Marine Biologists Find Coral Gardens in Deep-Sea Canyons Off Australia

A team of biologists led by University of Western Australia researchers used Schmidt Ocean Institute’s deep-sea remotely operated vehicle, SuBastian, which is capable of sampling depths to 4,500 m, to explore the Bremer, Leeuwin and Perth submarine canyons.

Coral garden found in Bremer Canyon, Western Australia as part of a month long expedition exploring canyon depths for the first time with ROV SuBastian. Image credit: Schmidt Ocean Institute.

Dr. Julie Trotter, the Chief Scientist from the University of Western Australia who led the expedition, and colleagues collected deep-sea corals, associated fauna, seawater, and geological samples from the abyssal depths (4,000 m) to the continental shelf (200 m).

“We have already made a number of remarkable discoveries from the Bremer Canyon,” Dr. Trotter said.

“The vertical cliffs and ridges support a stunning array of deep-sea corals that often host a range of organisms and form numerous mini-ecosystems.”

The discoveries are being integrated into a comprehensive package of biological, geological, and bathymetric data.

Such rare records of these deep-sea habitats are a new and very important contribution to the Marine Parks, which will help managers as well as the broader community to better understand and protect these previously unknown ecosystems.

The deeper waters in the three oceans that surround Australia, including the world’s largest barrier reef and submarine canyons, are largely unexplored.

“This has global implications given these waters originate from around Antarctica which feed all of the major oceans and regulate our climate system,” said Professor Malcolm McCulloch, also from the University of Western Australia.

“Australia has only one oceanographic vessel available for scientific research and no supporting deep sea underwater robots, which makes this expedition so important and rare,” the scientists said.

“Facing the Southern Ocean, the Bremer Canyon provides important information on the recent and past histories of climate change and ocean conditions in this region, as well as global scale events.”

“Because the Southern Ocean completely encircles Antarctica, it is the main driver of the global climate engine and regulates the supply of heat and nutrient-rich waters to the major oceans.”

“A particular species of solitary cup coral was found during the expedition,” said Dr. Paolo Montagna, co-chief scientist from the Institute of Polar Sciences in Italy.

“This is significant because we are working on the same coral in the Ross Sea on the Antarctic shelf, in much colder waters.”

“This is an important connection between disparate sites across the Southern Ocean, which helps us trace changes in water masses forming around Antarctica and dispersing northward into the Indian and other oceans.”