When they are active, sea turtles must swim to the ocean surface to breathe every few minutes. When they are resting, they can remain underwater for as long as 2 hours without breathing.

The green sea turtle is a medium to large brownish sea turtle with a radiating or mottled pattern of markings on the shell. The head is small in comparison to the other sea turtles and the biting edge of the lower jaw is serrated. Adult shell lengths range in size from 0.9-1.1 meters (36-43 inches) and weights average 90-137 kilograms (200-300 pounds). Primarily a tropical herbivorous species, the juveniles frequently occur in Florida waters, especially in areas abundant with sea grasses. The greatest cause of decline for green turtles has been commercial harvest for eggs and food, as well as leather and jewelry.

The hawksbill sea turtle is a small to medium sea turtle with a very attractively colored shell of thick overlapping scales. This shell is the source of "tortoise shell." Hawksbill turtles have a distinct, hawk-like beak. Adults range in size from 0.8-1.0 meters (30-36 inches) shell length and weigh 45-90 kilograms (100-200 pounds). The hawksbill turtle is a shy tropical reef dwelling species that feeds primarily on sponges. Commercial exploitation is the major cause of the continued decline of the hawksbill sea turtle. There is a continuing demand for the hawksbill's shell as well as other products including leather, oil, perfume, and cosmetics. The hawksbill shell commands high prices (currently $225/kilogram), a major factor preventing effective protection.

The leatherback is the largest sea turtle. Individuals have attained a shell length of 1.85 meters (6 feet) and weights of 637 kilograms (1,400 pounds). Unlike other species of sea turtle, the leatherback does not have scales. Instead, it is covered with a firm, rubbery skin with seven longitudinal ridges or keels. Leatherback sea turtles are a highly migratory species that nests in the tropics and ranges as far north as Canada and the northern Pacific ocean. The leatherback sea turtle feeds primarily on jellyfish. The species faces significant threats from incidental take in commercial fisheries and marine pollution, as well as from the harvest of eggs and flesh.

The Turtle Excluder Device or TED is a grid of bars with an opening either at the top or the bottom. The grid is fitted into the neck of a shrimp trawl. Small animals like shrimp slip through the bars and are caught in the bag end of the trawl. Large animals such as turtles and sharks, when caught at the mouth of the trawl, strike the grid bars and are ejected through the opening.