Biology of the sea turtles

First steps of freshly hatched Ivorian leatherback sea turtle

There are only seven species of sea turtles worldwide. Sea turtles are phylogenetically very ancient reptiles that went from land to sea. What remains is the function of the land on which the eggs are laid, which are incubated by the sun in 27-29 ° warm sand. It takes about two months until the young hatch. Most sea turtles migrate very far across the globe, and it is still an unsolved mystery how they do it, and "arrange" for mating simultaneously at certain locations. The mating takes place in shallow water. Only the females go ashore. Spawning takes place in poor moon nights and only takes a few hours. The young hatch usually at night. They swim swiftly out into the open sea in order to escape the numerous natural predators on the beach and in the shallow waters. Natural predators of the young turtles are jackals, lizards, birds, crabs and fish. It is unknown to what places the young swim and how they live in the open sea is hardly known. The adult turtles specialize in different food resources. Green turtles are predominantly vegetable consumer, the ridley eats crabs and therefore is also growing very fast, the turtle preferred sponges. Most impressive is the largest sea turtle, which reaches up to a ton weight: the leatherback turtle. This unique animal floating around freely in the open ocean and feeds on jellyfish. The maximum diving depth up to 1000 meters have been identified as maximum dive time 70 minutes. Many details from the life of the fascinating sea turtles are still unexplored.

The sea turtles from Côte d´Ivoire

Olive ridley sea turtle in Grand Béréby

One can imagine, that that formerly almost everywhere at the coast of Côte d'Ivoire sea turtles have laid eggs, because of the geographical situation with over 500 km of coastline parallel to the equator. Giving evidence individual spawning sites in Abidjan still exist (J. Gomez, evidenced by photos). Also, substantial evidence exists that eggs are laid throughout the southwest of the country, approximately between San Pedro (pers. observation of successful reproduction in 2015 by O. Grell) and the border to Liberia. A systematic survey of marine turtles in Côte d'Ivoire is currently carried out by Alexandre Dah, University of Cocody in Abidjan. Thus, four types of sea turtles are detected with reproduction for Côte d'Ivoire. The population sizes are very different and vary from year to year. The vast majority of sea turtles lay their eggs in the area between Grand Bereby and Tabou. In this mentioned stretch of coastline following sea turtle species are found and numbers of nests per year: olive ridley sea turtle, Lepidochelys olivacea with about 1,000 nests, green turtle, Chelonia mydas with about 150 nests, Leatherback Turtle, Dermochelys coriacea with (fluctuating) up to 300 nests and the Hawksbill Turtle, Eretmochelys imbricata with individual specimens, including occupied reproduction detection. Leather and green turtle, both of which are under threat worldwide as severely threatened by extinction (IUCN). In the southwest of Côte d'Ivoire, consequently, in 2015 we can still expect viable populations of worldwide endangered sea turtles.

The threat of the sea turtles

Slaughtered sea turtle at the beach, Grand Béréby
Killed leatherback sea turtle, Grand Béréby
Eggs for sale

Most populations of sea turtles are critically endangered (IUCN). The decrease causes are primarily the loss of reproductive beaches through more intensive use by humans and direct pressure, particularly, the consumption of eggs. In Côte d'Ivoire this worldwide situation is reflected typically. The increasing population and use of coastal permits hardly a successful reproduction. Where still a remaining population exist, the eggs are dug up and eaten. The catch of sea turtles is officially prohibited by national laws, however, controls or conservation areas do not exist, so the extinction of sea turtles can be expected in Côte d'Ivoire in the near future. The protection project, founded in 2012 in Grand Bereby is the first and only initiative to obtain the precious biodiversity on the coast of Côte d'Ivoire.