It will take decades for the ocean floor to recover from human undersea mining

Because of the need for metals such as copper, nickel, and cobalt, some countries have turned to large areas of metal-rich rocks, called “polymetallic fossils” in the Atlantic to conduct mining. . However, there have not been many studies focusing on the impact of this activity on the sea bed ecosystem. A new work, published on Wednesday, on Science Advances, investigated a mining area off Peru and pointed out its long-term effects on the foundations of the food chain in communities. undersea creature.

A sponge stuck on polymetallic agar

In 1989, scientists conducted a “disturbance and recombinant experiment” (DISCOL) to evaluate the effects of deep-sea mining activities to collect “polymetallic agar”. They plowed and disturbed the 9-meter-wide sediment in the ocean floor deeper than 4.1 km below the surface of the ocean, then observed changes in the area after their activity.

Back to the present day, the team of researchers led by Tobias Vonnahme at the Max-Planck Institute of Marine Microbiology in Germany has returned to the region to compare the microbial activity in the plows they have made. in the DISCOL experiment above compared to both recently disturbed areas and undeveloped ocean floor areas, through images and samples taken from both remote and self-propelled vehicles. onions under the sea.

Do you know what happened?

The furrows in the DISCOL experiment after 26 years are still visible

Even after 26 years, DISCOL trenches are still visible in photographs taken by undersea vehicles. The researchers also observed a decrease in biological activity in both the new and 26-year-old plows. The total number of microorganisms that have been destroyed by half is by new plows, while at DISCOL plows, the number of microorganisms is 30% lower than the original. The researchers estimated that microbial activity in the plow will take up to 50 years to recover to its original state.

Although there are still positive signs, as the biological activity has recovered a bit, but the research has pointed to the more worrying issues when considered together with other relevant research data. Last year, scientists when analyzing the DISCOL area found that the number of suspension organisms – the animals that feed on fish floating in the water – had declined significantly, and biodiversity was reduced. Overall, the plowing areas also decreased. Research published on this Nature page concludes that ” the effects of polymetallic fossil mining activities may be greater than anticipated, and are likely to lead to irreversible losses to some ecosystem functions, especially in areas that are directly disturbed “.

The effects on the number of seabed bacteria are particularly noticeable. They are essentially the first level of food webs for the seafloor community. Researchers who did not participate in the study also agreed with the importance of the latest conclusions.

” If undersea mining continues, it will take place on a larger scale of space and time, with greater intensity than this experiment ” – Diva Amon, marine biologist and scientist studied at the Natural History Museum in England. That means the recovery process will take even longer.

Amon’s own work has found that more than 50% of the large undersea creatures depend on these rock formations for mooring, so “considering the millions of years of fossils forming, The prognosis for the resilience of this community is very low . ”

A polymetallic agar

Daniel Jones, Deputy Head of the Marine Ecology and Biology Group at the UK National Oceanographic Center, agrees that the DISCOL study has been conducted extensively and is followed by a group of scientists. learn world class. But he warns that the DISCOL study area is different from the Clarion-Clipperton Area (CCZ), where the seafloor mining activities take place the most – CCZ has less food resources than the Peruvian basin.

” It would be valuable to know how DISCOL findings compare to those found in areas directly affected by mining, ” he said. ” Hopefully we won’t have to wait too long, a series of new projects have been planned to address the challenge at CCZ .”

The data obtained suggests that the seabed mining can bring negative, and potentially irreversible, effects on the fragile oceanic ecosystems. The International Seabed Authority is considering issuing regulations governing the operation of the seabed mining, and then the mining companies can start extracting the desired minerals. But scientists are concerned that mining may start before we truly know the impact it will have. And many studies show that these effects will not be very good!

Reference: Gizmodo