Oceanography

Ocean deoxygenation has detrimental repercussions. Fish, crabs and other significant species of marine life that are unable to flee these low oxygen zones may perish as a result. People who depend on them for food and employment may be subsequently impacted by their absence as many of these species are economically significant.

Additionally, there is a negative feedback loop at play: as ocean oxygen levels decline, so does its capacity to absorb carbon dioxide. This may cause global warming to accelerate even further.

A study just published in Nature Communications suggests that the Atlantic Meridional Overturning Circulation (AMOC), of which the Gulf Stream is a part, could be approaching a tipping point. The AMOC, which has been gradually weakening over the last century and is reportedly at its weakest in over a millennium, could shift from its current strong mode to a weak one, with profound implications for the global climate.

While on a mission to map the volcanic geography of Cocos (Keeling) Islands Marine Park off Western Australia, researchers aboard the vessel Investigator also surveyed the deep-sea life in the Indian Ocean Territories.

In doing so, they came face-to-face with many fascinating, and some previously unknown, species.

Besides filming videos of the vast marine life amidst the summits of seamounts, the team also collected specimens from depths as deep as five kilometres below the surface.

We have discovered an amazing number of potentially new species living in this remote marine park

Dr Tim O’Hara, Chief Scientist of the expedition and Senior Curator, Marine Inveterbrates at Museums Victoria Research Institute

During the expedition, the researchers had been sharing their discoveries with more than 850 school students and community members in Australia through real-time livestreaming.

The expedition was a collaboration between Museums Victoria Research Institute and CSIRO, in partnership with Bush Blitz, Parks Australia, Australian Museum Research Institute and the Western Australian Museum.

More than 35 potentially new deep-sea species have been discovered at the Clarion-Clipperton Zone (CCZ) in the central Pacific. 

Ranging from starfish and segmented worms to sea cucumbers and various types of coral, these specimens were collected using a remotely operated vehicle.

In total, 55 benthic specimens were collected from seamounts and abyssal plains. Of these, 39 were found to be potentially new to science, with nine that were referable to known species. 

The dive was piloted by Victor Vescovo, undersea explorer and founder of the ocean research company Caladan Oceanic, with Dr. Dawn Wright (Chief Scientist at Esri) as mission sonar specialist. The expedition was again led and coordinated by expedition leader Rob McCallum, founder of EYOS Expeditions.

Wright supported the dive with her expertise in marine geology and the company's geospatial technology and became one of the few individuals – and the first Black person – to visit Challenger Deep.

On 21 January 2022, two men dived the first-ever crewed dive to the deepest point of the Atacama Trench, the deepest trench in the southeastern Pacific.

This feat saw explorer Victor Vescovo, Founder of Caladan Oceanic, and Osvaldo Ulloa from Instituto Milenio de Oceanografia (IMO) descending to 8,069m below sea level, in the submersible Limiting Factor. This dive was the first in the Chilean leg of the Ring of Fire Pt 2 (2022) expedition.

The hydrothermal vents are located in the Pescadero basin and are unique both in their chemistry and appearance to other known hydrothermal vents, as they are the only ones currently observed to emit clear fluids as opposed to dark, smokey fluids associated with iconic “black smoker” vents.

Indigenous names

The largest of the new vent mounds, named Maija awi, sits midway between the JaichaMaa ‘ja’ag vent field, discovered by the same team during Schmidt Ocean Institute’s 2018 R/V Falkor expedition, and the Auka vent field, discovered during an expedition by the Monterey Bay Aquarium Research Institute (MBARI) in 2015.

Most scientists think they came from water-rich asteroids and comets raining down on the planet in its youth. Just after the Earth formed, it was very hot and dry. Prevailing theory suggests that millions of water-rich comets and asteroids bombarded our planet around 3.8 billion years ago, neatly explaining why oceans later appeared.

Also, the ratio of deuterium—or “heavy hydrogen” because it contains a neutron in addition to a proton—to hydrogen in our sea water matches the value found in water-rich asteroids, suggesting a common origin.