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Sea Turtle Nesting |
| By: LeRoy French Undersea Adventures 13 March 2009 |
;)
I know it’s a little early to be talking about turtles nesting on our
beaches but here in the Caribbean it can start as early as the end of
March.
What this means basically is that all residents should be on the lookout for turtles making nests on our beaches during this time. As all species of turtles are protected we must keep all types of vehicles, construction and heavy traffic off our beaches from March through October so we do not disturb these nests. To know more about how the nests are created, I will explain. ;)
Mother turtles come ashore usually at night and dig a hole in the
sand with their flippers and lay between 100 - 150 eggs at one
time. During this season a single female lays mutiple nests, usually
between 3 - 8. After a 45 - 70 day gestation period, hatchlings
emerge from the nest under the cover of darkness and follow the
moon reflecting off the ocean.
There are seven living species of sea turtles: flatback, green sea turtle, hawksbill, leatherback, Ridley, loggerhead and olive ridley. The hawksbill and green turtle are common in St. Maarten waters along with the occasional leatherback. These animals spend most of their lives underwater but must come to the surface to breathe air for oxygen. With a rapid exhalation and inhalation they are able to fill their lungs quickly. Their lungs permit a rapid exchange of oxygen which prevents gasses from being trapped during deep dives. ;)
During a normal dive a green turtle will submerge for about 4 - 5
minutes and surface for 1 - 3. The life expectancy of most sea turtles
is about 80 years and they are very sensitive to the Earth’s
magnetic field.
Having said that it is interesting to note that after about 30 years of maturing a female will return to land to nest at night, usually on the same beach from which it was born. Sea turtles also nest in the daytime on occasion, but the green turtle only nests at night. Generally sea turtles use the same methods for making a nest. They use their back flippers to dig a round hole about 40/50 centimeters deep. The female then deposits her soft shell eggs. She then fills the hole with loose sand and then smooths over the top so it can’t be easily detected by predators. This process takes about 30 minutes to an hour. Now what I find interesting is that the temperature of the sand determines the gender of the hatchling. Darker sands maintain higher temperatures, meaning incubation time is shortened increasing the frequency of female hatchlings. ;)
Incubation takes about two months and at that point hatchlings tear
their way out of the shell using their beak, emerge from the sand and
head for the ocean. Only .01% will make it!
If you see a turtle nesting on a beach please do not disturb it. Do not shine a light on it as the turtle will follow the light. A red light is a safe light to use as turtles cannot see red. DO NOT USE A WHITE LIGHT!! Remember I mentioned early in this article that sea turtles follow the reflection from the moon shining off the ocean. This is how they know which direction to travel in. And now some startling statistics: In the Caribbean the Green turtle population has declined since the 17th century from 91 million to 300,000 today, and the Hawksbill from 11 million to less than 30,000. Now you see why they are protected. In summary if you come across a turtle nest, do not disturb it. Mark the area and call one of our many Foundations here in St. Maarten. If you see someone digging, building or driving on a beach make it known that they could be destroying a nesting area. I will be reminding the public over the next few months about this important act of nature and how it needs to be protected. |
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