Discovery of vibrant deep-sea life prompts new worries over seabed mining

A new species of the sea-anemone-like Relicanthus clings to a sponge stalk on the floor of the Pacific Ocean. Image courtesy of D.J. Amon & C.R. Smith.

Deep in the eastern central Pacific Ocean, on a stretch of sea floor nearly as big as the continental United States, researchers are discovering species faster than they can name them. And they are exploring newfound fossil beds of whales that lived up to 16 million years ago. The findings — many reported for the first time rcently at the Deep-Sea Biology Symposium in Monterey, California — have come as a shock. Some scientists had thought these vast underwater plains, 4,000–5,500 metres below the ocean surface, were relatively lifeless. But that is changing just as nations and corporations prepare to mine this patch of the Pacific sea bed for cobalt, manganese and other elements for use in technologies such as smartphones and electric cars.

Researchers are now pushing the International Seabed Authority (ISA), the body that oversees mining in international waters, to limit environmental damage from future activity. The ISA, which is developing rules for mining in the ocean, is accepting comments on a draft plan until 30 September. Its goal is to release final rules by 2020, clearing the way for mining to start.

Seafloor surveys are just beginning to map the vibrant life in areas marked for mining. Craig Smith, a professor in the Department of Oceanography, helped lead expeditions in 2013 and 2015 to a territory in the eastern CCZ claimed by the United Kingdom. He was surprised to find hills and mountains rising across deep undersea plains. The landscape was teeming with life more diverse than that seen at similar depths elsewhere.

Read more about it in Nature News.