Sea turtles have hard shells (called carapaces) that help protect them, but they still have predators. They are also more vulnerable than land turtles because unlike land turtles, sea turtles are unable to retract their heads or flippers into their shell.
Predators of Sea Turtle Eggs and Hatchlings
There are some predators of sea turtles as adults, but these marine reptiles are most vulnerable when in the egg and as hatchlings (small turtles recently emerged from the egg).
Predators of eggs and hatchlings include dogs, cats, raccoons, boars, and ghost crabs. These animals may dig up a sea turtle nest to get to the eggs, even if the nest is 2 feet below the surface of the sand. As hatchlings start to emerge, there is a scent of egg that still is on their bodies, plus the smell of wet sand. These scents can be detected by predators even from a distance.
Once hatchlings emerge from the egg, they need to get to the water. At this point, birds such as gulls and night herons can become an additional threat. According to the Sea Turtle Conservancy, as few as one in 10,000 sea turtle eggs reach adulthood.
Olive ridley turtles nest in huge groups called arribadas. These arribadas can attract animals such as vultures, coatis, coyotes, jaguars and raccoons, who may gather near the beach even before the arribada begins. These animals dig up nests and eat eggs, and prey on nesting adults.
Predators of Adult Sea Turtles
Once turtles make their way to the water, both juveniles and adults can be prey for other ocean animals, including sharks (especially tiger sharks), orcas (killer whales), and large fish, such as grouper.
Sea turtles are built for life in the water, not on land. So adults can also be vulnerable to predators such as dogs and coyotes when they go up upon beaches to nest.
Sea Turtles and Humans
If turtles survive their natural predators, they still face threats from humans. Harvest for meat, oil, scutes, skin and eggs decimated turtle populations in some areas. Sea turtles face development on their natural nesting beaches, which means they have to contend with such things as artificial light, and loss of habitat and nesting sites due to construction and beach erosion. Hatchlings find their way to the sea using natural light, the slope of the shore, and the sounds of the ocean, and coastal development can interrupt these cues and make hatchlings crawl in the wrong direction.
Turtles may also be caught as bycatch in fishing gear, which was such a problem that turtle excluder devices were developed, although their use is not always enforced. You can find more information about fisheries regulations and recovery plans related to turtles at this NOAA web site.
Pollution such as marine debris is another threat. Discarded balloons, plastic bags, wrappers, discarded fishing line and other trash may be mistaken by a turtle for food and be accidently ingested, or the turtle may become entangled. Turtles may also be struck by boats.
How to Help Sea Turtles
A sea turtle's life may be fraught with danger. How can you help?
If you live in a coastal area:
- Don't feel wildlife - you may attract turtle predators.
- Don't let your dog or cat run loose.
- Watch for sea turtles when boating.
- Do not disturb or shine lights near nesting sea turtles.
- Turn off outside, ocean-facing lights during sea turtle nesting season.
- Pick up litter on the beach.
Wherever you live:
- Dispose of trash responsibly, and keep a lid on your trash when it's outside. Trash even far from the ocean can make it's way there eventually.
- Never release balloons - always pop them and dispose of them in the trash . Use balloon alternatives whenever possible during your celebrations.
- If you eat seafood, research what you eat and eat seafood that is caught without threatening turtles.
- Support sea turtle conservation/rehabilitation organizations, even international ones. Sea turtles are highly migratory, so recovery of turtle populations depends on protection in all their habitats.
References and Further Information:
- Network for Endangered Sea Turtles. Accessed May 30, 2013.
- Sea Turtle Conservancy. Sea Turtle Threats: Invasive Species Predation. Accessed May 30, 2013.
- Spotila, J. R. 2004. Sea Turtles: A Complete Guide to Their Biology, Behavior, and Conservation. The Johns Hopkins University Press: Baltimore and London.
- The Georgia Sea Turtle Center. Threats to Sea Turtles. Accessed May 30, 2013.