The twilight zone extends across all oceans on the globe. As a result, the twilight zone is one of the more poorly understood ecosystems of the Earth. The twilight zone is so mysterious, we don’t even know how many things live thereLet’s start off with what is known about the ocean’s twilight zone. “It’s been called the greatest migration on Earth,” says Annette Govindarajan, a WHOI oceanographer who also does twilight zone research. ... And attractive to predatorsThorrold got interested in the twilight zone because he was researching big predator species, like sharks, swordfish, and tuna.