Disturbing sediments and life on the ocean floor could worsen climate change, iC3 researcher finds

Disturbance of the seabed, for example by deep-sea mining, could increase the scale and speed of climate change, a new study published today by a team of researchers indicates. The scientists systematically surveyed animals living at 17 different sites on the Arctic ocean floor and found that they are storing a far larger amount of carbon than previously believed. 

Dr Terri Souster, manager of the iC3 polar research centre and the study’s lead investigator, said:

“Previous estimates have underestimated how much carbon is being removed by marine life because they were based on data from troughs on the ocean floor. We systematically assessed a wider range of seafloor sites and found that far more carbon is being removed in shallower areas.” 

Seafloor creatures such as corals, star fish, and sponges extract carbon from the surrounding water to grow and build their shells and skeletons. Once they die, their shells and skeletons are buried in sediments on the ground of the ocean, permanently locking away much of the carbon they contain. By disturbing or even destroying these habitats, deep sea mining and trawling could reduce the oceans’ natural ability to remove carbon from the atmosphere and thereby act as a brake on climate change.

During the 2022 United Nations biodiversity conference, governments agreed on a target of protecting at least 30 percent of the world’s waters by 2030.

Dr David Barnes from the British Antarctic Survey, who contributed to the study, said:

“This study highlights how little we know about functionality of life in the deep, how it affects the global carbon cycle, and the benefits nature in the ocean brings society. We do not know which deeper seabed areas store most carbon, so we do not know what areas we need to prioritise for conservation. Commercial exploitation is racing ahead before we even know what we will be damaging and losing.” 

The study, which spanned 17 sites in the Barents Sea north of Norway, is likely to inform current political debates about bottom trawling and deep-sea mining. Earlier this month, Norway became the first country in the world to move forward with commercial-scale deep-sea mining, inviting companies to apply for mining permits in its national waters. Supporters of the practice argue that it is a cheaper and less environmentally harmful than opening up new mines on land to meet the world’s growing demand for rare minerals that are crucial for the green energy transition.

While some governments have called for an international moratorium on seabed mining until scientific gaps have been filled, others have started taking steps towards launching mining operations of their own. The International Seabed Authority is currently drafting regulations that could eventually allow seabed mining in international waters. 

The new iC3 polar research centre produces ground-breaking insights into how the links between ice sheets, carbon cycles and ocean ecosystems are impacting life on earth. It is rapidly growing its team, with five fully funded PhD positions now open for applications. 

In parallel, iC3 is inviting postdoctoral researchers to join the team through the Marie Curie (MSCA) postdoctoral fellowship programme. Selected postdocs applying in tandem with iC3 researchers will benefit from the Arctic MSCA Support Programme, which doubles applicants’ success rate in securing MSCA funding. iC3 is housed by UiT The Arctic University of Norway, which has the world’s highest volume of Arctic-related research output, and is partnered with the Norwegian Polar Institute and NORCE.