Understanding the Age of Extinction
We are living through a biodiversity crisis, or what scientists are calling the ‘sixth mass extinction’, as around 1 million species face extinction, many within decades.
May 7th 2021
In this detailed report, volunteer Rosemary Jambert-Gray tells us about the experiences she had during her time volunteering at the Ostional Refugio National de Vida Silvestre in Costa Rica. She assisted the local organisation with the conservation of several endangered turtle species, whose future remains uncertain due to the continued illegal egg harvesting. She explains how education is the key to securing the future of these turtles, which have been roaming our planet for millennia. Please read below for the full report and some great photos from her project.
I stayed two weeks in a local homestay in October 2016 during the wet season. I worked as a volunteer at the Ostional Refugio National de Vida Silvestre, on the west coast of the Nicoya Penisula in Costa Rica. Aside from my own observations, sources of the following information include that originally supplied by Working Abroad, the organisation in the UK who arranged my stay. Another source came from the orientation I received from Mr Jairo Quiros Rosales, Research and Volunteer co-‐ordinator. He has been working for seven years at the centre and was invaluable for his shared knowledge, understanding, wisdom, insight and passion he has for turtles. Other information is anecdotal as spoken in conversation between myself, Jairo and Idioa Martinez, the other volunteer who spoke fluent Spanish. She had become familiar with the village during the weeks she had been working there.
We are all fervent conservationists, with shared concern for the management and care of turtles in Ostional. As volunteers we became participants in the University of Costa Rica Investigation Research Programme, spending all our working time out on the beach in the day and night. We helped collect data about population dynamics, nest density and hatchling success. We also took part in nightly patrols, where we monitored turtles, recording numbers of those who were already tagged and tagging those without. Biometric data such as carapace dimensions, flipper size were also recorded. In addition eggs were counted and turtles checked for markings and injuries.
In Costa Rica there are 166 protected areas, covering 40% of the country set within National Parks. The Costa Rican Ministry for the Environment -‐ MINAE – is in charge of all the conservation areas. MINAE is supported by SINAC and ACT, which have responsibility for specific areas across the country. Ostional Wildlife
Refuge (ADIO) was founded in 1987. Family members can join as members at 15 years. As well as being able to take part in legal egg harvests, they have additional responsibilities for beach clean-‐ups, hatchling release, nest protection, environmental education activities and promotion of turtle conservation.
Costa Rica boasts 50 nesting beaches, used by 5 out of the 7 species of the world’s sea turtles. Three nest at Ostional; Olive Ridley, Leatherback and Pacific Green. Jairo says he would like to see and create a local hatchery to protect Pacific Greens and Leatherback eggs, as they are an endangered species. However this plan is dependant on whether funds can be made available.
Egg harvesting is often blamed for reducing the numbers of viable eggs, and is cited as a major cause for conservation concern. Arguing for a halt to this activity blurs the difference between the two kinds of egg harvesting. Set within a conservation framework, the legal first, regulated by ADIO, takes place 2.5 days after the first day of the Arribada. The illegal second -‐ driven by the black market – appears to take place after the Arribada when beach patrols are minimal.
l understand and accept the argument that legal harvesting helps to reduce the negative impact on nest density. However I am adamant that when ADIO members fulfil their other duties to the turtles, improve conservation education for children and control their dogs, illegal raiding of nests could stop.
Ostional Playa is 7 kms (4.3miles) long. It is part of the protected area, a total of 17 kms running from Punta India in the north to Punta Guiones in the South. The volcanic beach sand is black and littered everywhere with white eggshell debris, rotted dead stinking eggs, driftwood and some plastic rubbish. The sand covering thousands of unmarked nests is soft and makes walking on the beach a hazard.
The beach is pock marked with holes dug by dogs. Eggs are also hunted and destroyed by semi-‐feral dogs accompanied by the mass of black vultures. The dogs, owned by the local community, are allowed to roam free on the beach and often do so in packs. Their owners do not stop them. Digging at will, they are a menace to the viable nests. The vultures peck into the freshly dug nests and eat the eggs when the dogs leave.
