A treasure trove of metals lies at the bottom of the ocean. Potato-sized chunks of iron and manganese litter the ocean floor, and a metal-rich crust covers underwater mountains and chimneys along hydrothermal vents. Deep-sea mining companies are eyeing these minerals for use in batteries and electronic devices. Environmentalists have warned that the mining process and the plumes of sediment dumped into the ocean could affect marine life.
A series of shipboard experiments on jellyfish in the Norwegian fjords, Published Tuesday in Nature Communications, provides insight into these warnings. The scientists estimated the impact of mining by pumping sediment into jelly tanks, essentially asking how animals would cope with the muddy water. answer? not good.
The researchers chose the horseshoe jellyfish for their study because the dinner-plate-sized creatures are ubiquitous and hardy. Helena Haus, a marine ecologist at the Norwegian Research Center, said the idea was for the research team to select an organism that was readily available, “and then expose it to conditions that would be expected in midwaters of the open ocean.” Ta. This research was carried out while working at the GEOMAR Helmholtz Marine Research Center in Kiel, Germany.
This jellyfish is found in waters 1,500 to 2,000 feet deep around the world and serves as a representative of the myriad soft-bodied animals that live in the open ocean that can be affected by mining.
The researchers captured the jellyfish, which are abundant in Norway’s fjords, in fine-mesh nets, carried them below deck on a research vessel, and studied them in a dimly lit room lit with red light.
“They’re really adapted to living in eternal darkness,” says study author Vanessa Stembers, a doctoral candidate at GEOMAR. “That’s why we had to be very careful when observing them and always use a red light so as not to disturb them.”
The scientists exposed the jelly to plumes of sediment similar to those experienced around deep-sea mining sites. He could see only one reaction from the jellyfish with the naked eye. They tried to remove the deposits by producing extra mucus, which Stenvers likened to frost.
Other stress responses occurred at the molecular level, with activation of several genes related to tissue repair and the immune system.
“One of the things that concerns me is that everything these animals do to remove sediment or fight pathogens requires energy,” Dr. House said. Told. Food is scarce in the deep ocean where jellyfish live, and coping with the effects of muddy water may require more energy than the jellyfish get from their diet. “It can lead to starvation and reduced reproductive rates,” House says.
Jeffrey Drazen, a marine biologist at the University of Hawai’i at Manoa who was not involved in the study, said: “This is a really welcome study, given the large amounts of sediment that can be released by deep-sea mining.” ” he said. “This is the first study to examine the response of water column animals to mud,” he says.
Dresen noted that the species the researchers chose for their study was more hardy than many of its relatives. “This is a really hardy jellyfish. You can catch this with a net, but it doesn’t turn into goo,” he says, adding that the stress response to sediment is similar to that of other soft jellyfish exposed to sediment for long periods It shows that the marine life in your body could be in a much worse situation.
The researchers say their findings suggest that deep-sea mining can have negative impacts not only on marine life but also on human life. Meso-sea animals like the horseshoe jellyfish contribute to biological cycles that store carbon deep in the ocean rather than in the atmosphere. Fish such as tuna, which humans depend on for food, feed on these mid-sea communities.
“Even if we don’t deal with this issue on a daily basis, even in athletics, it’s very important to us,” Stenbers said. The benefits that the open ocean brings to our planet “could be lost if we don’t protect it.”