Leatherback turtles have few natural predators once they mature; they are most vulnerable to predation in their early life stages. Birds, small mammals, and other opportunists dig up the nests of turtles and consume eggs. Shorebirds and crustaceans prey on the hatchings scrambling for the sea. Once they enter the water, they become prey to predatory fish and cephalopods.
Leatherbacks have slightly fewer human-related threats than other sea turtle species. Their flesh contains too much oil and fat, reducing the demand. However, human activity still endangers leatherback turtles in direct and indirect ways. Directly, a few are caught for their meat by subsistence fisheries. Nests are raided by humans in places such as Southeast Asia.[71]
Decaying plastic bag resembling jellyfish
Many human activities indirectly harm Dermochelys populations. As a pelagic species, D. coriacea is occasionally caught as bycatch. As the largest living sea turtles, turtle excluder devices can be ineffective with mature adults. In the eastern Pacific alone, a reported average of 1,500 mature females were accidentally caught annually in the 1990s.[71] Pollution, both chemical and physical, can also be fatal. Many turtles die from malabsorption and intestinal blockage following the ingestion of balloons and plastic bags which resemble their jellyfish prey.[18] Chemical pollution also has an adverse effect on Dermochelys. A high level of phthalates has been measured in their eggs' yolks.[71]