Ostional beach is famous for the Arribada (arrival). Hundreds of nesting Olive Ridleys come up onto the beach approximately once a month all year round, usually around the last quarter of the moon. The turtles started coming in their masses around 1950. However it seems nobody understands why. The enigma continues today, as the timing of each arrival remains unknown and unpredictable. There are only 9 beaches worldwide that do this, with Ostional being the second most important.
In the summer the Arribadas are smaller and tend to last for shorter periods of time, around 4 days maximum. In the dry season the temperatures are hot and the sand dry and loose. With holes often collapsing, turtles return to the ocean without laying their eggs. There is greater regularity of an Arribada during the rainy season where hundreds of turtles become thousands. Nesting takes place on a different part of the beach, and last longer, usually up to 7 nights. The wet sand conditions are good for maintaining nest holes.
In the Arribada I experienced, it was estimated that over 100,000 turtles made their nests in the first four nights; around 61,000 on the first night, 27,000 the second and 3,000 on the third. Turtles continued to nest in the nights following these first busy days. Each turtle normally lays round 100 – 120 eggs. These 100,000 turtles therefore are computed to lay between 1 – 1.2 million eggs.
The nesting success of an Arribada is about 10 – 15%. This percentage is lower when compared to solitary (non-‐synchronised) nesting success of around 90%. But with a higher population taking part in an Arribada means survival of 100,000 – 180,000 eggs. The generally accepted survival ratio usually quoted is 1,000 hatchlings to 1 adult. Thus 100 – 180 are expected to survive as adults each month from the first four days.
However, this number is probably over optimistic. As discussed below, there are a number of predators, which appear to further compromise survival rates, including; people, birds, dogs and other animals such as crabs.
Ostional is a small isolated village, with an estimated population of around 500; most have been described as related to just four families. It is accessible only by special transport, usually 4×4 vehicles. The roads are un-‐surfaced, stony, rough and potholed. When it rains the soil turns to mud and the rivers swell making crossing the fords more difficult. There is some public transport, but only 3 times a day in two directions, north towards Santa Cruz and south towards Nosara. Motorbikes seem to be the favoured form of transport and it is not unusual to see families riding pillion. Taxi rides to the nearest town of Nosara, 7 kms (4.3miles) away, costs $30 one-‐way.
The Ostional Playa protected area also extends 200m inside the coastal line. Families continue to live in houses built within this strip in the 1950’s. Although they are allowed to repair their houses, they are not allowed to build or sell. The houses are very basic and appear dilapidated. To help cool the house, the walls and the roofs do not meet. Daylight can be seen through holes in the rusted, corrugated iron roof. Water is collected in buckets when it rains. There is no hot running water, which appears to drain directly onto the ground outside. Electrical wires hang from ceilings and walls. Power is often cut off with nobody knowing when it will return. An elderly couple, neighbours to my homestay family, lived in a tiny two-‐roomed house. The stony dirt on the outside continued on the inside as they had no separate floor.
The family is very important. The house where I stayed was owned by a 64-‐year old widowed grandmother, her son, his wife and their two children, aged 10 and 4. They were very fastidious in being clean and in what they wore. The grandmother is always cleaning the house and washing clothes. The little girl and boy were always dressed in clean and neat clothes. The family unit seemed very tight and the two siblings appeared close and happy. I only heard the little girl cry once in two weeks. In the main room of their neighbours described above, facilities were very poor. But pride of place is a brand-‐new washing machine and she was generous in spinning my wet clothes for me.
There are three small shops that sell groceries, including licensed turtle eggs. People can socialise at the two small restaurants and also a couple of bars. Religion is very important, with residents attending three churches; Catholic, Evangelical and Jehovah’s Witness. The ubiquitous football ground looks well cared for and lies next to the Colegio – the High School for children aged 11 years and more.
