Las weekend I was very impressed with the number of turtle nests in the Mexican Caribbean this year. On a beach which I recall barely received 20 nests all season several years ago, there are already more than 50 nests. And summer is just getting started.
In recognition of what could be a very very good season, I decided to share with you the Sea Turtle chapter from my book “What did I see?”, in weekly installments, over the next month. (I would like to note that its emphasis is on the Mexican Caribbean, and apologize to other regions of the country. I hope the Pacific and Gulf coasts are also having a record season.)
Unlike other turtles, sea turtles cannot retract their head into their shell, which is lighter and more streamlined (flatter) than those of freshwater turtles. They have flippers instead of feet, which allow them to swim at speeds of up to 55 km/h. Like all aquatic reptiles, they must surface to breathe air.
The reefs, seagrass beds and nesting beaches of the Mexican Caribbean offer us unique opportunities to witness these endangered animals in their natural habitat. Mexico is home to six of the seven existing species of sea turtle, four of which visit this coast.
Though some turtles can be found year round in the bays and reefs, nesting season is during the summer months, roughly from May to October. Loggerheads are first to arrive, followed about a month later by Greens. Though Hawksbills feed in the reefs of the Eastern(or Caribbean) coast of the Yucatan Peninsula, they prefer to nest on the Northern (or Gulf of Mexico) side of the Peninsula. Visits by Leatherbacks are extremely rare, but a few sightings are reported every year.
As recently as 50 years ago, sea turtles would come upon the beaches of the Mexican Caribbean to sun themselves. However,as their numbers have plummeted and beaches have become tourist attractions, this behavior has disappeared. Only females come ashore, and only at night to lay their eggs. Each nest can have between 80-200 eggs, and females may lay more than one nest per season. Females do not care for the nest, and return to the sea immediately after laying their eggs. In fact,if a nice, dark & quiet spot cannot be found in which to dig the nest, the eggs may be dumped at sea.
Incubation lasts around 2 months, after which the hatchlings emerge from the eggs and instinctively head for the sea, where many predators await them. Bright lights can confuse hatchlings and send them in the opposite direction towards buildings and roads, so it is important that nesting beaches be kept dark. It is estimated that only 1 in 100 survives their first year, and that perhaps only about 1 in every 1,000 make it to adulthood. As adults they are remarkably well adapted to their environment and have only two predators: sharks and humans.
Sea turtles have been around for 150 million years, and were around when dinosaurs ruled the earth, but now all sea turtle species are either Endangered or Critically Endangered. Threats include poaching, loss of nesting grounds, accidental by-catch by commercial fisheries, marine garbage (which they can mistake for food and choke on), and a mysterious illness (fibropapilloma) that has been linked to pollution.
You can help them survive by keeping the beaches clean, and turning off any lights that face the beach during nesting season (May – October). If you encounter a nesting turtle, please do not approach it or shine lights on it.
It is illegal to kill, capture, or harass sea turtles, or to deal in any sea turtle product.