damage, perhaps because they spend more time at the surface breathing between dives, the researchers speculate. Also like fair-skinned humans, the blue whales seemed to respond to the sun’s rays by producing more pigmented cells, which help repair sun-damaged skin and protect it from UVR [ultraviolet radiation]. [ScienceNOW]

Based on what we know of our own anatomy, this level of sun damage to the skin would be bad news. But does whales’ increased exposure mean they are at increased risk for skin cancer, or simply that they’re tanning?

So far, there were no indications of skin cancer among the whales studied, although [coauthor Laura] Martinez-Levasseur, who is also a Ph.D. student at Queen Mary, University of London, noted that only tiny samples were taken of the massive animals. She said one of her next projects will be to examine how well whales’ cells hold up under the increased UV radiation — and whether whales’ pigmentation darkens as a result of their time spent out in the sun. [AP]

Let’s hope the whales can cope. Despite successful reductions in ozone-depleting molecules like CFCs, it could be decades before the ozone layer recovers and reaches its former strength.

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Image: Wikimedia Commons

CATEGORIZED UNDER: Environment, Living World
  • Dante The Canadian

    What are they comparing the skin samples to? Did they perform sample testing 100 years ago? 50 years ago? 20 years ago? How do we know that whales haven’t always had sunburns?

  • http://clubneko.net nick

    Thank you Dante, beat me to the punch.

    Also, we don’t know how their sunning patterns have changed over the years, they might be sunning less now that UV light is stronger, so their sunburns may be weaker than they’ve been before. Without any historical data, this is fairly difficult to know.

  • Darius2025

    Wow… biggest b*s post i’ve read in a long time.

  • scott

    Maybe the whales have always been burned, perhaps, but we are still chipping away our atmosphere all the same.

  • Karsus

    Duh

    If the whales always had sunburn problems then some evolutionary mechanism would have arisen to fix that (which is what will happen now if they don’t get extinct).

  • Kristen

    Perhaps it is something more insidious than UV rays. Perhaps it is radiation from man’s satellites and wireless communications. We have not tested the long term effects of exposure to high levels of non-ionizing radiation. The carrier waves of most cell phones produce more radiation exposure on a person in a day than most people would have been exposed to in a lifetime 40 plus years ago. It is slow, and all but impossible to prove causality because so many variables exist. However, some causal links are being found. More studies need to be done. I propose the whale’s predicament is caused by radiation exposure of a non-solar kind.

  • Brian Too

    Queue the volunteers and whale-sized containers of sunscreen! My name be Ahab and I seek the great white whale!

  • Louis

    Whales in the Gulf of California are starting to blister in the sun, say researchers who have studied them for three years.

    They blame the blisters on exposure to harmful ultraviolet radiation as the Earth’s protective stratospheric ozone layer struggles to repair itself.

    The whales get sunburned when they come up for air, rest on the surface and feed their young. “It’s the first evidence that ultraviolet light can damage their skin, but it’s difficult to say what the impact on their health might be,” says Laura Martinez-Levasseur of the Institute of Zoology in London and Queen Mary, University of London, and co-leader with Karina Acevedo-Whitehouse of the team that observed the whales between 2007 and 2009.

    Over that period, she and her colleagues studied blue whales, sperm whales and fin whales. They monitored the prevalence of blisters by taking 156 high-resolution photographs of skin on individual whales. They also took skin biopsies from 142 whales so they could analyse them for melanocytes, skin cells that react to sunlight by producing the protective chemical, melanin.

    Over the three years the proportion of blue whales with blisters rose from 10 to 60 per cent. As you might expect the melanocyte counts also varied according to lifestyle and natural differences between the species.

    Fin whales, which have very dark pigmentation and which are resident year round in the sun-soaked Gulf of California, had counts twice those of blue whales, which only visit in the summer to calve and raise their young.

    Martinez-Levasseur and her colleagues found that the blue whales suffered their worst blistering early on in the season. “When they arrive in the gulf from much colder areas, they are suddenly exposed to all this ultraviolet,” she says. But they had fewer blisters by the end of the season, so like humans acquiring tans, they do adapt to the extra radiation.

    Sun-worshipping sperm whales

    The sperm whales also suffered quite severe blistering compared with the fins, but mainly because they spend much longer than the other two species resting at the surface. “They can spend all day on the surface,” says Martinez-Levasseur, who found that the sperm whales had intermediate melanocyte counts.

    Although the researchers conclude that the increased blistering is probably down to increasing UV exposure through depletion of protective ozone, meteorologists contacted by New Scientist were more doubtful. “I’d be cautious with the link to ozone depletion,” says Guus Velders of the Netherlands Environmental Assessment Agency in Bilthoven.

    “Since about 2000, the levels of ozone have been about constant,” he says. “So I don’t think the link between UV and sun damage found in whales can be associated, as proposed, with depletion of the ozone layer.”

    But John Turner of the British Antarctic Survey says that the ozone layer won’t be fully healed till 2060 at the earliest. “So we’re still bumping along the bottom, and we’re still getting huge increases in UVB, even when there’s cloud cover,” he says.

    The researchers found no evidence of worse effects of UV exposure, such as cancers and melanomas. But as a follow-up, Martinez-Levasseur and her colleagues are monitoring the whales for increases in the activity of genes involved in repairing UV damage to DNA.

    Journal reference: Proceedings of the Royal Society B, DOI: 10.1098/rspb.2010.1903

  • Louis

    If you read the article and check the photos, the famous “bite marks” she mentions are probably remora marks, not predator marks. I can’t believe this article was published, I read it and there is no way to test if some of the histological damage is really related to the UV burns. I didn’t see any sperm whale or fin whale photos of the blisters. My question is: if these animals leave in the sea I don’t think they would develop blisters (by definition). Three years is not a good sample size either. How can they prove they actually took the biopsy samples from the blisters, it must be almost impossible. And in my opinion the microvesicles could even be parasite eggs. As far as I am concerned I don’t trust this article at all. All the information is very vague and most of it probably things they can’t even prove. I hate sexy science! It brings all of this ridiculous articles that the media just loves.

  • Louis

    Sorry, “live”!!

  • Louis

    This is an additional comment, just to think twice. Assuming that the hypothesis in this article is true, the animals in captivity (e.g. dolphins and belugas) should be exposed to even higher UV damage and should show more damage through the years. In the case of whales they spent only a few minutes in surface, and after that they dive to deep water (around 100 meters), but cetaceans in captivity are more exposed to UV damage because they can only dive a few meters. Why aren’t they showing more damage?? It is obvious the skin lesions in whales can be related to many things: predators, parasites, remoras, etc.!!!

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