There are seven existing species of sea turtle: green, hawksbill, flatback, leatherback, loggerhead, Kemp’s ridley, and olive ridley. Each species has its own hatching beaches and regions all over the world. Sea turtles can live up to 50 years or more, some living to see 100 years. Sea turtles do not reach reproductive maturity until they are 20-30 years old and remain active reproductively for another 10 years or so. Female sea turtles will lay between 2 and 8 clutches of eggs a season.
So where do turtles lay these eggs and how do the baby turtles survive their early days?
Where Do Female Sea Turtles Lay Eggs?
Female sea turtles always return to the beaches that they themselves hatched at to lay their own eggs. These are called natal beaches. Female sea turtles will come up to lay eggs between May and September. Sea turtles usually come out to lay eggs during the night, during high tide, and usually alone. The exception to this is the Kemp’s ridley turtles and the olive ridley turtles. These species' females return to their natal beaches by the hundreds and thousands to nest altogether. These masses are called Arribadas, which means “Arrival” in Spanish.
Sea turtles will go high above the watermark to make their nests in the soft sand. They dig deep vase-shaped nests with their back flippers and lay clutches of up to 100 eggs. They then cover their nest and disguise it before returning to the ocean. This process can take between 1 and 3 hours. Female turtles never return to protect or care for the baby turtles after they lay the eggs.
What Happens to the Sea Turtle Eggs?
Sea turtle eggs are soft-shelled eggs. They are misshapen and about the size of a ping-pong ball. Sea turtle incubation is 60 days, and it is during this time that the gender of the sea turtles is determined. In a phenomenon called temperature-dependent sex determination or TSD, the temperature of the sand is actually what will determine the sex of a sea turtle. Warmer sand tends to create more females and cooler sand creates more males.
Once incubation is over, the eggs all will hatch at once. A turtle nest full of hatching baby sea turtles looks like a pot of boiling water, earning the name “turtle boil”. Sea turtles hatch in unison so that their communal rush to the sea gives them their greatest chance at survival. Baby sea turtles follow the downward slope of the beach and the reflection of the sun, moon, or stars on the water to find their way to the ocean. The ocean creates a bright horizon and baby sea turtles use this to find their way to the water.
What Dangers Await Baby Sea Turtles?
Sea turtles hatch en masse because there are a lot of predators of the defenseless little 1.5-3-inch hatchlings. If they stay in groups, they are more likely to overwhelm any predators and thus manage to make it to the sea. Common predators include raccoons, sea birds, foxes, and ghost crabs.
Once the baby turtles make it to the ocean, they find sargassum floats to live in for the next few years of their life. Sargassum is a brown seaweed that floats in island-like masses over the ocean. These floating habitats are home to many small crustaceans, fish, and plants that the baby sea turtles will eat over the next few years. The seaweed will hide them while they grow over the next few years until they are ready to leave.
Female sea turtles will grow and return to these beaches to lay their own eggs one day. Male turtles on the other hand will remain out to sea for the remainder of their lives. The survival rate is slim for sea turtles, however. Only an estimated 1 out of 1,000 will make it to adulthood due to predators, pollution, the destruction of their habitats, and poaching.
More About Sea Turtles
What Do They Eat?
Sea turtles’ diet depends on their species. Green sea turtles almost exclusively feed on sea grasses. Loggerhead sea turtles eat hard-shelled crustaceans like crabs and lobsters. Hawksbill sea turtles have powerful beaks that can cut through coral sea sponges, mollusks, and anemones. Leatherback sea turtles eat jellyfish.
How Long Can a Sea Turtle Hold Its Breath?
A sea turtle can hold its breath for several hours. The more active it is the more quickly it will deplete its oxygen supply and the more frequently it will need to resurface. A resting or sleeping sea turtle, however, can hold its breath for 4 to 7 hours. Some sea turtles can even hibernate for months in the winter.
How Big Do Sea Turtles Get?
Sea turtles' size depends on their species. Leatherback sea turtles grow to be the biggest, averaging a six-foot-long carapace (or shell). The largest modern sea turtle ever measured was nine feet long and weighed over a ton. The Archelon was a species of sea turtle from millions of years ago that is now extinct. The largest specimen yet documented was 15 feet long and probably weighed over 3 tons.
Sea turtles are majestic creatures that travel the oceans for years and years. However, nearly all seven species are endangered with three of the seven being critically endangered. Its natural predators include tiger sharks and killer whales, but mostly sea turtles are endangered by humans through pollution, poaching, and even accidental capture. Take time to learn how you can contribute to the safety and protection of these gentle creatures and their habitats so they can continue living peacefully in Earth’s oceans.