Is the hole in the ozone layer causing “sunburn” to Antarctic animals?

The ozone hole over Antarctica grows and closes again every year; Having a hole isn’t ideal, but scientists know roughly when to expect it. However, their appearance persists increasingly throughout the year, which, according to a new study, could represent a danger to wildlife on the continent.

In the past, the depletion of the ozone layer (also known as the hole) over Antarctica generally peaked between September and October, a time when its inhabitants tend to be less active. This concluded long before the start of the Antarctic summer, when the protection of ice and snow melts and dormant animals emerge.

But for the past four years, the hole ended up staying until early summer and persisting until December; Last year’s ozone hole was also one of the largest on record. The problem, as the study’s authors point out, is that with ozone depletion also comes exposure to ultraviolet (UV) radiation.

“Once we get to December, in the southern hemisphere the sun will be much higher in the sky and the radiation reaching Earth will be greater,” study author Professor Sharon Robinson said in a statement. “We are seeing a UV index of 14 in Antarctica in December, down from pre-ozone hole levels of 6. A UV index of 14 is extreme, what we would experience during the summer in Sydney or San Diego.”

Because this coincides with the awakening of wildlife below, Robinson explained that this “means that animals and plants in Antarctica are exposed to more than twice as much ultraviolet radiation as they were in the 1970s.”

In humans, this increased exposure would be risky business, at least without applying a lot of sunscreen. UV rays, particularly UVB, are known to damage the skin and increase the risk of developing skin cancer.

Although the precise effects of ultraviolet radiation on Antarctic wildlife are unclear, the authors point to several ways the persistent ozone hole could affect wildlife, particularly for penguins and seals whose breeding season occurs in this moment.

“The doubling of ultraviolet radiation from mid-October to early December could be harmful, especially for young animals. Reflection of radiation from the surface of sea ice will increase the UV exposure of animals that breed on the ice. The timing of exposure is likely to be important,” the authors write.

It could also be bad news for smaller organisms, such as plankton, which might try to adapt by making their own “sunscreen” and, in doing so, consume valuable energy. “Prolonged UV radiation may not kill things, but we know that creating sun protection comes at a cost and that detracts from other things that animals and plants can do,” Robinson said.

That said, the study warns that some organisms may have natural defenses against UV damage. Macaroni and rockhopper penguins, for example, have pigments including melanin, which are thought to help protect their eyes from ultraviolet rays.

But where damage might be possible, the authors also highlight that the persistence of the ozone hole does not exist in isolation.

“The most important thing we can do to help Antarctica is to act on climate change: reduce carbon emissions as quickly as possible so we have fewer wildfires and do not put additional pressure on the recovery of the ozone layer,” Robinson concluded. , adding that this will also help animals by maintaining “as much sea ice as possible.”

The study is published in Global Change Biology.