Earth Protect Blog

By MarÍa Verza, Christina Larson and Victoria Milko The Associated Press

PROGRESO, MEXICO » When a rotten egg smell rises from the mangrove swamps of southeast Mexico, something is going well. It means that this key coastal habitat for blunting hurricane impacts has recovered and is capturing carbon dioxide — the main ingredient of global warming.

While world leaders seek ways to stop the climate crisis at a United Nations conference in Scotland this month, one front in the battle to save the planet’s mangroves is thousands of miles away on Mexico’s Yucatan Peninsula.

Decades ago, mangroves lined these shores, but today there are only thin green bands of trees beside the sea, interrupted by urbanized areas and reddish segments killed by too much salt and by dead branches poking from the water.

A few dozen fishermen and women villagers have made building on what’s left of the mangroves part of their lives. Their work is supported by academics and donations to environmental groups, and government funds help train villagers to organize their efforts.

The first time they came to the swamp for seasonal restoration work was more than a decade ago with Jorge Alfredo Herrera, a researcher at the Center for Research and Advanced Studies of the Mexican Polytechnic Institute in Yucatan. He told them the mangroves needed a network of interlaced canals where fresh and salt water would mingle.

Digging them was hard work and paid only $4 a day. Men from Chelem, a fishing village of Progreso, turned down the job but a group of women took it on.

Recently, after an intense rainy season, the women worked to finish the second part of the restoration process: planting young mangroves in a swamp near this port city.

Then they placed 20-inch mangrove seedlings into mounds of mud held together by mesh, creating tiny islands about a yard square.

“The happiest day is when our plants take,” said 41-year-old Keila Vázquez, leader of the women who now are paid $15 a day and take pride in putting their “grain of sand” into the planet’s well-being. “They are like our children.”

Global threat

This mangrove restoration effort is similar to others around the globe, as scientists and community groups increasingly recognize the need to protect and bring back the forests to store carbon and buffer coastlines from climate-driven extreme weather, including more intense hurricanes and storm surges. Other restorations are underway in Indonesia, which contains the world’s largest tracts of mangrove habitat, Colombia and elsewhere.

“Mangroves represent a very important ecosystem to fight climate change,” said Octavio Aburto, a marine biologist at Scripps Institution of Oceanography in San Diego.

While the tropical trees only grow on less than 1% of the Earth’s land, he said, “on a perhectare basis, mangroves are the ecosystem that sequesters the most carbon ... They can bury around five times more carbon in the sediment than a tropical rain forest.”

Yet around the globe, mangroves are threatened.

From 1980 to 2005, 20% to 35% of the world’s mangrove forests were lost, according to the U.N. Food and Agriculture Organization.

From 2000 to 2016, the rate of loss declined as governments and environmental groups spotlighted the problem, but destruction continued — and about 2% of the world’s remaining mangrove forests disappeared, according to NASA satellite imagery.

In Mexico, as in much of the world, the largest threat to mangroves is development. The region near Cancun lost most of its historic mangroves to highways and hotels starting in the 1980s.

But in the past six years, Mexico has cut resources for environmental conservation by 60%, said Julia Carabias, a professor on the science faculty at the National Autonomous University of Mexico.

That, combined with increasing government support of fossil fuel energy and ongoing infrastructure and tourist projects in the region, is sounding alarms.

Efforts to save swamps

The halting efforts in Mexico to protect and restore mangroves, even as more are lost, mirror situations elsewhere. The U.N. Food and Agriculture Agency estimated in 2007 that 40% of Indonesia’s mangroves had been cut down for aquaculture projects and coastal development in the previous three decades.

But there have been restoration efforts as well. In 2020, the Indonesia government set an ambitious target of planting mangroves on 1.5 million acres of degrading coastline by 2024.

Yet there have been some setbacks. Precise mapping and data on mangroves is hard to come by, making it difficult for agencies to know where to concentrate. Newly planted mangroves have been swept out to sea by strong tides and waves. Community outreach and education have been slowed by the COVID-19 pandemic.