Ostional: Home of the Only Legal Sea Turtle Egg Harvest

One of my main goals as a mentor to my students is to offer them an opportunity to experience other cultures in an authentic way. When immersed in another culture, we often experience another way of thinking that can make us uncomfortable. I feel it is important to sit in that discomfort, and think deeply about why this situation makes us feel uncomfortable. Maybe even more important is to consider this other way of thinking while attempting to put one's own personal feelings aside. I think Matti Bradshaw has done a great job of fairly analyzing both sides of this issue, and she has presented some of the key issues that are being faced with the legal egg harvest in Ostional, Costa Rica in the following blog post. You can find out more about Matti here.


Costa Rica is a country rich in various customs that differ from those in the United States. The cultural exposure our team members have experienced in the last month has been eye-opening. Our host families and the town of Ostional have all been very welcoming and inclusive of us (even when our Spanish skills are slacking). The latest immersion experience was the Ostional Egg Harvest festival, which took place down the street from our houses. 

A large pile of olive ridley turtle eggs following cooking.

     The Egg Harvest Festival was filled with music, trampolines, cotton candy, a lot of Imperial (a local Costa Rican beer), and even traditional Costa Rican dances performed by some of the local children. Near the entrance of the festival there was a man selling plates of harvested sea turtle eggs to people as they walked by. The sight of so many sea turtle eggs in one place can be a little unsettling to a group of students dedicating their time to the conservation of the species, and I couldn’t help but wonder whether or not this practice is actually healthy for the population of Olive Ridleys. 

Brie learning to dance from the locals.

A few turtles remained the morning of July 5th. 

    To give a little bit of a background on Ostional, it is a seaside town that attracts many volunteers and tourists for the presence of its arribada beach. An “arribada” is a term used to describe the presence of mass nesting groups of Olive Ridley sea turtles that arrive once a month. During these mass nesting events thousands of sea turtles come ashore to lay their eggs. It is not known exactly what signals them to come ashore, but many believe it may be their ability to detect magnetic fields caused by moon cycles. The culture in Ostional is represented by sea turtles that appear on apparel, wall art, and in conversations constantly. Sea turtles are a way of life here.

     In the years prior to the turtle projects that have taken place in Ostional, the area was impoverished and the future appeared bleak. However, now due to the income from tourism in the last fifteen to twenty years there is a much higher quality of life and improved infrastructure. The tourism associated with the arribadas has produced many jobs for the people of this town. These jobs include tour guides, government officials related to running the Ostional Wildlife Refuge, Guardaparques that protect the beaches from poachers (this includes our host father, Pablito), and even income from harvesting the eggs. 

     The beach of Ostional has a very low success rate for hatchlings due to monthly arribadas that lead to anoxic conditions produced by the high number of eggs which decay in the sand, so during the first few days of the arribada locals are allowed to enter the beach and dig up eggs under the surveillance of the Guardaparques. Sea turtle eggs are a hot commodity in many Latin American countries, since they are believed to be an aphrodisiac that stimulates sexual potency in men. Many times, illegally harvested eggs from Leatherback sea turtles (Dermochelys coriacea) and Green sea turtles (Chelonia mydas) are sold in place of Olive Ridleys-whose eggs are noticeably smaller than many other species of sea turtle eggs. The argument that has been made is that allowing more of the less endangered Olive Ridley eggs to enter the market reduces poaching of the more endangered Green and Leatherback sea turtle eggs, since the believed presence of an aphrodisiac is not unique to a specific species.

     There is a lot of tension in Ostional when it comes to the discussion regarding the population of Olive Ridleys and whether or not the practice of harvesting eggs is sustainable. There are currently not any studies being done involving this topic, but it is estimated that around 5,000 eggs were collected when the July arribada was very short and probably did not exceed 10,000 eggs laid. The 5,000 eggs collected does not include the number of nests that are depredated upon by vultures and raccoons or the number that are lost to the anoxic conditions in the sand. As we left the beach each morning after a night of working the arribada, locals (including our host mother, Marilyn) walked in the opposite direction to begin harvesting eggs. The eggs are allowed to be harvested during the first seventy two hours after the arribada is announced, but arribadas in the wet season only last 3-5 days on average. The egg harvest period is not adjusted for these shorter arribadas, so locals are allowed to harvest the eggs after each night the mass nesting groups come ashore. Locals here claim that they only harvest 1% of eggs laid during arribadas, but there is not a lot of research to investigate this.

     Ostional is one of twelve Olive Ridley mass nesting beaches, so the species is not necessarily dependent upon the sustainability of this beach. However, hatchlings imprint on the beaches they are laid on, which will draw them back here in the future to lay their own eggs. If sea turtle eggs are being overexploited, there could be astronomical impacts that will not be known for years to come. 

Traditional Guanacaste dancing.

A large pile of empty turtle egg shells on the beach, likely depredated by vultures or dogs.

A batch of olive ridley turtle eggs cooking.

There is currently not enough research to support arguments for or against the harvest, so it is difficult to make suggestions on how the locals should control their own natural resources. Many locals believe that population estimates have been underestimated by researchers, so there is not a present worry regarding the sustainability of the arribadas. There are many positive and negative effects surrounding the egg harvest, but if the eggs are in fact being overexploited the way of life in Ostional will be forced to change dramatically.