The release of particles as a result of deep-sea mining operations could have severe detrimental effects on deep-sea fauna, new research has found.
In a study published in Deep Sea Research Part I: Oceanographic Research Papers, scientists at Wageningen University & Research in the Netherlands and the University of Bergen in Norway simulated the effects of mining plumes by exposing the common deep-sea sponge Geodia barretti and its associated brittle star species from the genus Ophiura to a field-relevant concentration of suspended particles made from crushed seafloor massive sulphide (SMS) deposits.
SMS deposits are large three-dimensional, geological formations at the sea floor and a primary target for deep-sea mining because they contain large amounts of valuable metals.
The study revealed a tenfold increase in tissue necrosis in the sponges following exposure to suspended SMS particles, while all brittle stars in the experiment perished within 10 days of exposure, probably due to toxic metals. Concentrations of iron and copper were found to be 10 times higher in SMS-exposed sponges, demonstrating the accumulation of the suspended mining particles in the tissues of these filter-feeding animals.
“These results underscore the urgent need for comprehensive assessments of deep-sea mining impacts on marine ecosystems,” research lead Erik Wurz said in a media statement. “The adverse effects observed on Geodia barretti and associated species signal potential disruptions in benthic-pelagic coupling processes, necessitating further research and establishing guidelines for the protection of this deep-sea fauna.”
Wurz pointed out that it has recently been shown that large swaths of the deep ocean seafloor in the North Atlantic Ocean are very prolific, sponge-dominated ecosystems rather than barren deserts, which is generally assumed.
“By showing the impact of mining particles on these sponge grounds, the study underscores the need for sustainable management practices to mitigate the adverse effects of mining on this marine biodiversity,” the researcher said.