When subsistence fishermen on the island of Chira couldn’t find clams in Costa Rica’s lush Gulf of Nicoya, they dug deep into the mangrove forests where the small shellfish liked to hide.
Women on the island soon realized the fishermen were actually hacking away at their own livelihoods, says Emily Pidgeon of Conservation International, with fewer species of fish, rays and other animals returning each year.
So the women founded the Chira Island Women’s Collective in part to protect the threatened mangrove forests. They warn that the plants do much more to sustain the town of Palito than anyone knew when they began pulling up their roots.
Around the world, coastal communities and environmental groups alike are learning a similar lesson, and global environmental organizations like Pidgeon’s are taking note. Preserving waterlogged resources like mangroves, wetlands and seagrasses doesn’t just nourish local communities–they also capture and store a surprising amount of carbon that might otherwise contribute to global warming. Scientists call it “blue carbon.”
“A lot of attention has quite rightly been put on forests, but we need all solutions from all parts of nature,” says Dorothée Herr, who works on coastal ecosystems with the International Union for Conservation of Nature. That’s not always an easy pitch, Herr says, because people want to live on the coastline. “There’s a lot of pressure on these ecosystems.”
As much as half of the world’s mangrove habitat has disappeared over the last century, much of it destroyed by fish and shrimp farms, as well as seaside real estate developments. That’s a big mistake, says Herr, because while these aquatic woodlands make up less than one percent of the world’s tropical forests by land area, their destruction accounts for as much as 10 percent of emissions from deforestation globally.
With thick mats of roots sometimes six meters deep, healthy mangroves are a natural fortress for young marine species and a bulwark against storm surges that are becoming increasingly destructive as the atmosphere warms.
In the Philippines, where aquaculture has claimed more than half of the country’s mangroves in recent decades, the human benefits of coastal ecosystems were laid bare when Typhoon Haiyan tore into the eastern part of the archipelago. People living near healthy mangroves found the forests buffered some of the storm surge that devastated other areas like unprotected Tacloban. It was a rude awakening for the Philippines.
“That’s more powerful than any cost-benefit analysis,” says Conservation International’s Pidgeon. Since the 2013 disaster, the Philippines has begun returning fishponds and shrimp farms to banks of blue carbon.
Tropical nations around the world could benefit from this kind of conservation, Pidgeon and Herr, and many have taken note. Indonesia, which is home to as much as a quarter of all the world’s mangroves and seagrass ecosystems, just announced an international partnership for blue carbon solutions with Australia and Costa Rica.
Together with environmental groups IUCN, Conservation International, and UNESCO-Intergovernmental Oceanographic Commission, the group has pledged to publish a “roadmap” for coastal ecosystem conservation around the world.
They made the announcement earlier this month during the climate talks in Paris, just days before officials representing 196 nations signed on to an international agreement that affirmed “the role of conservation, sustainable management of forests and the enhancement of forest carbon sinks in developing countries.” More than $5 billion has already been promised to these efforts.
The Paris agreement repeated the goal of keeping global warming below 2 degrees Celsius of average global temperature rise by the year 2100. Conservation International thinks the world could get about a third of the way there just by restoring ecosystems, and blue carbon is a critical part of that plan.
“It is relatively simple if done right,” says Pidgeon. Despite fierce competition for coastal real estate, she says, resilient wetlands and mangroves are more than just passive sinks for greenhouse gases. They’re also natural seawalls, productive fisheries and ramparts against erosion.
“Nature is our ally,” says Herr.
