Tuesday 30 July 2013

Update

We have many nests at the Sea Turtle Conservation Project!
We have new hatchlings almost every other day.
 It will be interesting to see what the data says after this breeding season, we think it will be a positive result!

Wednesday 29 May 2013

Hatchling to Juvenile and Beyond

What happens when a baby sea turtle enters the water at 3 days old? The answer is we don't really know. Baby sea turtles are difficult to track because today's tracking devises are too big to put on hatchlings.

Satelite tracker on adult sea turtle.


What we do know:
The baby sea turtle needs to get to the water as quickly as possible to avoid getting eaten by predators (birds, small mammals, crabs).
Once the baby sea turtle is in the water it needs to get away from the shallow shore waters where predators such as sharks and big fish are ready for an easy meal.
The baby sea turtle needs to find food.

Natural predators of Sea Turtles.

So the baby sea turtles part take in what is called a swimming frenzie where they try to get to the deeper waters as soon as possible. They often get sweeped up by sea currents or travel by a type of sea weed (Sargassum) that floats on these currents. If they can find a patch of floating vegetation they are protected from predators and have a source of food. These currents take them for houndreds (sometimes even thousands) of kilometers. They stay in these currents for years until they have reached the sub-adult stage.

Juvenile Hawksbill Sea Turtles.

Juvenile Hawksbill Sea Turtle.


In their sub-adult stage they come back to the shallow shore waters to feed on sponges, anemones and squid that live in the coral. The Hawksbill Sea Turtle reaches sexual maturity at around 10-25 years of age. This depends on many factors such as food availability and population size. They live up to 50 years old.

Hawksbill Sea Turtle in its natural habitat.
Adult Hawksbill Sea Turtle.


We have 4 nests at the Sea Turtle Conservation Project, Mano Juan, Saona Island and are awaiting our first hatchlings of the season.

Adult Hawksbill Sea Turtle at coral reef. 


Next up: Courtship and mating

Thursday 18 April 2013

The First Few Days of the Life of a Baby Sea Turtle


The temperature of the sand is the main factor influencing the development of the baby sea turtle in its egg. This means that incubation times vary. The higher the temperature of the sand where the eggs are incubated the quicker the baby develops. The cooler the temperature of the sand where the eggs are incubated the slower the baby develops.

When the baby sea turtle is ready to emerge from its egg it uses its temporary tooth (caruncle) to pierce a hole in the egg shell. The baby crawls out of its egg and finds itself in a nest underground.

Sea Turtle Nest in the sand. (Photo by Yolanda Leon)

The baby sea turtles make a collective effort to the surface where they open their eyes the the world for the first time. They will stay together in the open nest for three days. On the third night they start their journey to the big blue. 

Newly hatched baby sea turtles in the nest. (Photo by Tony Tosto)
Baby sea turtles just after hatching. (Photo by Tony Tosto)
This journey is a dangerous one as anything from sea birds to crabs as well as Turkey Vultures are waiting for an easy meal. The baby sea turtles are also hindered by shells and sticks on the sand, for a baby sea turtle these obstacles can look like mountains.

Crab, predator. (Photo by Tony Tosto)

Frigate Bird, predator. (Photo by Tony Tosto)

Turkey Vulture, predator. (Photo by Tony Tosto)

Only 5% of the baby sea turtles will survive to mate and have their own offspring. This is a serious case of survival of the fittest with a little bit of luck needed on the side. Many of the baby sea turtles will be eaten by predators on the beach. After they have made it to the water they will be faced with many other dangers such as predatory fish, the chance of getting hit by boats and they are in danger of getting tangled up in fishing nets of plastic.

The ones that do survive will be cruising on sea currents into the deep waters to escape the dangerous shore water predators. This is where the lonesome journey from hatchling to juvenile begins.

Baby Sea Turtles walking to the ocean. (Photo by Yolanda Leon)
Next up: Hatchling to Juvenile and Beyond  

Wednesday 27 March 2013

Hawksbill Turtle Nesting

Hi Sea Turtle lovers,

We have no nests at the Sea Turtle Conservation Project Mano Juan, Saona right now and that is because it is not breeding season.

I was looking up on when the actual breeding season is for the Hawksbill Sea Turtle and found that all the sources say something different. This might mean that the breeding season for these creatures depends on their location.

We see our sea turtles arriving to nest in May and lately we have seen that the breeding season is becoming longer with the last females coming to nest as late as December.
A map of Saona Island and where the nests are situated.

The female Hawksbill Sea Turtle comes to lay eggs around 4 times in a season. She will emerge from the water and slowly crawl on the beach to find a perfect spot for her precious eggs. Once a suited spot is found she will dig a hole in the sand using her flippers. The nest is usually in the shape of a tear drop and is slightly tilted.
Female Hawksbill Sea Turtle in the process of laying her eggs.
Eggs come out in 2's or 3's. She will typically lay around 120 eggs. These eggs are not hard like chicken eggs but are flexible so they do not break when they fall onto the sand. Once all the eggs are in the nest she will cover the eggs with sand using her rear flippers. When she feels the nest is covered she will crawl back to the ocean never to tend to her eggs again.

Egg-laying
The eggs will hatch after about 60 days, depending on the temperature the babies might emerge later or earlier. The temperature of the nest determines the sex of the baby with temperatures warmer than 29.2 degrees Celsius producing females and colder producing males.

Sea Turtle nest in the sand.
The baby sea turtle emerges from its egg by using an "egg-tooth" called the "caruncle". They will loose this "tooth" shortly after they have emerged.

And so the life of a baby sea turtle begins.

Baby Sea Turtles making the dangerous journey to the ocean.
The Sea Turtle Conservation Project on Mano Juan, Saona keeps track of all the nests using a GPS. If a nest is situated in a high risk zone where it might get stepped on or stolen by poachers the Sea Turtle Conservation Project will step in and carefully remove the nest. The eggs are then incubated into cooler boxes and taken to the project until they hatch.

Yolanda and Negro of the Sea Turtle Conservation Project Mano Juan, Saona Island carefully taking out a nest that was at  risk of being discovered by poachers.

Negro and the local kids at the Sea Turtle Conservation Project Mano Juan, Saona Island with a newly hatched nest.

Baby Sea Turtles released after hatching at the project.

Next up: The First Few Days of a Baby Hawksbill Sea Turtle!!!

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