Surface of Seabed Manganese Nodule from South Korea
There are trillions of potato-sized metal nodules on the floor of the ocean around the world.
Some of these nodules are being explored for economic potential. A major vote by a UN body on the commercial exploitation of these minerals is planned in October 2020 (postponed from July 2020).
However, the formation of these metallic nodules is radically different from the processes used to create such metals on land i.e., they are biological in origin rather the geological.
This has profound implications for what the true value of life around these metallic nodules could be.
How nodules are formed
There are several theories for how seabed nodules form. They are not geological in origin, unlike the formation such metals on land.
First, a biological process (such as the remnant of a shark tooth) falls to the ocean floor. This forms the basis around which microorganisms gather.
These microorganisms have developed processes over millions of years to extract trace metals from the seawater. These biological processes catalyze the chemistry needed to form and grow seabed nodules.
Seabed Nodules grow at an incredibly slow rate of 10 millimeters every million years. Once these nodules are removed, they will never reoccur within human timescales.
It has also been shown recently that these nodules are home to unique metal-metabolizing microorganisms that have not just been found on the surface of nodules, but within them too.
These microbes may play a role in the nodule’s formation and degradation, and can be very valuable for cleaning up polluted areas (bioremediation).
In other seabed locations that are being considered for mining, such as manganese seabed crusts, diverse microbial communities have been discovered that are not found anywhere else.
These communities vary significantly between deep-sea locations.
Since less than 0.05% of the deep seabed has been visited, imaged or sampled, numerous unknown organisms, including ones that can only live on or within metallic nodules and crusts, are at risk of extinction as a consequence of the proposed mining.
Farming rather than mining
Several major chemical and pharmaceutical companies already see the value of marine genetic resources.
There are 13,000 patents created around marine genetic resources, almost half of which are owned by German chemicals giant, BASF.
Several countries have been calling for a new UN Treaty called the Treaty on Biodiversity Beyond National Jurisdiction to ensure such microbial biodiversity is recognized and protected in the high seas.
There have been many significant advances in synthetic biology in recent years. eDNA has allowed scientists to learn more about species who inhabit the deep ocean, without even needing to see these species.
Other discoveries in synthetic biology, such as CRISPR Cas-9, can help read, edit, write and print genomes, perhaps catalyzing a new marine bioengineering industry.
Already, several large companies have developed that use biology from land for use as novel clothing with steel-like strength, mushroom-grown handbags, or wood made without trees that can be used for musical instruments.
As the world is on the cusp of a new biological revolution, it is important to understand the importance of life across all areas of the planet.
These advances could mean that one day, it may be more valuable to be farming metals from giant oceanic biorefineries using microorganisms from the deep ocean, rather than extracting the metal byproduct using strip mining techniques and placing these valuable microorganisms in danger.