They discovered that the ocean floors produce their own oxygen.

The blueprint for our planetary biology is clear: only photosynthetic organisms like plants and algae produce oxygen on Earth. But science (and life) They always know how to surpriseNow a team of scientists led by Andrew Sweetman has discovered that metallic minerals on the deep ocean floor are producing oxygen at depths of about 400 metres.

The surprising discovery challenges long-held assumptions that only photosynthetic organisms such as Plants and algae produce the Earth’s oxygenAccording to the study, published in the journal Nature Geoscience, oxygen may also be produced on the seafloor, where light cannot penetrate, to support marine life that breathes oxygen (aerobically) and lives in complete darkness.

Sweetman’s team performed discovery of “dark oxygen” conducting field work from a boat in the Pacific Ocean, and Franz Geiger of Northwestern University led electrochemical experiments that potentially explain the discovery.

“For aerobic life to have arisen on a planet, there had to be oxygen, and we have always thought that the Earth’s oxygen supply began with photosynthetic organisms,” Sweetman explains in a statement. But We now know that oxygen is also produced in the deep sea, where there is no light.

. So I think we need to rethink questions like: Where could aerobic life have originated?

The discovery is based on polymetallic concretions (natural mineral deposits that form on the ocean floor). Formed by a mixture of several minerals. Nodules are measured between the smallest particles and the average potato size..

“The polymetallic nodules that produce this oxygen contain metals such as cobalt, nickel, copper, lithium and manganese, all of which are critical elements used in batteries,” adds Geiger, a co-author of the study. Several major mining companies are now seeking to to extract these precious elements from the seabed at depths of 3,000 to 6,000 meters.“We need to rethink how we mine these materials so we don’t deplete the oxygen supply for life in the deep sea.”

The authors made the discovery while sampling the seafloor of the Clarion-Clipperton Zone, an underwater ridge that stretches more than 6,000 kilometers.in the northeastern Pacific Ocean. When your team oxygen was initially detected, it is assumed that the equipment is broken

.

“When we first got this data, we thought the sensors were faulty because every study we’d done in the deep sea had shown that oxygen was being consumed, not produced,” Sweetman says. “We’d go home and recalibrate the sensors, but for 10 years, these weird oxygen readings kept coming up. We decided to use a backup method that worked differently than the sensors we were using. When Both methods gave the same result, we knew we were onto something innovative and unthinkable.“.

But there’s more to the deep than oxygen and life. In a previous study, Geiger found that Rust combined with salt water can generate electricity. Researchers wondered whether polymetallic nodules in the deep ocean generate enough electricity to produce oxygen. This chemical reaction is part of a process called seawater electrolysis, which removes electrons from water’s oxygen atoms.

It takes just 1.5 volts (the same voltage as a typical AA battery) to split seawater, and Sweetman’s team measured voltages as high as 0.95 volts on the surface of individual nodules. And when several nodules are grouped together, The voltage can be much higher, for example when batteries are connected in series.

“It appears that we have discovered a natural ‘geobatteries’,” Geiger confirms. “These geobatteries are the basis for a possible explanation for the formation of dark oxygen in the ocean.”

Researchers agree that The mining industry should consider this discovery. before planning deep sea mining.

“In 2016 and 2017, marine biologists visited sites mined in the 1980s and found that not even bacteria were found in the mined areas,” Geiger concludes. “However, in the unmined areas, marine life was thriving. It is not yet known whether these “dead zones” will persist for decades.. However, this calls into question seabed mining strategies, as the diversity of ocean floor fauna in nodule-rich areas is greater than in the more diverse tropical forests.”