The mysteries of the deep ocean are being revealed, bit by bit, with the help of some unconventional research assistants: large sea animals. Scientists are attaching high-tech tags and sensors to the fins, flippers, and tails of whale sharks, seals, tuna, swordfish, rays, and other creatures. The animals are gathering useful data.
It’s difficult for researchers to study waters deeper than about 1,600 feet below the surface, in the mesopelagic, or twilight, zone. (This zone ranges from about 650 to 3,300 feet below the surface.) The water pressure is so intense there that it isn’t safe for people, and sunlight barely reaches it. Deeper than that, in the bathypelagic, or midnight, zone (about 3,300 to 13,100 feet down), there is no sunlight at all.
Scientists have known for many years…
