Sea turtle and mangrove conservation in Costa Rica
From the first days of November to about mid-January I had the pleasure to cover the role of Research Assistant working for Latin American Sea Turtles (LAST), in the Osa Peninsula – on the Pacific coast of Costa Rica. My role was to lead groups of volunteers during the various activities of the research station, which ranged from gathering scientific data – to send to the University of San José for further analysis – to more hands-on conservation efforts. Our main projects were two: sea turtle population data gathering and mangrove reforestation.
Sea turtles are currently facing great threats worldwide. These range from global warming to incidental fishing (bycatch and/or long lines), to sea pollution, to habitat loss and poaching – which is still a big issue in Central American coasts even though illegal in most countries. To fight some of these problems, LAST has set up a project in the beaches of Pacuare, in the Carribean Coast of Costa Rica, as well as the project to which I participated to, in Osa. In Pacuare, volunteers patrol the beaches for nesting females, protecting them and their eggs from illegal poachers. In Osa, the research assistants and the (mostly short-term) volunteers focus on the in-water life stage of juvenile and adult sea turtles, monitoring the health of the population as well as collecting data on the various individuals encountered.
When I was in Osa, the turtle data was gathered at least twice a week, by going out in the Golfo Dulce with LAST’s boat. A 100 or 200m x 5m net would be deployed early in the morning, and then for 6 hours we would wait for a turtle to be captured. Two main species are found in this gulf: the green turtle (Chelonia mydas) and the hawksbill turtle (Eretmochelis imbricata). Once captured, in less than 10 minutes all the data was acquired. After disentangling the turtle we would check that he/she was ok: any injured turtle would be taken to a rescue centre immediately. Luckily we never encountered any ill turtle, and the local population was overall very healthy. Then, we would measure the carapace and plastron (underside)’s dimensions, as well as tail length and cloaca position, useful data to sex the turtle and gain insight on these species’ growth rates. Finally, we would tag the turtle for monitoring the population on a broader scale: these turtles can travel extremely far, and our tags would be able to be spotted by other research stations along the coast. A tissue sample would also be collected for genetic mapping.
The second project that we carried out in Osa was mangrove reforestation. Mangroves and plants only found in the tropics. They are extremely important as they provide habitat for a great variety of animals, including birds and crocodiles, as well as being a nursery for juvenile fish and sharks. They also protect the coast from wave action and salt intrusion. Unfortunately mangroves have been heavily deforested over the years, due to human urban development on the coasts. Over the last four years, LAST has worked towards reforesting the coast close to the field station to re-establish a healthy environment. Our efforts focused on three mangrove species that are naturally found in this area: the red mangrove (Rhizophora mangle), the white mangrove (Laguncularia racemosa) and the commonly called “Piñuela” or “tea mangrove” (Pelliciera rhizophora). LAST manages a nursery where the seeds are grown to seedlings, and then the seedlings are planted by volunteers in specific locations along the coast.
Overall this experience was incredible, and not only because of the invaluable opportunity to work with live sea turtles, amazing endangered animals that sorely need action to be protected. I was lucky to meet fantastic people, all volunteers putting effort towards the conservation of this Costa Rican stunning environment, so rich in a biodiversity that is ever-declining. I woke up every morning to scarlet macaws, tucans, basilisks and iguanas, and went to bed listening to the loud calls of hundreds of rain and tree frogs (check out my ‘wildlife photos‘, some of them come from Osa!). It made me realise how important it is that as many of us as possible work towards biodiversity conservati0n – it is now or never, and the more effort we put the more we’ll be able to change the terrible declines that most of the species in these areas of the world are facing.