Thanks to a mechanism called the Antarctic convergence (in which cold water flowing north clashes with warmer, south-flowing water), the currents leaving the Southern Ocean are remarkably rich in nutrients. That makes the submarine canyons of South Australia a hotspot for migrating animals. Bremer Canyon, for example, is home to the Southern Hemisphere's largest seasonal gathering of killer whales and often hosts traveling sharks, dolphins, squids and birds, the researchers said.
During their latest expedition, the crew of the Falkor learned that these canyons are bustling with life deep underwater. Each spot hosted lush gardens of coral, rich with marine life and bursting with color. However, each canyon (especially Leeuwin) also contained extensive pockets of dead and fossilized coral. According to the researchers, these corals bear the record of both recent, anthropogenic ocean warming, as well as longer-term changes to the world's climate. It's not clear yet what killed the coral in a given canyon, but researchers will begin answering that question as soon as Falkor returns to land.
This voyage was funded by the nonprofit Schmidt Ocean Institute, and the team's newest research has yet to appear in a peer-reviewed journal.
Originally published on Live Science.