2. Sea turtles are related to land turtles.
3. Sea turtles are adapted for swimming.
5. Sea turtles lay eggs on land.
All sea turtles (and all turtles) lay eggs, so they are oviparous. Sea turtles hatch from eggs on shore, and then spend several years out at sea. It may take 5 to 35 years for them to become sexually mature, depending on the species. At this point, males and females migrate to breeding grounds, which are often near nesting areas. Males and females mate offshore, and females travel to nesting areas to lay their eggs.
Amazingly, females return to the same beach where they were born to lay their eggs, even though it may be 30 years later and the appearance of the beach may have greatly changed. The female crawls up on the beach, digs a pit for her body (which can be more than a foot deep for some species) with her flippers, and then digs a nest for the eggs with her hind flippers. She then lays her eggs, covers her nest with the hind flippers and packs the sand down, then heads for the ocean. A turtle may lay several clutches of eggs during the nesting season.
6. A sea turtle's gender is determined by the temperature of the nest.
Sea turtle eggs need to incubate for 45 to 70 days before they hatch. The length of incubation time is affected by the temperature of the sand in which the eggs are laid. Eggs hatch more quickly if the temperature of the nest is warm. So if eggs are laid in a sunny spot and there is limited rain, they may hatch in 45 days, while eggs laid in a shady spot or in cooler weather will take longer to hatch.
Temperature also determines the gender (sex) of the hatchling. Cooler temperatures favor the development of more males, and warmer temperatures favor the development of more females (think of the potential implications of global warming!). Interestingly, even the position of the egg in the nest could affect the gender of the hatchling. The center of the nest is warmer, therefore eggs in the center are more likely to hatch females, while eggs on the outside are more likely to hatch males. As noted by James R. Spotila in Sea Turtles: A Complete Guide to Their Biology, Behavior and Conservation, "Indeed, which way an egg bounces into the nest might determine its sex." (p.15)
7. Sea turtles can migrate extreme distances.
8. Sea turtles live a long time.It takes most sea turtle species a long time to mature. Consequently, these animals live a long time. Estimates for the lifespan of sea turtles is 70-80 years.
9. The first marine turtles lived about 220 million years ago.Sea turtles have been around for a long time in evolutionary history. The first turtle-like animals are thought to have lived about 260 million years ago, and odontochelys, the first marine turtle, is thought to have lived about 220 million years ago. Unlike modern turtles, odontochelys had teeth. Click for more about leatherback turtle evolution and evolution of turtles and marine turtles.
10. Sea turtles are endangered.
You can help by:
- Supporting sea turtle research and conservation organizations and projects through volunteering or donating funds.
- Supporting measures to protect nesting habitats.
- Choosing seafood that is caught without impacting turtles (e.g., in areas where turtle excluder devices are used, or where bycatch is minimal).
- Not purchasing sea turtle products, including meat, eggs, oil, or tortoiseshell.
- Watching out for sea turtles if you are out on a boat in sea turtle habitat.
- Reducing marine debris. This includes always disposing of your trash properly, using fewer disposable items and plastics, buying locally and purchasing items with less packaging.
- Reducing your carbon footprint by using less energy.