Antarctic wildlife is being sunburnt: Hole in the ozone layer now lingers over the continent for more of the year - leaving seals and penguins exposed to dangerous levels of UV, study warns

It's well known that Earth's ozone layer offers a protective barrier from the sun's harmful rays.

Unfortunately, a famous hole in the layer exists over the Antarctic for a few months a year, letting in cancer-causing ultraviolet (UV) light. 

Now, researchers warn that the hole is lingering continent for several weeks longer, compared with four years ago. 

This means Antarctic wildlife such as seals and penguins are at greater risk of getting sunburnt, while other plants and animals are affected too. 

Animals can get cancer from UV radiation, just like humans, although fur and feathers offer some protection. 

Antarctic wildlife is being sunburnt: Hole in the ozone layer now lingers over the continent for most of the year, leaving seals and penguins exposed to dangerous levels of UV, a study warns

The ozone hole is a gap in the ozone layer - a layer in Earth's stratosphere containing a high concentration of ozone (O3), an odorless, colorless gas. Researchers say the hole is lasting longer. Maps of ozone area for September to December show how the ozone hole disappeared early in 2019 (November, top) but in 2020 extended into December (bottom) 

The new study was led by Sharon Robinson, climate change biologist and Antarctic researcher at the University of Wollongong in Australia. 

The researchers referred to NASA data from satellite instruments that monitor the ozone layer while compiling evidence on the effect of UV on various species. 

'If ozone holes last longer, summer-breeding animals around Antarctica’s vast coastline will be exposed to high levels of reflected UV radiation,' Robinson and colleagues say in The Conversation. 

'More UV can get through, and ice and snow is highly reflective, bouncing these rays around.' 

The ozone hole doesn't stay the same size throughout the year – in fact, it opens up and closes annually as the seasons and temperatures change. 

Usually, the ozone hole opens up around August and reaches its widest extent around October before closing again in late November. 

Fortunately, this is a period when most Antarctic animals and plants are protected by snow and sea ice cover. 

But the experts found that the hole is lasting longer – into summer – when this cover has melted, putting them at risk. 

What makes this worse is that December peak breeding season for many Antarctic animals. 

Adult penguins and seals have protective feathers and fur, but their young that are yet to grow this covering may be more vulnerable. Pictured, young Emperor penguins. The species is endemic to Antarctica

If the ozone hole forms in early spring (September-October, top), most Antarctic organisms are protected by sea ice and snow cover. But a late recovery of the ozone hole (November-December, bottom) means more UV reaches the Antarctic - and during peak breeding season for many marine birds, mammals and plants

READ MORE Ozone Hole has been 'remarkably massive' over the past four years 

Pictured, the ozone hole recorded on October 3, 2022

'Our new research found that instead of closing up during November it has stayed open well into December,' Robinson and colleagues say. 

'This is early summer – the crucial period of new plant growth in coastal Antarctica and the peak breeding season for penguins and seals.'  

Adult penguins and seals have protective feathers and fur, but their young that are yet to grow this covering may be more vulnerable. 

Meanwhile, Antarctic hairgrass, the cushion plant and various mosses emerge from under snow in late spring, meaning they will be particularly exposed to maximum UV levels.

Antarctic mosses actually produce their own sunscreen to protect themselves from UV radiation, but this comes at the cost of reduced growth.

And krill – the small marine crustacean – will dive deeper into the water when UV radiation is too high.

This could make survival more difficult for the penguins, seals, whales and other marine life that feed on them, the researchers point out. 

Antarctic krill (pictured) are a key species, supporting populations of penguins, seals, whales and other marine life

This figure shows the maximum UV index at Palmer Station in Antarctica each month, in both ozone hole (thick blue line) and normal (thin blue line) conditions. This is compared with an equivalent location in the Arctic (Barrow, Alaska) as well as a Californian location (San Diego). The blue area shows how the UV index has more than doubled in the ozone hole era

READ MORE UN claims ozone hole could be mended by 2040 

The ozone layer protects us from dangerous ultraviolet rays from the sun which can lead to long-term health issues, including sunburn and even skin cancer

As for what's been causing the hole to last longer, the team point to series of 'unusual events' between 2020 and 2023.

