Sea turtles are ancient ocean dwellers that have lived on the earth for 150 million years, since before the time of the dinosaurs. They are large, air breathing reptiles that inhabit both tropical and subtropical seas all over the world. Sea turtles spend most of their life at sea, but females come ashore to nest and lay their eggs beneath the sand.
There are 7 species of sea turtles: Green, Kemp’s ridley, Olive ridley, Hawksbill, Leatherback, Flatback and Loggerhead. The leatherback is the only sea turtle that we would likely spot in the wild near the Bay area.
Sea Turtle Fun
Facts
- Sea turtles are deep divers and can remain active underwater for 45 minutes or more without breathing.
- They have special components in their brains that help them sense the Earth’s magnetic field and help with their migration.
- Sea turtles have special glands that excrete salt from their blood to help eliminate salt water taken in with food.
- Temperature controls hatching of turtle eggs, but also determines each hatching’s sex. Unlike humans, a sea turtle’s sex is not determined by X and Y chromosomes. A few degrees difference will determine if the hatchling is a male or a female.
Leatherbacks - the Giant Mariner- The leatherback is the largest turtle, and largest living reptile in the world! It can weigh up to 2000lbs.
- The leatherback is named for its shell (carapace) made of leathery tissue and
connective tissue (not bone)
- Leatherbacks are the most migratory and wide-ranging of sea turtles.
- They hold the turtle record for deep diving (2,417 ft/ 737m) by
a female migrating from Costa Rica to the Galapagos Islands.
- Their soft shells
may help leatherback dive deep, absorbing the intense water pressure.
*In January 2012, federal regulators designated nearly 42,000 square miles of ocean along the West Coast as critical habitat for the Pacific leatherback turtle. Read more here.
Endangered
SpeciesAll 7 species of sea turtle are either critically endangered or
threatened. Only a fraction of the
thousands of hatchlings emerging from their nests will survive to adulthood. Natural obstacles between a turtle and
survival exist, but it is the increasing threats caused by humans that are
driving them towards extinction. The population of leatherbacks has declined by
95% over just the past 25 years. Major Threats
- Poaching of turtles and turtle eggs
- Drowning in shrimp nets and being dragged by longline
hooks set by tuna and swordfish fishers
- Destruction of nesting beaches
- Pollution and plastic debris in the ocean
- Pollution
can affect the health of turtles and make them more susceptible to disease,
especially Fibropapilloma (a chronic disease which causes tumors).
- Turtles
mistake plastic bags and other garbage for jellyfish
- Climate change- warming ocean temperatures are likely to
negatively impact the food resources for sea turtles and other marine species
Photo caption (right): Photograph shows a Green Sea Turtle immediately after it was freed of a cinched plastic tie around its body. The turtle's body had grown around the plastic tie.
What can we do?*1) Reduce the amount of garbage you produce and clean up trash you see on the beach. Sea turtles can become tangled in plastic and trash both on the shore and in the water. Discarded items such as fishing lines, balloons and plastic bags may also be confused for food and eaten by sea turtles, often resulting in injury or death. 2) Reduce the amount of chemicals you use.
The chemicals you use on your lawn and in your home can actually wash into the coastal waters – killing plants and animals. It is very important to properly dispose of toxic chemicals and, even better, find alternative products such as biodegradable solutions.Reduce the amount of chemicals that you use.
Photo Caption: Close up of plastic found in digestive system of a dead sea turtle.
3) Be aware of sea turtle nesting areas and avoid nesting and hatching turtles. Sea turtles are cute, and therefore tempting to touch and observe – but flashlights and people disturb turtles when they are nesting, or trying to nest, on the beach. If you are in an area where sea turtles nest, make sure to give nesting areas plenty of space, and do not disturb females as they emerge from the ocean looking for a place to nest. Also be conscious of where nesting areas are so that you can avoid trampling the hatchlings as they head to the water.
4) Make ocean-friendly seafood choices Seafood Watch has a consumer's guide to sustainable seafood, which includes bycatch as one of its criteria for determining sustainability. Visit Seafood Watch for more information.
5) Support local and national efforts to protect sea turtles
6) Volunteer!
There are countless ways in which you can make a positive difference in the lives of sea turtles. Organize a clean-up day with your friends or join an organized Pacifica Beach Coalition cleanup to clear the beach of litter, give a presentation to your neighborhood or local school on things they can do to save sea turtles, and most importantly, talk to others about what they can do to make sure they are not putting these important creatures in danger.
* Adapted from Defenders of Wildlife
Suggested readingsVoyage of the Turtle: In pursuit of the Earth’s Last Dinosaur by Carl Safina
Sea Turtles by J.R. Spotila (2005)
Baltimore: Johns Hopkins Univ. Press (great info on trends, threats, basic biology)
Interrupted Journey:
Saving Endangered Sea Turtles by Kathryn Lasky and Christopher
G. Knight (May 9, 2006)
Singing the Turtles to Sea:
The Comcasc (Seri) art and science of reptiles. Gary Paul Nabhan, Harry W. Greene (2003).
Books for kids
Luna by J.
Cummings (2001)
Sea Turtles: Ocean
Nomads by M.M. Cerulo and J.L. Rotman (2003).
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