Report on illegal fishing inside North America’s largest marine protected area spurs Mexican government action

15 Dec 2025

In early April 2025, Mongabay Latam published a Spanish-language investigation into suspicious fishing activity inside Mexico’s Revillagigedo National Park, the largest marine reserve in North America and a UNESCO World Heritage site. The report revealed that a U.S.-flagged sportfishing vessel had been detected operating inside the strictly protected area, where all fishing has been banned since 2017.

According to scientists, the boat had repeatedly entered Revillagigedo since 2012, years before it was declared a national park. On January 29, crew members of the boat posted photos on social media showing them catching yellowfin tuna, with dates that coincided with the vessel’s incursion into the park. Illegal fishing by sport boats in the area is not new, yet Mexican authorities had so far reported no sanctions on such operators.

Mongabay’s coverage drew on satellite data and expert analysis from scientists at the Centro para la Biodiversidad Marina y la Conservación (CBMC), a research group in La Paz, and the Scripps Institution of Oceanography near San Diego. Their teams documented incursions in January and March 2025, using both Skylight and Global Fishing Watch, tools that track vessel movements at sea in near real time.

According to their findings, the boat switched off its Automatic Identification System (AIS) — a satellite- and VHF-based tracking system commonly used by ships — upon entering the park, in a maneuver often linked to illegal fishing. The vessel only reappeared in AIS logs days later, once the boat’s system was turned back on. The investigation further revealed that this was not an isolated incident: other unidentified vessels without AIS signals were also observed operating in the area.

All types of fishing have been prohibited within the Revillagigedo marine reserve since November 2017. Photo courtesy of Ramiro Arcos.
All types of fishing have been prohibited within the Revillagigedo marine reserve since November 2017. Photo courtesy of Ramiro Arcos.

Researchers emphasized that all kinds of fishing, even sportfishing, pose risks to marine reserves, the latter particularly because of the tendency to target top predators like tuna and wahoo in places like Revillagigedo. “The ecological consequences are enormous because even though it’s sport fishing, they go after big fish because they want them as trophies,” said Fabio Favoretto, a postdoctoral researcher at Scripps.

Impact

Following the feature’s publication, Mexico’s National Commission of Protected Natural Areas (CONANP) formally reported the vessel at the center of Mongabay’s coverage for “suspected illegal fishing.” In an official statement released in April 2025, CONANP said that they had informed the Federal Attorney General’s Office for Environmental Protection (PROFEPA), which confirmed the information and stated that communication had been established with U.S. authorities to investigate the vessel in question. Mariana Boy, the head of PROFEPA, affirmed that the Secretary of the Navy and CONANP are also participating in these efforts and would evaluate the next actions to be taken.

The case highlights the importance of investigative environmental journalism in exposing illegal activity in protected areas. By bringing evidence of incursions into conservation zones like this to light, Mongabay Latam’s coverage not only documented long-standing threats to Revillagigedo’s biodiversity but also spurred official action to protect one of the planet’s most significant marine reserves.

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Banner image: One of the vessels allegedly engaged in illegal fishing inside the Revillagigedo marine reserve in January and March 2025. Photo courtesy of Red Rooster III.