"Mucus-Covered Jellyfish Hint at Dangers of Deep-Sea Mining"

"Shipboard experiments suggested that sediment from the exploitation of metals in the ocean could be harmful to marine life."

"A treasure trove of metal is hiding at the bottom of the ocean. Potato-size nodules of iron and manganese litter the seafloor, and metal-rich crusts cover underwater mountains and chimneys along hydrothermal vents. Deep-sea mining companies have set their sights on these minerals, aiming to use them in batteries and electronics. Environmentalists warn that the mining process and the plumes of sediment it would dump back into the sea could affect marine life.

A series of shipboard experiments on jellyfish in the Norwegian fjords, published Tuesday in the journal Nature Communications, offer insights into those warnings. The scientists approximated the effects of mining by pumping sediment into the jellies’ tanks, essentially asking how the animals would cope with the muddy water. The answer? Not well.

The researchers selected helmet jellyfish as their research subjects because of the ubiquity and hardiness of the dinner-plate-size creatures. The idea was to choose an organism that the team could easily get hold of “and then expose it to conditions that we expect in the mid-water in the open ocean,” said Helena Hauss, a marine ecologist at the Norwegian Research Center who conducted the study while working at the GEOMAR Helmholtz Center for Ocean Research Kiel in Germany."

Kate Golembiewski reports for the New York Times November 21, 2023.

Source: NYTimes, 11/22/2023