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  • Writer's picturekathbeasley4

Turtle Conservation on the Osa Peninsular



In the summer of 2019, I travelled to Costa Rica to volunteer with Frontier on a conservation project on the Osa Peninsula. Despite the intense heat, humidity and basic living conditions, I loved every second of the time I spent working in the jungle and it cemented my deep-rooted passion for tropical forests, reaffirming my desire to follow a career in tropical conservation. I immersed myself in the work, carrying out surveys to monitor the local populations of birds, mammals, amphibians and reptiles. I have never felt so alive.


A large aspect of the project’s work was turtle conservation as 6 out of the 7 marine turtle species are threatened due to human activities. The beaches along Carate are popular nesting sites for Olive-Ridley and Green turtles. However, the turtle populations here are in danger. Nests are frequently poached by hunters, predated by domestic dogs or washed away by the tide. One of the aims of the project was to investigate the impact of predation on nest success and assess the impact of using bamboo cage coverings on nest predation rates.


Upon finding a nest whilst on beach patrol, the GPS location would be recorded, along with other details such as species of turtle. This was determined from the size and shape of tracks in the sand. The GPS locations of the nests were plotted on a map using GIS to allow us to observe any patterns in nesting locations which could then be compared with the hatching success later on in the season, where nests would be dug up after the expected incubation period to see if they had indeed hatched or not. This provided data that helped determine the effect on tidal zone and nesting success.


A predated nest


Once a nest has been recorded, a decision would be made as to if it needed relocating or protecting. If the location of the nest was deemed safe, a bamboo cage would be placed over it. This would prevent dogs from digging up the eggs and reduced predation rates from 22.8% to 13.8% according to Frontier’s findings. However, there were many occasions where a nest site was in an unsafe location. This meant it was either in the inter-tidal zone so risked being washed away or was in front of a tourist resort, where the lights from the villas could confuse hatchlings causing them to travel inland instead of towards the sea.


A bamboo cage placed over a nest


In these cases, the nest needed to be relocated to maximise the hatching success. Only 1 in 1000 hatchlings survive to adulthood, so they needed all the help they could get! Hatcheries were constructed, it was very hot sweaty work in that tropical sun! The nest would then be carefully dug up, and the clutch would be collected and relocated to the hatchery. Each egg in the clutch were counted and placed gently into a bucket. It is very important when handling turtle eggs that you do not rotate them as this could damage and even kill the embryos. With Green turtles laying between 95-120 eggs and Olive- Ridley turtles laying 80-120, it was a lot of eggs and responsibility for you to carry many kilometres along a beach at 4 am in the morning! Once at the hatchery they would be placed into a new nest chamber, where temperatures were constantly recorded and when the hatchlings emerged, they were released on the beach to start their journey to the ocean.


Turtle populations are declining, and we are the reason why. Not only do they face the threats brought by commercial fishing where turtles are regularly killed by trawlers or as by-catch, but climate change is putting their existence in the balance. A turtle’s sex, like other reptiles, is determined by the temperature the eggs are incubated in. For example, if a green turtle lays her eggs in sands that are around 28 degrees, the clutch will hatch as males, but if it is warmer, a temperature of 30.5 degrees, females will emerge. With climate change causing temperatures to rise around the globe, the average temperature of sand is rising, leading to a female bias population in turtles.


An Olive-Ridley Turtle's eggs being collected as they were laid as she had chosen an unsafe site to nest.


Cutting your carbon emission to tackle climate change is one of the many ways you can help these beautiful creatures, as well as reducing your plastic waste to minimise plastic pollution in the oceans and making sure to buy sustainably sources sea food, such as MSC Certified products.


Having the opportunity to participate on this conservation project was incredible, and I will never forget the moment when I saw the first hatchling of the season. But like many species, they have suffered at humans hands and now need our help.


An exhausted me holding an Olive-Ridley hatchling to move it slightly closer to the ocean for it to begin its journey.

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