Saving a Mangrove Forest: A Costa Rican Community’s Sisyphean Task
<p>Costa Rica’s largest mangrove forest is receding. In the Térraba-Sierpe wetland, an area under pressure from African palm plantations, “we’re trying to repair what our ancestors did,” said one reforester. But the rising sea can’t be stopped.</p>
More than four decades ago, when Rebeca Espinoza was a little girl, her father would travel along the Sierpe River and through the mangrove channels to fish and pianguar — extract mollusks from among the roots and mud of the mangrove swamp, a practice known in other Central American countries as curilear.
In those days, a dye extracted from the mangrove tree was used to dye leather. Just like Rebeca’s father, hundreds of residents living around the Térraba-Sierpe wetland supported their families by harvesting ink and wood from mangrove trees.
Adrián, who was a teenager at the time, would wade through the mangrove mud in search of the most leafy trees to cut down and sell their trunks as lumber; he used the thinner ones to make charcoal.
The subsistence of the impoverished local population, the clearing of mangroves for salt flats that no longer exist, and the hundreds of hectares of African palm plantations on the edges of the wetland —which are still being exploited today for oil production— have fueled global climate change, resulting in an environmental catastrophe.
The Térraba-Sierpe wetland is located in southeastern Costa Rica, about 140 kilometers from the capital, San José. It spans 30,654 hectares on the Osa Peninsula. Of this total area, more than half consists of mangrove forest —17,732 hectares— making it the largest mangrove forest in Costa Rica and one of the largest in Central America.
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According to a study by the University of Costa Rica (UCR), mangrove trees in this area reach heights of up to 25 meters, and the species found here include the piñuela, red, caballero, botoncillo, and black mangroves.
The UCR found that, from 2008 to 2016, more than 1,300 hectares of wetland were drained for cattle ranching and African oil palm cultivation. According to local sources and media reports, the crops belong to small-scale producers in the area who supply the company Palma Tica, which was founded in the 1930s by the United Fruit Company. In the Sierpe River basin, workers are busy harvesting clusters of African palm fruit, and in the vicinity of the wetland, there are hectares of African palm plantations.
In 2009, alarm bells went off for university researchers when they came across hundreds of dead mangrove trees in the Sierpe wetland. The researchers put forward two hypotheses that year: first, that all the sediment was being carried by the river to that area and that increased wave action was pushing it toward the mangrove forest; and second, that due to climate change, sea levels had risen, flooding the forest areas —which must maintain a balance between fresh and saltwater— with saltwater.
These hypotheses are currently supported by forest engineer Christian Peralta, who has been working in the area since 2018 as coordinator of the mangrove conservation program with the organization Osa Conservation.
“That damage is impossible to stop, since you can’t stop the force of the sea,” he said. “That’s due to the rise in sea level caused by the melting of the poles, which is happening far away from here. In the long term, it’s impossible to reverse; the only option left is to try to reforest other areas so that, as the mangroves grow, they can protect the coast.”
Faced with the damage from climate change and the deforestation of the last century, residents of the Sierpe communities —Rebeca Espinoza, the pianguero Orlando, and Adrián— traverse the mangroves to work on their restoration and have implemented other types of projects to reduce their exploitation of these resources.
“We’re trying to repair what our ancestors did and counteract the damage from climate change. Now it’s up to us, the children, to try to restore what was destroyed,” said Rebeca during a mangrove seed-planting event in one of the areas that was cleared and which, 40 years later, they are trying to restore.
