Breeding Grounds

Behold! Scientists reveal fish nest network 4 times the area of Manhattan under Antarctic ice

OK, then.

by Jennifer Walter
Alfred Wegener Institute / PS124 AWI OFOBS team

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Despite near-freezing water, the Weddell Sea off the coast of Antarctica is teeming with life.

Alfred Wegener Institute / PS124 AWI OFOBS team

Creatures like sea spiders, sea cucumbers, and myriad species of fish have adapted to life in this extremely dark, cold climate.

One fish seems to be thriving more than previously thought.

Researchers surveying the southern Weddell Sea found a network of 60 million active nests belonging to the ice fish Neopagetopsis ionah.

Alfred Wegener Institute / PS124 AWI OFOBS team

Alfred Wegener Institute / PS124 AWI OFOBS team

This breeding colony spans up roughly 92.5 square miles of seafloor, researchers report in the journal Current Biology.

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It’s the largest continuous colony of nesting fish ever discovered.

Study author and deep-sea biologist Autun Purser says the finding was a complete surprise.

Patricia Hamilton/Moment/Getty Images

“The very existence of such a huge, unreported breeding colony was the most surprising discovery, and the fact that so much seafloor biomass was hidden here below the Antarctic sea ice.”

Purser tells Inverse.

In this footage, dozens of fish are seen guarding their nests against predators, Purser says. Each nest contains about 1,700 eggs.

Alfred Wegener Institute / PS124 AWI OFOBS team

Alfred Wegener Institute / PS124 AWI OFOBS team

“Experts inform us the adult fish look quite thin, so we are thinking they basically fatten up before guarding the eggs, and don’t leave the eggs if they can help it.”

Purser, to Inverse

The fish seem to be a key part of the Antarctic ecosystem. There are about 60,000 tons of them, after all.

Even large predators like seals will make a meal of them.

Mia Wege / PS124 seal team

Alfred Wegener Institute / PS124 AWI OFOBS team

Purser says there is still much unknown about the lives of N. ionah — and life on the Antarctic seafloor.

AWI - Tim Kavelage

He plans to make another trip to the Weddell Sea this year to study areas north of the fish breeding grounds to compare changes over time.

It’s important data to gather in the face of climate change, he says.

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As the Earth warms, ice cover and ocean flow conditions could alter life in the ocean’s most remote ecosystems.

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“We know very little about the deep sea seafloor, and even as the James Webb Telescope gets to work on the cosmos, plenty of finds are still to be made here on Earth.”

Purser, to Inverse