Shallow-water mining in direct conflict with sustainability goals

The paper, published in the journal Trends in Ecology & Evolution, points out that since mining in deep sea areas is considerably expensive, extracting nickel, cobalt and other battery metals from shallow marine areas has been proposed as a more sustainable solution to the increasing demand for materials needed for the green energy transition.

In detail, shallow-water mining takes place at depths less than 200 metres and it has been touted as less destructive than terrestrial mining and less risky than mining in poorly understood deep-water ecosystems. However, the authors of the study cast doubt on this assertion.

In the paper, they note that extracting gold, cobalt, copper, and phosphorites from the shallow-water ocean floor requires dredging large amounts of sediment. Removing this sediment, which takes thousands of years to accumulate, means removing the organisms that call it home.

“Mineral mining alters habitats as well as causes local biodiversity loss and changes in species communities. The indirect effects of mining, such as the spread of swirling seabed material and harmful substances released from the seafloor and the clouding of water, contribute to impairing the state of the marine environment,” the scientific team said in a media statement.

The researchers also mentioned the ecosystems of shallow marine areas are already in a weakened state, as human activity is concentrated in coastal areas.

In their view, the overall environmental effects of shallow-water mining are probably similar to those of operations where the seafloor is excavated, such as dredging. This means that it can take decades for the ecosystems to recover.

“The possible environmental effects are in conflict with the latest conservation and sustainability goals,” Elina Virtanen, second author of the study, said in a media statement. “The EU and the UN have an ambitious goal of protecting 30% of all marine areas, and EU directives include items on achieving a good status for marine areas.”

For Virtanen and her colleagues, the precautionary principle should be applied to mining in shallow marine areas. They believe operations should not be permitted until their risks have been fully mapped.

The scientists also warn that discontinuing mining operations in shallow marine areas can be challenging if they are initiated before the relevant legislation is drafted and enacted.

Shallow-water mining projects are already underway in Namibia and Indonesia, and projects have been proposed in Mexico, New Zealand, and Sweden.