Children younger than 11 can only attend school on one day a week because there is no local teacher. Teachers for both the primary school and Colegio commute from outside, usually from Santa Cruz, a town about two hours drive away. During the wet season, excess water can cut off roads. This prevents the teachers from coming to Ostional. In addition, teacher numbers are minimal and children are taught in ‘sittings’. By attending weekly, physical care of the community is maintained by a local doctor.
The average income in Costa Rica is between $600‐$800/month. In a country described as the most expensive in Central America, this income can be inadequate, even for those whose income is regular. The high unemployment rate in Ostional is often cited, with under-employment adding to the problem. For instance in my homestay, the grandmother’s son worked three days a week.
Volunteers staying in local homestays can help provide an additional source of income by paying around $28/day for a bed and three meals. Distributing volunteers around families helps spread the benefits, but also means this is not a regular source. Volunteering companies suggest that such incomes help to discourage harvesting. I did not see this within my homestay household.
The son mentioned above was happy to supplement his money by monthly legal egg harvesting. He and his wife were both ADIO Association members. With high un/under employment they were reliant on monies received via the Arribada, where each member can earn $100/month.
Legal egg harvesting
Prior to the formation of ADIO in 1987, in an unregulated market, residents poached eggs to sell. It was an American academic, working at the University of Costa Rica, who advocated egg harvesting should be controlled and permitted under government licence. Dr Duncan Robinson Clarke suggested legal harvesting helped benefit turtles by removing early nests that can potentially become infectious.
Turtle egg consumption is only endemic to Costa Rica where it is considered an aphrodisiac. Ingestion is usually in restaurants and bars found across all 7 provinces of Costa Rica. Eating raw eggs in bars with Sangrita (a tomato based preparation) is especially popular.
Egg harvest takes place within the first 2.5 days of an Arribada, along a designated stretch of beach. There is no commercial use after this time as embryos begin to develop. Egg harvesting appears to be a community event, where the labour is gender divided. Men take responsibility for finding the eggs and washing them, whilst women collect them up into sacks and distribute the washed ones into officially marked ADIO bags.
Men use their feet and toes to find soft sand. They dig down gently with their hands. When they find a nest they take out 5 eggs and lay them to the side. Noticing the marked location of the nests, women then collect the rest and put them in sacks. However as the eggs are covered in a liquid lubricant (Museilago) used for egg development, this is washed off to stop the eggs developing. Men do this by taking the sacks to the sea. Once packed into the marked bags, the eggs are ready to be sold.
In addition, after the end of harvesting, Association members are permitted to extract 200 eggs each for themselves. The eggs can be sold but the price is kept low to discourage illegal harvesting.
Whilst the community at large upholds this agreement, uncontrolled harvesting continues outside the 2.5 days of the Arribada. The beach is usually well manned by Police and Rangers during the peak, but stop after the first few days. However turtles continue to arrive and lay in a more solitary fashion. Illegal poachers, described as coming mainly from nearby Nosara, harvest these eggs. There are also some local residents suspected of poaching.
Beach patrols continue by poorly paid security guards who were described as earning $13 for a 12 hours shift. Although they are aware of poachers they appear ineffectual in stopping them and even described becoming victims themselves of robbery. The nearest police station is in Santa Cruz. Some individuals try to stem the numbers of poached eggs by relocating the nests in efforts to hide them. Even though they are not licensed to do this, they say this is the only way they have found to frustrate the illegal poachers.
Poachers seem to be blatant in their actions. Not only seen at night, their presence is obvious during broad daylight. They are seen patrolling the beach, carrying plastic bags. Eggs sold on the black market are said to meet demands for money fuelled by unemployment, drug and alcohol abuse. Apparently 12 eggs sell for as little as $1. On one occasion somebody had dumped around 70 eggs at the back entrance to my homestay. By morning these eggs had all been eaten by satiated looking vultures.
On reading the above, the picture appears dismal. Such descriptions could substantiate the demand that egg harvesting be more stringently monitored. However the main danger to egg survival is from natural causes, which reduces survival rate to 30%. Three reasons are cited for this.
