Costa Rica is only the size of West Virginia, containing just 0.25% of the worlds land mass, yet has the distinction of containing 5% of the world’s biodiversity. Around 25% of Costa Rica’s land area is protected by national parks, making it the country with the greatest percentage of protected areas in the world. That being said, Costa Rica faces enormous challenges as it continues to develop. In coming to Costa Rica, I wanted to experience first-hand some of the diversity that I have always associated with this country. After doing some research I chose to volunteer with Pretoma, a non-profit organization. Pretoma has projects throughout Costa Rica, working within communities, thereby employing locals and enlisting anyone who wants to donate some time to work in the field. The program seeks to increase environmental awareness by educating people locally and internationally about the impacts of human development on coastal regions in Costa Rica (primarily focusing on sea turtles and sharks).
There are seven kinds of sea turtles in the world, four of which frequent Costa Rican beaches: the Olive Ridley, Leatherback, Green, and Hawksbill. All four are endangered, two critically. The threats to nesting sea turtles are abundant, and entirely linked to human impact, including: long line fishing/nets with no escape enclosures, habitat destruction due to light pollution (they will not return to nest on a beach where there is too much light because the hatchlings will be confused), and poachers on the beach.
To get to the volunteering site I had a long day featuring multiple bus transfers, travelling partially washed out roads, and traversing large mountains, all paired with my fledgling Spanish. But the trip was well worth it! I arrived at Playa San Miguel (located on the south western coast of the Nicoya peninsula) late at night and awoke the next day to find that my backyard was the ocean. Playa San Miguel has a population of about 300 people and about two and a half restaurants. The beach is long with cliffs and sea slug filled tidal pools at one end, and an estuary at the other, and is almost entirely deserted at all times. My daily routine consisted of running on the beach, eating meals at the local soda which served delicious typical home cooked Tico food (rice and beans were present for all three J), and working on the project. Most of our work occurred at night, and involved monitoring the hatchery and patrolling the beaches looking for turtles. The predominant type of sea turtle nesting at this site is the Olive Ridley turtle. They are unique in that they have a shell that is wider than it is long, and are rarely known to nest in arribadas, which occurs when hundreds of turtles emerge from the sea at the same time to nest. Each night we patrolled the beach in groups (using no lights) looking for the turtle tracks, which are about 2.5-3 feet wide, and can be found above the high tide mark. Sometimes we would see a turtle nesting, or just follow the tracks to where the eggs were laid.
Olive Ridley turtles can lay up to 120 eggs in one nest. They dig a tube down into the sand, which has a wider mini-cavern at the bottom where the eggs to rest; this task is accomplished using only their back flippers. The whole process is actually quite quick, I was surprised by how fast a full grown ~120 pound marine animal can move so quickly on land. When we came upon nesting turtles it was important not to use any lights or stand in front of them, or else they would potentially head back to the water. But once a turtle started laying the eggs, she would become totally oblivious to us and we could take measurements of the shell and track size, then tag the flippers, and collect the eggs as she was laying them. All of the information collected from the turtle goes into a database, which helps to track turtle health and migration patterns. The eggs were collected so that they could be brought to the hatchery, where they would be safe and the turtles only exposed to red light so as not to disturb the process. Eggs are also brought to the hatchery to protect them from poachers on the beach (who would take them before the morning), as well as from dogs and other accidents.
During our patrols we occasionally ran into poachers, and even when we did not see them, we sometimes came across nests that had been dug up. It seemed that there were no outright hostilities between the conflicting groups, and the system operated on a first-come first-served basis. To combat this constant threat of poaching, Petroma has people monitoring the beach all night long in shifts. The poachers take the eggs to sell them, and from what I was told they can make up to $20 per nest, which is a lot considering that the average wage in Costa Rica is $2 per hour. When successful in collecting the eggs, we returned them to the hatchery to bury them (in the same type of nest). The correct temperature is very important to their development, so the nests we created had to be similar to what the turtle would dig, with an incubation period of about 45-55 days.
I was lucky to be there when turtles were still nesting and the eggs were hatching. So while we were patrolling at night we would check the hatchery frequently, since the eggs were likely to hatch in the dark (giving them an advantage over the tremendous obstacles that awaited them). The reason that turtles lay so many eggs is that the likelihood of a baby turtle actually making it to adulthood is around .01%. For the most part they all hatch simultaneously, which gives them an advantage, then they immediately start heading for the ocean based on sight and smell (another reason why light pollution can be harmful, as it can attract them inland). Before even getting away from shore, they are picked off by birds, crabs, and fish, and can be baked in the sun quickly. They have no defenses, and are just about bite-sized, so basically anything that wants to eat them can pretty much do it. After escaping the nest, they have to survive to about 15 years of age before they will return to nest. Surviving 15 years is a huge feat in itself, since the largest threat to turtles is not the poachers on the beach, but the fishermen offshore. Turtles need to go to the surface to breathe, so if they are caught on long lines (used to catch swordfish and sharks), or in fishing nets (typically used for shrimp), they will suffocate and die before ever making it back to nest. Long line fishing is a huge problem in Costa Rica, as it is all around the world. In Costa Rica this technique is used to catch sharks, predominately for shark fining (which is illegal), and done on an industrial scale by international vessels (upwards of 100 million sharks are reportedly killed solely for their fins worldwide). It seems that in Costa Rica the laws are in place to protect animals from poaching, overfishing, and shark-fining, but the enforcement is lacking. When thinking about all the challenges the turtles face, it’s amazing that they survive at all.
http://www.youtube.com/watch?v=CCUGLaHDujk
Successful and unsuccessful methods of protection:
Involving local communities and educating them on human impacts, such as over fishing and habitat destruction is critical. Even simple things like shielding open-facing lights and installing exits in large nets for bigger marine animals can have a big impact. Tourism is the biggest source of income in Costa Rica, and people come here to experience the biodiversity. This source of income can be more lucrative and sustainable for communities than the poaching of eggs. The latter is unsustainable, and as with all endangered populations, there is a critical number that can be reached at which point there is not enough genetic diversity for a species to survive.
(http://playagrandeinfo.org/docs/leatherbacknature.pdf)
An example of this may be found in Playa Tamarindo, where we have been staying for the past six weeks. Tamarindo lies at the center of what was once a substantial nesting area for the Pacific leatherback. However, light pollution and over-development has almost totally wiped out this nesting area. So now the people who come here to see Leatherback turtles end up paying high prices for guides who may not even find any. While there are still turtles nesting to the north and south of Tamarindo, there are concerns regarding the aforementioned point of no return, as Pacific Leatherback turtles are critically endangered.
To see what you can do to help:
http://www.pretoma.org/