These include the record-breaking 2019-2020 Australian bushfires and the huge underwater volcanic eruption off Tonga. 

'Volcanoes and bushfires can inject ash and smoke into the stratosphere,' the team explain. 

'Chemical reactions occurring on the surface of these tiny particulates can destroy ozone.'

They also point to three consecutive years of La Niña, the weather phenomenon that causes cooler, wetter conditions.

The academics 'don’t know for sure' what type of damage increased UV exposure will be doing to Antarctic species, because most research in this area has been done in zoos.  

They also don’t know if the longer-lasting ozone hole will continue. 

The new study, published in the journal Global Change Biology, adds to concerns over the ozone hole's overall size. 

Another team of experts recently warned that the ozone hole has been 'remarkably massive' over the past four years.

In the stratosphere is the ozone layer, a thin region that absorbs almost all of the sun's harmful ultraviolet light

It wasn't until the 1980s that the ozone hole was first discovered, by British meteorologist Jonathan Shanklin. 

The hole – which hit the global headlines – was created by the release of human-made chemicals, particularly CFCs (chlorofluorocarbons), into the atmosphere. 

This discovery led to the Montreal Protocol, an international agreement to halt the production of CFCs, signed in December 1987, and mend the hole. 

The UN has said that the ozone hole could be mended by 2040 largely due to the ban on CFCs, which are still lingering in Earth's atmosphere. 

However, climate change may be delaying the recovery of our ozone layer by, for example, making bushfires more common and more severe, the authors of this new study warn.  

'Although the ozone layer is expected to recover before the end of the 21st century, a hole over Antarctica continues to appear each year,' they say.

'Climate change, including changing wind patterns and strength, and particularly declining sea ice, are likely to compound UV-B exposure of Antarctic organisms, through earlier ice and snowmelt, heatwaves and droughts.' 

The Ozone layer sits in the stratosphere 25 miles above the Earth's surface and acts like a natural sunscreen

Ozone is a molecule comprised of three oxygen atoms that occurs naturally in small amounts. 

In the stratosphere, roughly seven to 25 miles above Earth's surface, the ozone layer acts like sunscreen, shielding the planet from potentially harmful ultraviolet radiation that can cause skin cancer and cataracts, suppress immune systems and also damage plants. 

It is produced in tropical latitudes and distributed around the globe. 

Closer to the ground, ozone can also be created by photochemical reactions between the sun and pollution from vehicle emissions and other sources, forming harmful smog.

Although warmer-than-average stratospheric weather conditions have reduced ozone depletion during the past two years, the current ozone hole area is still large compared to the 1980s, when the depletion of the ozone layer above Antarctica was first detected. 

In the stratosphere, roughly seven to 25 miles above Earth's surface, the ozone layer acts like sunscreen, shielding the planet from potentially harmful ultraviolet radiation

This is because levels of ozone-depleting substances like chlorine and bromine remain high enough to produce significant ozone loss. 

In the 1970s, it was recognised that chemicals called CFCs, used for example in refrigeration and aerosols, were destroying ozone in the stratosphere.  

In 1987, the Montreal Protocol was agreed, which led to the phase-out of CFCs and, recently, the first signs of recovery of the Antarctic ozone layer. 

The upper stratosphere at lower latitudes is also showing clear signs of recovery, proving the Montreal Protocol is working well.

But the new study, published in Atmospheric Chemistry and Physics, found it is likely not recovering at latitudes between 60°N and 60°S (London is at 51°N).

The cause is not certain but the researchers believe it is possible climate change is altering the pattern of atmospheric circulation - causing more ozone to be carried away from the tropics.

They say another possibility is that very short-lived substances (VSLSs), which contain chlorine and bromine, could be destroying ozone in the lower stratosphere.

VSLSs include chemicals used as solvents, paint strippers, and as degreasing agents.

One is even used in the production of an ozone-friendly replacement for CFCs.