Firstly the turtles are the main culprits for over extraction of eggs, which are displaced and destroyed in the nesting process. Turtles usually nest 2 – 3 times, resting for 3 weeks when they swim in the ocean to eat. By constantly digging new nests, they dig up older ones and even dislodge newly developing hatchlings.
Secondly due to high tides and swollen rivers, especially during the wet season and high tides, there is a natural erosion of the beach, which exposes previously hidden nests. The vultures greedily eat these eggs.
Finally in areas of high nest density too many nests are laid in close proximity. Old, dead eggs contaminate new ones with bacteria and fungus. For instance in a 1 metre square area I helped to explore, 12 nests were found. Of these only 4 were viable, the other 8 lying close by were old and infectious. The ratio of viable to dead nests is estimated to be around 1:3. There is also less oxygen. In the summer season high temperatures exacerbate the problem, high nest density caused 0% survival.
Thus by allowing a legal egg harvest, Dr Duncan Robinson Clarke argued that legal and controlled harvesting at the time of the Arribada improves survival rates. Firstly because eggs laid in early nests become dislodged and broken, infecting newer eggs. Contamination is also controlled by decreasing nest density. Further by controlling where harvesting can safely take place, dangers of illegal and uncontrolled harvesting are eliminated.
This argument is a strong one. In a previous experiment, an area of beach was marked off as a protected area for nests. The outcome showed the survival rate was worse than on the harvested beach. However prior poor methodology and data collection has negatively influenced the current situation. Data are now being recollected under stricter methodologies, aided by volunteers.
Thus legal harvesting appears to reduce the negative impact of nest density. However as indicated above, dogs need more control. There is a debate on how this could be achieved, ranging from stopping reproduction via neutering, to rounding up and annihilation if their owners continue to allow them to roam freely.
To be able to take part in legal egg harvests, ADIO members are also held responsible for beach clean-‐ups, hatchling release, nest protection, environmental education activities and promotion of turtle conservation. On one single occasion, I was able to witness a woman sitting on the beach in the early hours overseeing newly emergent hatchlings. In addition, as volunteers we did regular beach clean-‐ups. We never witnessed any residents doing the same or offering to help.
ADIO members also have not been evident in protecting nests. For instance the more endangered Pacific Green turtles also use Ostional beach. These eggs have traditionally been left to mature. Sadly however whilst there, I witnessed devastation of a newly laid Pacific Green’s nest of 72 eggs. Whilst she was laying we were aware of at 3 men showing an interest in our activities. Suspecting illegal activity and to protect from dogs, we carefully camouflaged the nest. Despite our efforts, the following morning the nest had been dug up and the eggs stolen. The guard who alerted us to her presence was devastated and angry that local people had not protected the nest and the poachers stopped.
An additional part of their ADIO role is to promote environmental education to children, the next generation. As younger children only attend school once a week, this offers time and space for positive development. The centre for the Ostional Refugio National de Vida Silvestre has plenty of room and could be used for instruction.
Education could cover two major areas, turtle awareness and environmental guardianship. Via colourful and dynamic wall charts and online games, children could be exposed to details about the life cycle of turtles. Included in this is the current concern that turtle populations could disappear within the next 50 years.
Discussion on the importance of beach clean-‐ups could be stressed at such session. From rubbish they are encouraged to collect, children could create their own imaginative pictures including how many years it takes to degrade and the danger posed to turtles. The children can be instructed that plastic takes 500 years to degrade. They can shown films where ingestion of plastic rubbish causes turtle injury and death. They can be taught about the dangers posed from fishing. This could even include educating local fishermen not to use hatchlings as bait.
Education and raising awareness about turtle welfare will help to educate the next generation of ADIO members. Currently turtle eggs are seen as a commodity to be sold to raise money. Children should come to realise the importance of caring for their local environment and take pride in their beach, nests and eggs as a way of ensuring the continuation of sea turtles. It is sobering to remember that whilst facing extinction today, turtles are 150 million years old, resident on this planet before the dinosaurs.
If you are interested in working with sea turtle conservation efforts as a volunteer in Costa Rica, then you can find all of the projects here.