The rush to find the minerals needed to power our batteries and other electronics has mining companies looking to the seafloor—but at what potential cost to the marine life that lives above it? A study published Tuesday in Nature Communications aimed to answer that question using jellyfish, and as the New York Times‘ headline on it declares, “Mucus-Covered Jellyfish Hint at Dangers of Deep-Sea Mining.” European researchers write that while “the commercial mining of deep-sea mineral resources is becoming a rapidly approaching reality,” most of the research around how humans might impact deep-sea ecosystems “has focused on seafloor environments, paying less attention to organisms in the water column.”
The scientists set their sights on one such organism, the helmet jellyfish, selected in part because they’re sturdy (they don’t “turn into goo” when you catch them, one marine biologist not involved in the study explains) and can survive in a range that stretches from the ocean’s surface to depths of more than 13,000 feet. To simulate the effects of mining, the BBC reports the researchers collected 60 or so jellyfish from several Norwegian fjords, put them in rotating tanks, and exposed them to increasing temperatures and plumes of sediment.
The researchers could actually see one way in which the jellyfish responded: They produced excess mucus in a bid to wash themselves of the sediment, an activity that required extra energy that might otherwise go to tasks like sourcing food. Less visibly, researchers found that genes related to immunity and wound repair were activated. Study author Helena Hauss says the energy factor is a concerning one, as jellyfish would also need to consume more food to obtain that energy—but food isn’t plentiful in the deep ocean. “It could lead to starvation, it could lead to lower reproduction rates,” she says, per the Times, and that could trigger more issues for us on land, as they play a role in atmospheric carbon sequestration. (Read more discoveries stories.)
