Wednesday 6 March 2013

About Sea Turtles and the Conservation Project on Mano Juan, Saona Island

There are three different species of sea turtle that nest on the island of Saona, Dominican Republic. The Leatherback, Green and Hawksbill. The Hawksbill sea turtle is the species that occurs here the most so this project revolves mostly about them.


Saona Island, Dominican Republic
What happens in nature is the female will come onto the beach and will start digging to build a nest. She then lays around 140 eggs of which most are fertile and a few are not. The fertile eggs are laid first and then the layer of unfertilized eggs on top to provide protection. The temperature of the nest determines the sex of the baby sea turtle. If the mid-temperature of the nest is 29.2 degrees Celsius there will be a 1:1 ratio male to female. Cooler temperatures (deeper in the nest) will produce males. Warmer temperatures (closer to the surface) will produce females.

These eggs will hatch after about 2 months. The hatchlings will stay in the nest for 3 days. On the third night when and only if the sky is clear (no cloud cover) the baby sea turtles will race to the beach. When there is cloud cover they will stay in the nest waiting for the next clear night. Why? The females make an imprint of the stars to be able to come back 25 years later to the same coast where they were born to lay their own eggs. How exactly this works is still a mystery but what we do know is that they find their way back using the stars as well as the magnetic field of the Earth. Pretty impressive!



1-day-old Hawksbill Sea Turtle
The Hawksbill sea turtle has a lot of predators, crabs, frigate birds and various mammals will eat the baby sea turtles walking towards the sea, in the water they are the prey for many fish and the adults will sometimes be eaten by sharks.

There are also many anthropogenic threats. The nests often get stolen because the eggs can be sold for a lot of money. The reason why is because there are people who believe that these eggs are an aphrodisiac. It is the same story like the Rhino horn from Africa that makes its way to China. Scientifically there is no basis for thinking that it might actually be an aphrodisiac but it is all about what people believe themselves.

These turtles are also poached for their shell. Every sea turtle species in the world is endangered or threatened in some way and so every sea turtle species is protected and there is an expensive fine involved if you are caught with sea turtle shell in your possession.

Fishing nets can also entrap the turtles. The sea turtle needs to come up for air every 12 minutes, if it is stuck in a net it will drown.



Information banner at the Sea Turtle Conservation Project


At the current moment the Hawksbill Sea Turtle is listed as critically endangered, this is very close to extinction. It takes the female 25 years to reach sexual maturity and only 5% of the baby sea turtles survive to adulthood.

There are various people involved in the sea turtle project. Seavis Tours sponsors the project. Yolanda Leon is the senior scientist. and our HERO Nergo is responsible for the operational side of things.

Negro goes and checks all the nests along the 25km of coast every night. If he comes across a new nest he gathers all the data he can including GPS coordinates. The most important thing he does is eliminate the tracks of the female sea turtle that came to lay her eggs. In that way the nests stay “hidden” and are unlikely to be spotted by poachers.

If a nest is laid in a high risk zone (where poachers often come to shore or where there are tourists) he takes the nest out carefully and incubates the eggs in cooler boxes. Every time a nest is taken out all possible information about the eggs is noted to monitor the condition and amount of eggs. A nest is only ever taken out of the wild in order to prevent it from getting stolen or stepped on by tourists.

The eggs at the project will hatch after 2 months, just like in the wild and the baby sea turtles are kept at the project in their cooler box nest for 3 days, on the third night, if the sky is clear, Negro takes the nest to the exact place where the eggs were laid and sets the little ones free. They have to walk to the water themselves.

This project has been running for 6 years and we are very proud to be able to say that there are now 30% more nests than when the project started!



Kids from a tour group holding baby Hawksbill Sea Turtles


Many tourist groups visit the project which is a great opportunity for education and awareness.


Tour guide (Kirsten) explaining all about sea turtle conservation

1 comment:

  1. I have read your blog that you mentioned regardig Saona Island, it is the no. 1 Tour Destination in the Dominican Republic.

    ReplyDelete