• In rebuilding an ecosystem, a Conservation International project showed that ‘everything is connected.’

When one small town saw its livelihood drying up, it had a choice: find new ways to make money, or overcome its fears and enlist an unlikely ally.

Crocodiles.

About a decade ago, the small fishing community of Topón in southern Mexico noticed that the shrimp on which its economy depended were dying off.

The community suspected that climate change, increased deforestation and overfishing had pushed the ecosystem too far — a suspicion since confirmed by scientists.

An artisanal fisherman from Topón. The community has experienced a dramatic drop in shrimp due to deforestation. © Flores

In the past, the community saw crocodiles as pests at best — threats, at worst. But a years-long project from Conservation International, the Global Environment Facility and the Mexican government has helped change that mindset — and show that conservation works best when it considers the entire ecosystem.

“Ecosystems are a complex and interconnected whole,” said Gustavo Garduño, project specialist at Conservation International-Mexico. “When one part gets out of balance, it can have a domino effect. Such is the case with crocodiles and shrimp.” 

For Topón, that ecosystem starts high in the Sierra Madre de Chiapas mountain range, where water flows steadily through the Pijijiapan River before spilling into the Pacific Ocean. But just before that, in the brackish waters of the estuary, is where the shrimp that sustain Topón live alongside an abundance of life.

Roseate spoonbills are one of many species that make this region one of the most biodiverse areas of Mexico. © Flores

Vibrant roseate spoonbills wade through the shallows to find fish. Reclusive crocodiles and caimans bask in the sun. And towering mangroves — the largest in North America — provide refuge for migratory birds, spider monkeys, jaguars and more.

Yet deforestation upstream has transformed the estuary. With the trees no longer there to act as a buffer, sediment flows freely, clogging waterways and causing the estuary's oxygen levels to plummet.

The shrimp were effectively being choked out, Garduño said.

“It’s a vicious circle,” he added. “While deforestation hurts shrimp populations, it is driven by falling incomes for fishermen who are catching fewer shrimp and instead turning to environmentally damaging, but more profitable, activities like cattle ranching and palm oil production.” 

Chiapas — where Topón is located — is the poorest state in Mexico, and with little control over deforestation upstream, the community needed to take a different approach to cleaning up the estuary’s water and making shrimping profitable again.

Young fishermen monitor crocodile populations © Flores

That's where the crocodiles come in.

Crocodiles are wetlands engineers, said Ramón Flores, coastal manager at Conservation International-Mexico.

When they swim through the water, their movements stir up sediment that has settled at the bottom. This action aerates the water, improving oxygen levels, and keeping minerals and nutrients from settling and clogging the system.

“Without the crocodile, the wetland ceases to exist,” Flores said. “If you want good fishing, crocodiles must be present — their decline is one of the main reasons that shrimp numbers have plummeted. Everything is connected.” 

But crocodiles’ role in the ecosystem was misunderstood — and fishermen would hunt the endangered species.

“We were very afraid of them and fear made us act against the animal,” said Mario Becerra, a founder of the Topón fishing collective. “There was hunger and there was need. Some killed it, and they’d say, 'We’re doing something good because we’re killing the crocodile, and we get to eat it too.'”

To change this perception, the project hosted workshops that showed the critical role crocodiles play in keeping the ecosystem healthy — and ensuring there is an abundance of shrimp to fish. They also organized monitoring brigades to keep an eye on the species and measure progress — an eye-opening experience for the community, Flores said.

“When the community joined in monitoring the crocodiles, they realized there weren’t many left,” he said. “Before, the community typically only encountered them in threatening situations. But witnessing the crocodile’s life cycle — from eggs to hatchlings to adults — play out in front of them had a profound and moving effect. Knowledge is power.”

While it is too early to know how the project has impacted crocodile populations in the estuary, Becerra said it has already transformed the community's relationship with the animal and helped them learn to coexist with it.

A river crocodile carrying its young in its mouth is captured on a camera trap that monitors crocodile populations.

As for shrimp, the fishermen’s catch has increased tenfold since the project began more than five years ago — though hasn’t yet returned to the yields seen a decade ago. The local economy is also showing signs of improvement, notably for women and youth. With a new shrimp processing plant, the fishermen hope to connect directly to higher-value markets that support sustainable production. 

“None of this would have been possible without taking this holistic and community-driven approach,” Flores said. “These are essential pieces to long-term sustainability.”

One of the most underrepresented groups within a community is children, he added, and Topón was no different: Many of the children there had never seen where their parents fished. So the project organized an environmental festival where each child received a pair of binoculars and bird guides to see the wildlife firsthand, and participate in lessons and activities about the local ecology.

“It was an amazing experience for the children and a powerful lesson,” Flores said. “If you want to achieve lasting conservation, you must involve people from an early age and establish that link between a community and the nature surrounding it.”

Children participate in activities like drawing contests and puppet theater focused on the surrounding environment. © Flores

Mary Kate McCoy is a staff writer at Conservation International. Want to read more stories like this? Sign up for email updates. Also, please consider supporting our critical work.