Miriam Abarca is standing on a wooden platform overlooking the Cahuil Lagoon, a small, salty pine-fringed body of water on Chile’s central coast. In the distance, birds weave through waist-high reeds and tourists paddle a rowboat over the lagoon’s placid surface.
“For me, this is paradise and pure magic,” says Abarca, who runs a small tour company that offers sightseeing trips around the lagoon. “This is the most valuable thing we have. Without it, I don’t know how we’d survive.”
The picturesque view was made possible by an ambitious project supported by the United Nations Environment Programme (UNEP), to revive the lagoon, which just a few years earlier had been brought to the brink of collapse by climate change and unchecked development. The effort was part of a larger push to preserve five wetlands strung along Chile’s central coast, a rugged, windswept land home to plants and animals found nowhere else on Earth.
Here, as in many parts of the world, pollution, climate change, invasive species and unsustainable tourism have been pushing wetlands towards the breaking point.
“Wetlands are one of the most important ecosystems on the planet and, yet, they’re disappearing at an alarming rate,” says Robert Erath, a Task Manager with UNEP who is overseeing the project. “That has to change if we’re to protect not only the species that call wetlands home but also the communities that depend on these landscapes for jobs and food.”
Globally, there are more than 1.2 billion hectares of vegetated wetlands, an area bigger than Canada, the world’s second-largest country. These watery environs – which include swamps, bogs and marshes – are a haven for wildlife, and they filter pollution and store planet-warming carbon.
But between 1700 and 2000, the world lost 85 per cent of its wetlands, many drained to make way for cities and farms. Chile’s coast, wedged between the Pacific Ocean and Atacama Desert, is dotted with examples of this. Some 85 per cent of Chileans live in this narrow strip of land, and as cities grew, they overran and diced up wetlands. At the same time, pollution from farms streamed into waterways spawning toxic algal blooms. The clearing of forests stripped land of its soil, speeding desertification propelling sediment run-off into rivers. Mass tourism disturbed the nesting sites of birds and amphibians, with local conservationists reporting that eggs were regularly trammelled underfoot.
But perhaps the greatest threat has been climate change, which experts say has caused rains to falter and wetlands to wither.
That is in part what was happening to the Cahuil Lagoon, which is in the suburbs of Pichilemu, a world-renowned surf town that sits on a sandy promontory in the Pacific. Dwindling rainfall during the normally wet winter months caused water levels in the lagoon to plummet, severing its seasonal connection to the Pacific Ocean. That starved the lagoon of the salt that makes its waters uniquely brackish. Over time, the lagoon shrunk, species began to die off and algae – fed by pollution – proliferated, releasing a powerful odour as it decayed, Erath says. The lagoon’s decline threatened a host of industries, from fishing to tourism to salt mining.
Two years ago, that began to change thanks to the effort supported by UNEP, and funded by the Chilean government and the Global Environment Facility. Engineers and the local government developed a plan to breach a sandbar that separated the lagoon from the sea, says Luis Araya, who coordinated the work in Cahuil under the Global Environment Facility. After months of preparation, during an especially rainy week in June 2023, they removed a section of the sandbar, sending saltwater cascading into the lagoon.
“We helped the lagoon recover its natural dynamic through this intervention and we did it in a sustainable way,” says Araya. “We hope that the wetland can continue functioning naturally for many more years.”
The return of the salt water has restored the salinity levels of the lagoon and reined in the algae blooms. Locals say tourism has since rebounded, as has the fishing industry.
Part of the project’s goal has been to save wetlands by merging conservation with economic development, a process known as sustainable land management.
“Conservation cannot exist in a vacuum,” says UNEP’s Erath. “The reality is that people in developing nations, like Chile, often rely on natural resources for their survival. The key to protecting fragile ecosystems, like wetlands, is to strike a balance between protection and economic development.”
Alongside the work with the sandbar, teams installed observation posts on the fringes of the lagoon for birdwatching, fenced off nesting areas and helped local officials develop a conservation protocol. That has made tourism less damaging to local wildlife and more sustainable over the long term.
The changes have sparked the rebound of several avian species, including the endangered pilpilen, says Lucia Zapata an environmental activist and member of the group Pichilemu Animal.
“It's amazing to see how species are thriving,” Zapata adds, sitting on one of the observation platforms overlooking the lagoon. “It’s a model that can be replicated not only in Chile but worldwide.”
Meanwhile, the experts working with the project supported Chile’s government as it developed Latin America’s first law to protect wetlands in populated areas. The law now extends to more than 100 urban wetlands. The Cahuil Lagoon has been slated for protection, something expected to happen by mid-2025.
Maisa Rojas Corradi, Chile’s environment minister, says the law is part of a larger government effort to protect and restore fragile ecosystems in tandem with local communities. “The issue of governance is crucial,” she says. “The experience of how to govern and make decisions around ecosystems is tremendously valuable because we hope it can be replicated with other types of ecosystems that need to reverse their degradation to address the biodiversity loss crisis.”
As of 2023, the project has helped 60 municipalities and 15 regions restore more than 11,000 hectares of wetlands. The work is intimately linked to the Kunming-Montreal Global Biodiversity Framework, a landmark 2022 agreement designed to halt and reverse the loss of nature. The pact includes targets calling for the conservation and restoration of landscapes, like wetlands, and for countries to “enhance” nature’s contribution to human wellbeing.
Back in Cahuil, tour operator Miriam Abarca says she is grateful for the lagoon’s recovery. She inherited her business from her parents and says the tourist infrastructure—including observation platforms—has been a welcome sight.
“The project is the most important thing we’ve had in, I think, decades,” she says. She’s hopeful that even with the project wrapping up in the coming weeks, the residents of Cahuil will continue to preserve the lagoon.
“The wetland must not stop being protected—not just the one in Cahuil, but all wetlands in the country.”
The planet is experiencing a dangerous decline in nature. One million species are threatened with extinction, soil health is declining and water sources are drying up. The Kunming-Montreal Global Biodiversity Framework sets out global targets to halt and reverse nature loss by 2030. It was adopted by world leaders in December 2022. To address the drivers of the nature crisis, UNEP is working with partners to take action in landscapes and seascapes, transform our food systems, and close the finance gap for nature.
The Global Environment Facility (GEF) is a multilateral fund dedicated to confronting biodiversity loss, climate change, pollution, and strains on land and ocean health. Its grants, blended financing, and policy support helps developing countries address their biggest environmental priorities and adhere to international environmental conventions. Over the past three decades, the GEF has provided more than $22 billion in financing and mobilized another US$120 billion for more than 5,000 national and regional projects.
