This blog follows on from ‘The long walk to sea’ which followed a turtle’s journey from egg to sea. This time we explore where sea turtles go after they reach the sea as a hatchling and what they do before reaching adulthood. It looks at the research and conservation methods being used to discover the life of a juvenile turtle and how we can use this knowledge to effectively protect them.
For a long time, little was known about the life of turtles between leaving the beach as a hatchling and returning to that beach to lay their own eggs. Today, scientists use satellite tagging, ocean currents and boat observations to piece together the lost years.
The first ten years of a turtle’s life is often referred to as the lost years because many people have no idea where they go or what they do. The majority of scientific research carried out on sea turtles is done at nesting beaches as it is easily accessible for scientists compared to the open ocean. This means we know lots about mother turtles and hatchlings but the stage between hatchling and adulthood is unknown. It also means that most conservation efforts for turtles are aimed at nesting beaches even though turtles spend less than 10% of their life on beaches. To fully protect sea turtles in their full geographical range, we must find out more about where they go and what they do in the water.
One conservation method that has successfully achieved this is in Costa Rica. A small metal tag was attached to female turtles nesting on beaches. Each tag has a code and a message. When the tags inevitably fall off; people that find the tags are given a small reward for returning the tag to an address. From this, researchers have learnt that a large portion of those turtles go to Nicaragua and now efforts are focused on discouraging people from killing turtles for meat in that area.
Researchers in Florida gave us some insight into where hatchlings go once they reach the water. They attached small satellite tags on 17 loggerhead sea turtles and followed their movements. This was the first data to document the benefits of surface living for juvenile sea turtles and gave us huge insights into where they go. As soon as hatchlings have made it to the water they head out to sea to avoid fish and other predators. They are often picked up by ocean currents and spend much of their time floating
This was the first data to document the benefits of surface living for juvenile sea turtles and gave us huge insights into where they go. As soon as hatchlings have made it to the water they head out to sea to avoid fish and other predators. They are often picked up by ocean currents and spend much of their time floating around at the surface in order to absorb sunlight. They may also be waiting to develop their lung capacity for diving.
Furthermore, different migration paths may affect their growth and population dynamics. Turtles in warmer waters may grow quicker and mature faster than those that hang around in colder waters. A few years later the juvenile turtles spend time feeding and growing in nearshore waters and, once they reach sexual maturity, they migrate to a new feeding ground away from their nesting beach.
Currently, scientists use satellite tags and computer mapping programs to monitor where they go when they migrate, what routes they take, and how fast they swim. We can learn where their major feeding grounds are and what major threats they face. This allows conservationists to prioritise and focus efforts on these major threats.
Here at Atoll Marine Centre, our conservation efforts are focused on the post-hatchling stage. Hatchlings are most vulnerable in their first year of life, particularly the first 48 hours. We receive turtles that have been taken as a hatchling to be kept as a pet by local people. We keep them in captivity in the first, most vulnerable stage of life in the hope that when we release them, they will have a higher chance of survival.
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