There might be something big living deep in Antarctica’s ice

Antarctica is one of the most extreme environments on earth. It is also one of the most unexplored regions.

Many of us think of the continent as a vast white wasteland, inhabited only by penguins and seals. But beneath its icy surface, scientists are beginning to discover vast networks of complex life forms not seen anywhere else on the planet.

There are two different types of Antarctic ice: land ice and sea ice. Sea ice forms when the upper layers of the Southern Ocean freeze over. The ice cover is seasonal, and in the summer most of this ocean ice melts.

A proliferation of photosynthetic algae has been observed in these areas once the snow melts. But until recently, it was often assumed that packed sea ice prevented any light from reaching the lower layers prior to this seasonal shift.

This stock image shows a frozen Antarctic landscape. Beneath the barren ice are ecosystems teeming with life.
Nico Elnino/Getty

However, new research indicates that a proliferation of photosynthetic algae, called phytoplankton, could grow and thrive before the ice recedes.

Phytoplankton form the basis of most aquatic food webs and support the growth of other complex life forms. Using data collected from NASA Earth observation satellites and ocean buoys at the site, researchers from Brown University and the University of Oakland have found evidence of vast swathes of photosynthetic life forms living beneath the frozen surface.

“Finding these blooms helps challenge the paradigm that regions below sea ice are devoid of life, and introduces important new questions about food webs that may lie beneath the ice in Antarctica,” said Christopher Horvat, who led the study published in the journal Nature. Frontiers in Marine SciencesTell Newsweek.

“We think it could cover up to 5 million square kilometers of subglacial area in the Southern Ocean.”

Sea ice in the Southern Ocean consists of separate sheets of packed ice. Between these leaves, small areas of open water allow light to pass through, allowing photosynthesis to take place.

Ice sea floe
This stock image shows the buoyancy of sea ice. The gaps between layers of sea ice allow light to seep into the water beneath.
pum_eva / Getty

Huw Griffiths, a marine geographer with the British Antarctic Survey, explained that the sea ice itself is usually about three to ten feet thick, and so also allows some light to reach directly into the surface waters below.

However, life has also been discovered in areas that have never before seen the light of day. “Most layers of ice are so thick that no light reaches the sea floor beneath,” Griffiths said. Newsweek.

Ice shelves consist mostly of the second type of Antarctic ice: terrestrial ice. They are formed when huge slabs of ice are pushed off the land onto the ocean’s surface. Unlike sea ice, these sheets can be thousands of feet deep.

In 2021, Griffiths and his team discovered marine life forms on a rock on the seafloor beneath the Antarctic ice shelf, 3,000 feet below the surface.

“We know very little about life beneath the floating ice shelves in Antarctica,” he said. “The ice shelves cover about a third of the continental shelf – 1.5 million square kilometers – but our knowledge is based on a small number of records from wells drilled through the ice shelves.” .

“These holes give us small snapshots of what lives on the sea floor and in the water column, but the majority of what we know comes from short videos and photographs covering a very small area.

He continued, “Current theories about what life might be surviving under the ice shelves indicate that all life becomes less abundant the farther away from open water and sunlight.”

“Previous studies have found some small scavengers and predators, such as fish, worms, jellyfish or krill, in these habitats. And our study found the first ever record of a hardy layer — a rock — community deep beneath the ice shelf, made up of potentially filter-feeding animals such as sponge.”

Moving inland, the frozen wastelands of Antarctica hide a hidden kingdom of hundreds of subglacial lakes and rivers, coexisting with life. In 2014, Lake Whillans, the third largest lake on the continent, which lies 2,600 feet below the ice sheet in West Antarctica, was found to contain nearly 4,000 different species of microbes.

In June, researchers from New Zealand recorded swarms of shrimp-like creatures in an underground river under the Ross Ice Shelf on the southern edge of the continent.

Taken together, these discoveries indicate just how diverse life forms can be under Antarctica’s ice.

“Animals that live deep in ice shelves need to adapt to extreme cold, with temperatures as low as -2.2 degrees Celsius (28 degrees Fahrenheit),” Griffiths said. “It would also need to adapt to smaller amounts of food, in a similar way to the creatures of the deep sea. These creatures live hundreds of kilometers from the nearest daylight and fresh phytoplankton sources.”

Such adaptations open up the possibility of similar ecosystems in other frozen landscapes.

Discovering complex animal life – more than [just] Microbes—in such extreme conditions suggest that complex life may be living beyond Earth on frozen moons, such as Jupiter’s Europa, Ganymede, and Callisto, planets where liquid water flows beneath the icy surface, Griffiths said.

Jupiter's moons
This stock image shows Jupiter and its moons. The discovery of life forms under Antarctic ice suggests that other complex organisms could also survive in similar extreme extraterrestrial environments, such as the frozen moons of Jupiter.
dottedhippo/Getty

But these studies also tell us about life on our planet.

“Antarctica is one of the most extreme environments on earth,” Griffiths said. “We have names for nearly ten thousand species but every time we visit, between 10 and 20 percent of the species we find are new to science. There could be as many as ten thousand more waiting to be discovered!”

“Working in Antarctica is never boring, always challenging and always surprising. It also requires an enormous amount of international cooperation – no single country can study this massive ice continent on its own,” he said.

As human impact extends to every corner of the planet, the untouched ecosystems of Antarctica are under threat. As a result of global warming, the Antarctic ice sheets are melting at a rate of nearly 150 billion tons annually, with catastrophic consequences for sea levels around the world.

“Antarctica faces many challenges in its future, with climate change and human impacts already altering the habitats we find there,” Griffiths said. “Ice shelves and sea ice are already changing, and sea water is getting warmer and more acidic. We’ve found microplastics in the water, sediment and animals, and other pollutants from industrialized nations have found their way into the Southern Ocean.

“Most people know less about Antarctica’s unique wildlife and biodiversity than about the penguins and seals that live on the surface. But more than 90 percent of Antarctic species are found on the sea floor and more than half are found nowhere else on Earth. .

“This makes Antarctica a special and globally important hotspot for biodiversity and somewhere that needs our help to stay healthy and able to support such an abundance of life.”

Do you have advice on a science story that Newsweek should cover? Do you have a question about Antarctica? Tell us at science@newsweek.com.


References

Horvat C. et al., Evidence for Phytoplankton Flourishing Under Antarctic Sea Ice, in Introduction. Science, 17 Nov. 2022, doi: 10.3389/fmars.2022.942799

Griffiths HJ, et al. , Breaking All the Rules: First Recorded Tough Tough Community Beneath the Antarctic Ice Shelf, in the forefront. Do science. February 15, 2021, https://doi.org/10.3389/fmars.2021.642040

Christner, B., Priscu, J., Achberger, A. et al. , A microbial ecosystem under the West Antarctic ice sheet, Nature, Aug. 20 2014, https://doi.org/10.1038/nature13667

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