"When three scientists descended over a thousand feet underwater in an exploration vessel off the coast of Panama, they expected to see many kinds of life. They'd chosen to explore the Hannibal Seamount, a flat-topped undersea mountain that's the ocean equivalent of a tropical jungle, rich with a diversity of animals and plants found nowhere else. Their submersible, the Deep Rover 2, has the look of a giant, transparent bubble; with the help of spotlights, they could peer out from every angle. But as they approached the northwest flank of the seamount, they saw something inexplicable on the ocean floor."
"It looked like an underwater dust storm. As they got closer, the researchers realised it was an enormous swarm of crabs, kicking up sediment from the seafloor. They had never seen anything like it."