Over 1,000 geometric fish nests found in the Weddell Sea signal VMEs

Researchers exploring the Western Weddell Sea in 2019 discovered more than 1,000 neatly cleared, circular fish nests arranged in repeating geometric patterns on the seafloor, a finding that adds to evidence of previously hidden, biologically rich habitat beneath Antarctica’s shrinking ice shelves. The nests, filmed by a remotely operated vehicle during the Weddell Sea Expedition aboard the South African research vessel SA Agulhas II, were located in an area opened to survey after the A68 iceberg calved from the Larsen C Ice Shelf in 2017.

The footage, examined after the expedition, showed nests belonging to the yellowfin notie Lindbergichthys nudifrons, a species of rockcod adapted to frigid Antarctic waters. Each nest appeared cleared of the surrounding plankton detritus and was occupied and guarded by a parent fish. The nests formed distinct arrangements including clusters, crescents, U shapes, lines and ovals, rather than the random scatterings scientists might otherwise expect. The discovery is described in a study published October 29 in Frontiers in Marine Science.

Lead study author Russell Connelly of the University of Essex said the team initially debated the nests’...