The marine turtles have a surprising and still relatively unknown way of life. Spending all their life in the sea, except for the grown-up adult females which appear briefly to come to lay, the turtles are capable of crossing oceans and can wait 30 years before reproducing.
In French Polynesia, the turtles ( honu ) is crowned (tabu ) since the origin of time.
Although protected Internationally by the agreement of Washington and locally by the local regulation, the turtle is still threatened of extinction if we are not careful there.
We can observe 4 to 5 species of turtles in French Polynesia but mostly two: the green turtle and the imbricated turtle.
The most frequently met turtle in the lagoon of Bora Bora as well as in the Le Méridien interior lagoon, is the green turtle or Chelonia mydas. Its name is due to the green color of its fat. The green turtle measures between 80 and 120 cms for approximately 230 kg. During its first year of life, the green turtle lives near the surface of the ocean where it feeds on numerous plankton: jellyfishe, mollusks ... This zoophage diet corresponds to the needs of fast growth of a young animal. After this time the green turtle switch more and more on a vegetarian diet consisting mostly on algue that is coloring is fat.
The second common specie is the hawksbill turtle (Eretmochelys imbricita) which measures less than 90 cms and weighs on average 50 kg. We recognize it by the crichu beak (parrot like) and the beauty of the scales. It swims near coasts to feed on crabs, fishes, sponges, shells, etc. No layings observed untill this day in Bora Bora, in spite of their rather important presence.
Reproduction and layings of eggs
According to the scientific studies of other continents, during coupling in sea, the male hangs on to the female's carapace. However, the coupling does not seem to be made in the Bora Bora's waters as nobody was until then able to observe it. The turtles lay on beaches all year round but we notice that in Bora Bora the most convenient periods remain from November till January. Green sea turtles are sexually mature around 20/30 years old. They mate generally every 3 years and mothers use to come back where they were born.
The turtles cross the cliff, the lagoon, exceed the beach and the height of the platier and go to the bottom of the plants of the cost like Miki Miki. Females begin their trip at about 6:00 pm to finish their layings one hour and a half later. Before laying, the female turtles look for the place must appropriate to lay their eggs. Their choice being made, females fit out a wide physical cavity by means of both fins.
In thirty minutes, the layings are finished. However, they can lease at any time because of an abnormal noise, an excessive luminosity ...
The turtle fills the nest of wet sand which she compresses slowly with its hind legs. It buries then eggs in 70 cms (30") under the surface. Then the hind fins dig a hole in the form of bottle where the eggs will be layed. In French Polynesia nests observed on the motu contain about 60 in 70 eggs. In a season, a female comes to put down its eggs on average three times in more or less ten days of interval according to the observations made in Le Méridien Bora Bora. What was noticed is that the places of laying are separated from each other only by approximately 100 metres.
Exit from the nest
In the sand, the eggs will hatch after approximately 60 days. The temperature of the nest seems to play a very important role. It conditions not only the duration of incubation but also the distribution of the sexes through the small turtles. The newborn stay some days in the nest; by movements they displace under them the sand which surmounts the nest and approach the surface. The place of exit will be determined by the temperature because the newly born turtles require a cool environment. We can then admire the turtles swimming towards the lagoon, passing above the cliff and going away where they are carried by the sea. They will feed with zooplancton (fishe larvas, shellfishe, cephalopods) to begin their growth.