Major icefish breeding colony discovered beneath Antarctic seas

New Delhi : A researcher has discovered an icefish breeding colony more than 1,000 feet below the icy ceiling at the surface of the Weddell Sea. 

Lilian Boehringer, a student researcher at the Alfred Wegener Institute in Germany, has spotted the nest. The sandy craters dimpled the seafloor, each the size of a hula hoop and less than a foot apart. Each crater held a single, stolid icefish, dark pectoral fins outspread like bat wings over a clutch of eggs.

The icefish flourishes just above the freezing point and have transparent blood as they do not have red blood cells to carry oxygen throughout the body. Icefishes’ loss of hemoglobin genes was less an evolutionary adaptation than a happy accident, one that has allowed them to absorb the oxygen-rich Antarctic waters through their skin.

The nest was spotted in February 2021 with the help of a camera connected to a research ship, the Polarstern, which had come to the Weddell Sea to study other things, not icefish.

At around 3 AM when the sun was bright, Boehringer noticed that the camera was transmitting pictures as it moved with the ship, revealing an uninterrupted horizon of icefish nests every 20 seconds.

“It just didn’t stop,” Boehringer said. “They were everywhere.”

After almost 30 minutes, Autun Purser, a deep-sea biologist at the same institute, joined Boehringer. On the camera feed, there remained nothing but nests.

“We were like, is this ever going to end?” Purser said. “How come no one has ever seen this before?”

The nests continued for around four and a half hours, measuring about 60 million nests. The researchers described the site — the largest fish breeding colony ever discovered — in a paper published Thursday in the journal Current Biology.