Orlando Salazar, 48, is a pianguero from Sierpe; he has been traveling through the wetland’s mangrove forests since he was a teenager to harvest mollusks and sell them. Fifteen years ago, while navigating the area known as Boca Zacate, he noticed that dozens of trees were dead, and the problem has been growing ever since. Now Orlando is dedicated to monitoring and reforesting the mangrove forest alongside other piangueros and piangueras from Sierpe.The area where the mangrove forest has died looks as if a hurricane had swept through it: the trunks are fallen mangrove trees, up to 30 meters long. According to experts from Osa Conservation, this is caused by excessive salinization and sediment buildup due to increased wave action, which ultimately suffocates the mangrove forest.The Térraba-Sierpe wetland, where the mangrove forest is located, is surrounded by African oil palm plantations. According to a publication by the University of Costa Rica and the National System of Conservation Areas (SINAC), more than 1,330 hectares of land adjacent to the wetland in the region were drained to make way for African oil palm cultivation and livestock farming.On the banks of the Sierpe River, which forms part of the wetland, the fruit of the African oil palm —harvested from the plantations in the area— is collected on small docks. For forestry engineer Christian Peralta, the ideal solution would be to stop cultivating these crops: “To reduce the impact on the area from the sediment flowing down from the African palm plantations, those crops should be discontinued and nature should be allowed to take its course as the land degrades.”
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Rebeca Espinoza and Domingo Álvarez have dedicated about five years to mangrove reforestation. They do this in areas that were cleared years ago for timber. With the help of environmental organizations, they have reforested more than 200 hectares of mangrove forest.Rebeca Espinoza walks through the mangroves of Sierpe to collect mangrove tree seeds in the area known as Boca Guarumal. Those seeds are planted in restoration areas where, for decades, dye was extracted from the mangrove bark for the leather industry — a trade her father was involved in. “We’re aware of the damage our parents caused to the mangrove forest, and that’s why we now have a responsibility to try to restore some of it,” she said.Red mangrove and piñuela seeds collected in Sierpe. The community associations of piangueros have organized themselves and, according to the Térraba-Sierpe Association of Piangueros, have planted more than 42,000 seeds of the various types of mangroves found in the area.In the restored mangrove areas, monitoring is ongoing. The piangueros, with the help of environmental experts, measure the height of the new trees and their trunks, and check a tag to verify the date they were planted. As shown in the image, they also verify the types of mollusks growing there. The more species found within a given radius, the healthier the mangrove is growing.The Térraba-Sierpe wetland falls under the jurisdiction of Costa Rica’s National System of Conservation Areas (SINAC). As a protected area, SINAC has imposed restrictions within the mangrove forest including a limit on the harvesting of the piangua mollusk. Piangueros are allowed to harvest only 350 mollusks per day for 20 days each month. Records are kept on a card that the piangueros turn in to their cooperative to track how much is harvested and try to maintain a balance.For years, Domingo Álvarez, Rebeca Espinoza, and Adrián Torres have made a living from what the mangrove forest provides. Adrián, 67, lived through the era when the mangrove forest was deforested to extract ink for leather. Domingo and Rebeca’s parents, like Adrián, cut down hundreds of trees in search of the prized dye. Decades later, as the tides have encroached on the mangrove forest, the three have set themselves a goal: to reforest and take less than the mangrove forest produces.
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The Térraba-Sierpe Piangueros Association is seeking new ways to reduce its dependence on the mangrove forest. A year ago, they launched a beekeeping project in which they installed hives within the mangrove forest to produce honey for their own consumption and to sell through the cooperative. For now, producing honey for their own use saves the piangueros’ households money on sugar purchases. They hope to produce enough to sell by 2027.In the Térraba-Sierpe wetland, the piangueros maintain a decadeslong tradition. Orlando says it is impossible to separate oneself from the mangrove environment and make a living from the area while respecting the ecosystem: “I’m worried about the future of this place, because we’ve grown up here for generations, and my children are growing up here too. If we don’t take care of the mangrove forest, our children or my grandchildren won’t have a place that provides them with even a little sustenance,” he said as he returned from a day of monitoring with his 11-year-old son, Neymar.Since 2018, the communities of Sierpe and the piangueros’ cooperatives, together with environmental organizations working in the area, have restored at least 250 hectares of mangrove forest. The mangrove forest has lost 9.83 percent of its coverage, equivalent to 3.73 square kilometers, according to a study by the UCR. Experts believe the area is impossible to restore: “There’s practically nothing that can be done there,” said forest engineer Christian Peralta of Osa Conservation. “The sea will continue to rise and create more land and beach where there wasn’t any before. It’s something that can’t be stopped.”
