The expedition, which is expected to end February 14, is being led by the Japan Agency for Marine Earth Science and Technology, which did not respond to a request for comment. It comes three months after the country signed an agreement with the United States to collaborate on securing a supply of critical minerals.

Japan’s foray into deep-sea mining comes amid mounting concern about the ecological cost of such technology. Scientists and environmental groups warn that marine extraction is racing ahead of our understanding of the impacted ecosystems. They are particularly concerned about sediment plumes, noise and light pollution, and damage to habitats and food webs, noting that scars left by equipment could render the seafloor uninhabitable for decades, even centuries.