The Leatherback is the largest of all sea turtles and weighing as much as 2,000 pounds. It is seen only in the open ocean. Yes, all sea turtles are listed as endangered or threatened under the federal Endangered Species Act. Following decades of over-exploitation, the population of Green sea turtles in Hawaii has shown some signs of recovery since receiving protection in 1978. There are now an estimated 1400 adult females.
Hawksbill turtles are critically endangered with very few remaining.
Turtle populations are threatened by hunting, habitat destruction, stealing of eggs, entanglement in nets, and ingestion of marine debris. Their main predators as adults are sharks and humans. Yes, like all reptiles, they breathe air. When they are active, sea turtles surface to breathe every few minutes, but when they are resting, they can remain underwater for over 2 hours. The tail of the male turtles is much longer than that of the female.