Honolulu: Waste plumes from deep-sea mining in the Pacific Ocean could starve key marine life and unravel entire food webs in the ocean's dim 'twilight zone,' according to a groundbreaking study published Thursday in Nature Communications. The study, led by researchers at the University of Hawai'i at Manoa's School of Ocean and Earth Science and Technology (SOEST), is the first to demonstrate how mining discharge-plumes of fine particles released into midwater during mineral extraction-endangers the food sources that sustain life between 200 and 1,500 meters below the surface.

According to Anadolu Agency, lead author Michael Dowd, an oceanography graduate student at UH Manoa, explained that when waste released by mining activity enters the ocean, it creates water as murky as the mud-filled Mississippi River. This murkiness poses a threat to zooplankton, which are exposed to so-called junk food sediment, potentially disrupting the entire food web. Researchers found that 53% of zooplankton and 60% of micronekton species, which feed on them, could be affected. The waste particles contained far fewer amino acids-essential for marine nutrition-than naturally occurring food sources.

Co-author Erica Goetze, professor of oceanography at SOEST, emphasized that the issue extends beyond mining the seafloor, highlighting the reduction in food for entire communities in the deep sea. The study specifically points to the Clarion-Clipperton Zone (CCZ), a vast Pacific area rich in minerals such as cobalt and nickel, now under roughly 1.5 million square kilometers of active mining licenses. Discharging mining waste into the twilight zone-a layer critical for global carbon cycling-could cause cascading ecological harm.

Deep-sea ecologist and co-author Jeffrey Drazen compared the situation to dumping empty calories into a system that's been running on a finely tuned diet for hundreds of years. With commercial mining still in its infancy, the authors stressed the urgency of regulation. Brian Popp, SOEST professor of earth sciences, warned that without understanding what's at stake in the midwater, there is a risk of harming ecosystems that are only just beginning to be studied.

The research team hopes the findings will guide global rulemaking by the International Seabed Authority and the US National Oceanic and Atmospheric Administration, emphasizing the need to manage mining waste with full awareness of its deep-sea impacts.