World’s Largest Fish Nesting Ground With 60 Million Nests Discovered Under Antarctic ice

The fact that we know less about the ocean floor than we do about the surface of the Moon doesn’t make this incredible find any less surprising. Five hundred meters below the ice covering the south of Antarctica’s Weddell Sea, a research team recently discovered the world’s largest fish breeding site known to date.

According to a new study published in Current Biology, an estimated 60 million active nests of Jonah’s icefish (Neopagetopsis ionah) stretch across a vast area of at least 240 square kilometers. The discovery was facilitated by a towed camera system led by the German research vessel Polarstern.

Until now, researchers have encountered only a handful of icefish nests at a time, or perhaps several dozen. Even the most gregarious nest-building fish species were previously known to gather only in the hundreds (other such species include the artistically inclined pufferfish, and freshwater cichlids).

Deep sea biologist Autun Purser of the Alfred Wegener Institute in Bremerhaven, Germany, and colleagues stumbled across the massive colony in early 2021 while on a research cruise in the Weddell Sea, which is located between the Antarctic Peninsula and the main continent.

According to their findings, the icefish probably have a substantial and previously unknown influence on Antarctic food webs.