Researchers discover that oxygen is made without photosynthesis – with stunning consequences

Oxygen, the molecule that supports intelligent life as we know it, is largely made by plants. Whether underwater or on land, they do this by photosynthesizing carbon dioxide. However, a recent study shows that oxygen can be produced without the need for life at depths where light cannot reach.

The authors of a recent publication in Nature Geoscience collected samples of sediments in the deep ocean to determine the rate of oxygen consumption on the seafloor through things like organisms or sediments that can react with oxygen. But in several of their experiments, they found that the amount of oxygen increased instead of decreasing as they expected. This made them wonder how this oxygen was produced.

They discovered that this “dark” oxygen production on the seabed only seems to happen in the presence of so-called mineral concentrates polymetallic nodules and deposits of metals called metallic sediments. The authors think the nodules have the right mixture of metals and are so tightly packed that an electric current can pass through them. electrolysiswhich creates sufficient energy to separate hydrogen (H) and oxygen (O) from water (H₂O).

The authors also suggested that the amount of oxygen created may fluctuate depending on the number and mix of nodules on the ocean floor.

This research team sought to understand the implications of mining deep-seabed metals, such as lithium, cobalt or copper, funded by an extractive company in an effort to ensure that deep-sea mining leads to a net benefit for humanity and humanity. Earth system. For example, lithium and cobalt are used to make rechargeable batteries for mobile phones, laptops and electric vehicles. Copper is vital for electrical wiring in appliances such as TVs and radios, and for roofing and plumbing.

The research was aimed at the Clarion-Clipperton zone of the Pacific Ocean, a vast plain between Hawaii and Mexico where millions of tons of these metals have been found. However, scientists believe that mining at this scale is potentially unpredictable and can be so destroy habitats crucial for ocean ecosystems. Deep-sea mining is also possible introducing harmful sediment plumes to fragile ecosystems, leading to a growing number of countries calling for a moratorium.

Dark oxygen for life

The implications of this finding may also play a role in life elsewhere.

Oxygen is essential for complex life as we know it. Complex life has evolved and expanded alongside photosynthesizers, which actually produce oxygen as a waste product. Yet this oxygen ensures that organisms metabolism much more efficient than without.

Without photosynthetic bacteria, life on Earth’s dependence on oxygen might never have occurred, along with the evolutionary path to biodiversity as we know it. However, this study shows that rich nodules on the seafloor may have provided an additional source of oxygen to the biosphere – the life zone on Earth that includes all living organisms.

We can’t understand how these nodules have influenced evolution until we understand more about how they formed deeper in time. At this point, all we know is that these nodules themselves would have needed oxygen to form.

Studies like these show how much of a mystery the origin of life on Earth remains.

This article was originally published on The conversation Through Lewis Alcott from the University of Bristol. Read the original article here.