Over the past few decades, the harvesting of the Cortez oyster in western Mexico’s Marismas Nacionales — or the Marshes Biosphere Reserve — in Nayarit state has shifted from suffering from a fishing crisis to seeing a successful effort in its reintroduction and breeding in the ecosystem. This region, known to be one of Mexico’s richest and where the oysters are endemic, contributes to 45% of the country’s total fisheries production.

A fishing group dedicated to environmental conservation, the Ostricamichin Cooperative, has played a key role in protecting this important marsh in the Mexican Pacific Coast, which gained international recognition in 2001.

“Our job is to protect our environment. Farming has led us to refrain from exploiting natural resources and instead focus on repopulating the natural beds,” says Óscar Guadalupe Padilla Angulo, president of Ostricamichin.

The initiative started after a collaboration with the federal government in 1970 to enhance the farming of the Cortez oyster (Crassostrea corteziensis) by collecting wild “seeds” — or juvenile oysters — to grow them in floating rafts within the estuaries.

He says that the technique of deploying these floating rafts has been so effective that it has remained unchanged for nearly 55 years.

Marcos Moreno Torres, a fisher and member of the cooperative since it was first established, witnessed first-hand both the crisis and the revival of the Cortez oyster, a shellfish that his parents and grandparents used to collect by diving.

“There came a time when climate conditions and overexploitation caused a decline, and by 1975, the oysters had completely disappeared. We endured five years of oyster crisis,” says Moreno. “But in 1980, we saw a record production, and from that point on the project grew, ultimately saving the species.”

In 2023, the region recorded the highest oyster catch in the past 20 years, surpassing 5,000 tons annually, according to the latest data from the Mexican National Fishing Charter.

A cooperative in service of the community

For Heidy Zaith Orozco Fernández, president of the NGO Nuiwari Centre for Social Development and Sustainability, the significance of Ostricamichin’s work lies in its ability to develop a productive activity while strengthening the community of Santiago Ixcuintla town.

“Ostricamichin has been a leader in promoting initiatives that not only improve the quality of life for the community but also contribute to the conservation of the ecosystem,” she says.

Beyond the recovery of the Cortez oyster — now appearing in areas where fishers had never encountered it before — oyster farming has also helped restore other fish species in the Nayarit Marshes Biosphere Reserve. This protected area spans over 133,000 hectares (328,650 acres), stretching from northern Nayarit to southern Sinaloa state.

“When you focus on farming, you forget about fishing, and only [fish] for self-consumption. This allows species like the sea bass and the snapper to recover, as they are no longer overexploited,” says Angulo.

He also emphasizes that during the farming process, which lasts between 8 and 10 months, oysters are also harvested from natural beds that are no longer overexploited.

“In the months when there is nothing, we fish on the oysters’ natural banks. For example, each member collects between 25 and 50 kilograms [55 and 110 pounds] of oysters, and we distribute them carefully to avoid depletion and ensure that everyone benefits,” he says.

Moreno Torres adds that the cooperative carefully measures its production capacity to avoid extracting more than necessary.

“We are committed to not overexploiting nature. We set a limit to prevent oversupply and to maintain the system’s productive balance, even though our indicators suggest that the area could produce double or even triple the current amount,” he says.

Orozco Fernández highlights the cooperative’s strong environmental awareness, noting that oyster farming does not disrupt the marine ecosystem’s natural dynamics.

This is due to the raft cultivation technique, which allows the oysters to grow while also generating additional seeds that settle at the bottom of the estuary, promoting natural regeneration.

“Previously, [people] dived to harvest oysters, but that method focused solely on extraction rather than sustainability. Now, with oyster farming on rafts, the oysters can develop naturally, and they don’t have to modify the ecosystem,” he says.

Ostricamichin is currently one of the two certified cooperatives in Nayarit for the sanitary retrieval of mollusks. They also possess fish concessions for other marine species, such as sea bass, meagre (Argyrosomus regius), red porgy (Pagrus pagrus) and snook (Centropomus sp.).

The cooperative has more than 180 members and operates 500 oyster farming units or rafts, capable of producing 1,200 strings of oysters.

The cooperative’s president notes that, so far this farming season, they have produced more than 600 tons of oysters and aim to reach 800 tons — a significant recovery following the devastation of Hurricane Roslyn in 2022, which destroyed their rafts, damaged their oysters, and wiped out nearly 50% of their production.

Ostricamichin’s challenges

Still, the cooperative continues to face external challenges such as illegal fishing, climate change and the development of large-scale projects in the region.

Ostricamichin also dedicates efforts to protect the San Pedro Mezquital River — the only river in the region that flows freely without dams from the Sierra Madre Occidental mountains to the Pacific, where it merges with the national marshes.

In 2014, Mexico’s national electric utility, Federal Electricity Commission (CFE in Spanish), proposed the construction of a hydroelectric project, known as Las Cruces, within the river basin. This project would have severe consequences for nearby communities and the natural marshland reserve.

Although federal authorities declared the project canceled years ago, local citizens and activists report that the commission may be planning to reintroduce it under a new name: Presa del Nayar.

Mexican President Claudia Sheinbaum has confirmed that the dam project is still under review.

“Any dam project … it is not considered for 2025, to start it. These are some of the projects that Efraín Morales, the director of Conagua, is studying. But, in any case, first, it is already in the Constitution that there must be Indigenous consultation. And in case it is not an Indigenous population, we always have to reach an agreement with the community and the inhabitants,” she stated during a press conference on Dec. 4, 2024.

“As an organization and as a community, we are all committed to defending this land, and we don’t trust that the project has been completely abandoned,” says Moreno Torres of the dam. “We remain vigilant because we have too much to lose.”

Padilla Angulo says that, based on the experience with the Aguamilpa hydroelectric dam in Nayarit, a new project would bring serious negative consequences.

“Building a dam on this river would lead to the salinization of the entire salt marsh area, since the river is the main freshwater artery feeding the marshes,” he says. “We would lose the ability to set oyster seeds because this species depends on brackish water.”

Orozco Fernández also highlights the social impact on the Náyeri and Wixárika Indigenous communities in the region. “If this river is dammed, the entire mangrove system will collapse due to its already-accumulated environmental stress. But there’s also a spiritual impact — many sacred sites would be flooded,” she says. “Biologists, hydrologists and specialists agree that constructing this dam would be a death sentence for Marismas Nacionales and its mangroves, as they rely on the delicate balance between freshwater and saltwater. This would ultimately devastate aquaculture and fishing because oysters depend on the river’s natural water pulses.”

According to Moreno Torres, the consequences are clear — a dam in this region wouldn’t just mean the end of Ostricamichin but “the end of life.” In response, the community is already preparing to defend their land, their way of life, and their future.

 
Banner image: A Cortez oyster (Crassostrea corteziensis). Image courtesy of Jose Manuel Mazon-Suastegui via Wikimedia Commons (CC-BY-SA-4.0).

Small-scale fishers’ role in feeding the planet goes overlooked: Study

This story was first published here in Spanish on February 26, 2025.