Jellyfish shift ocean food webs by feeding bacteria with mucus and excrement

Despite its name, the Gulf of Mexico’s Dead Zone is full with life. This region stretches over 22,000 square kilometres, an area the size of Israel. Its waters are choked by a combination of fertiliser, sewage and industrial run-offs, flowing down from the businesses that line the Mississippi. These pollutants feed large blooms of algae that ultimately rob the water of oxygen, depriving it of the ability to support fish and other typical residents. Instead, the Dead Zone has become the dominion of jellyfish. Jellyfish congregate here in their thousands. Locals like moon jellies and sea nettles are joined by foreign travellers like the Australian spotted jellyfish. These gelatinous swarms stretch for miles, covering the ocean in a web of pulsating umbrellas and stinging tentacles. At their densest, you could scoop up a hundred jellies within a single cubic metre of water. They shut down beaches, fisheries, industries and ecosystems. ...