Costa Rica is a tropical country of 51,100 km2 terrestrial, but with a marine extension of 589,163 km2, with many volcanoes, mountains, rivers and beaches on both coasts of great natural beauty; it has approximately 5% of the world’s biodiversity. Costa Rica has a tropical climate with two seasons: Dry, from December to April; and Rain, the rest of the year.
For these reasons, year after year thousands of people from different countries of the world, choose Costa Rica as a tourist destination.
Where is the sea turtle Project?
Our sea turtles research and conservation projects are located on the north side of Costa Rica, in the province of Guanacaste, canton Santa Cruz, district of Cabo Velas, close to the community of Matapalo. The beaches Nombre de Jesús, Zapotillal, Real and Honda are located approximately 12 kilometers north of Las Baulas National Marine Park.
The Beaches are adjacent and separated by rocky cliffs with abundant vegetation, in the canton of Santa Cruz and province of Guanacaste, Costa Rica.
Figure. Location of sea turtle nesting beaches under the Kuemar monitoring program in Guanacaste, Costa Rica.
Sea turtles of the world
Sea turtles are reptiles that have lived on Earth for more than 100 million years. They evolved from freshwater turtles. Through their long history they have survived drastic changes in the environment, the same ones that caused the disappearance of the dinosaurs. They have physiological and anatomical adaptations to live in a marine and terrestrial environment. Sea turtles are cold-blooded animals and use sunlight to warm their bodies because they are not able to maintain a constant body temperature. Sea turtles breathe through the lungs, emerging to the surface from time to time to breathe. They have a shell: dorsal and ventral, which both serve as protection for internal organs. The Baula (Dermochelys coriacea) sea turtle is distinguished by its soft shell, covered by a thick layer of leather-like skin. Turtles lack teeth in their jaws, they have primitive ears, but an excellent sense of smell and good vision under water.
Their fins are long (the length of the shell) and they have one or two reduced claws on the front fins, with the exception of the leatherback turtle, which lacks claws.
The tail of the male is longer than that of the female, and is used to hold the female at the time of mating.
They dive to great depths, mainly the Baula turtle, with a maximum recorded depth of up to 1300 meters (Eckert 1989). During the dive, sea turtles lower their heart rate and their brain works with reduced oxygen concentrations.
Species that nest on the study beaches:
Green/Black Turtle (Chelonia mydas agassizii): This is the species that nests in greater quantities.
The Black Turtle’s carapace length can reach 120 cm and weigh up to a total of 230kg. This species inhabits shallow waters around coral reefs, estuaries and bays. Its diet consists of seagrass and marine algae.
Olive Ridley (Lepidochelys olivacea):
The average carapace length is 66cm and total weight fluctuates from 35-50kg. They live in tropical and temperate waters. The Olive Ridley mainly feeds on benthic crustaceans, such as: crabs, snails, tunicates, sessile, shrimp and algae.
Leatherback Turtle (Dermochelys coriacea):
The curved carapace length can reach 180cm and can weigh up to a total of 500kg. They are associated with pelagic environments and deep waters. The Leatherback feeds on marine invertebrates, but its diet mainly comprises of jellyfish.
Hawksbill Turtle (Eretmochelys imbricata):
The adults are between 65 and 95 cm in length and weigh about 60 kg. Their shell consists of overlapping bony plates of dark brown, amber, yellow or coffee colour.
It is common to see them in coral reefs; their main diet is made up of sponges; their jaw has a “peak” shape, which allows them to reach
the food located between rocks and corals.
This species of turtle is captured mainly for its shell, since it is used to make jewellery which has a high commercial value. It is the most tropical of all sea turtles and is distributed in the Caribbean and the Pacific.
Their nesting on these beaches is not very frequent.