Mexico’s federal environmental prosecutor freed 19 California sea lions from fishing nets embedded in their bodies during a June 2 operation across six rookery islands in the Gulf of California off Baja California. The rescue, carried out by PROFEPA (Mexico’s federal environmental enforcement agency), targeted mostly juvenile animals tangled in gill nets, a type of mesh barrier used widely by commercial fishers in the region. Ten males and nine females were brought aboard vessels, sedated remotely, and treated before release.
The operation is the latest in a recurring pattern of wildlife entanglement tied to what marine scientists call “ghost gear,” the lost, abandoned, or discarded fishing nets that drift through the Gulf of California for months or years after they stop catching fish for anyone.
Ghost Gear Kills Thousands of Marine Animals in the Gulf Each Year
The Gulf of California, also known as the Sea of Cortez, is home to roughly 30,000 California sea lions spread across more than a dozen major rookeries on islands between Baja California and the Mexican mainland. UNESCO designated the Islands and Protected Areas of the Gulf of California as a World Heritage Site in 2005, citing the region’s extraordinary marine biodiversity. Yet the same waters support one of Mexico’s most productive commercial fishing zones, and the two uses collide constantly.
Gill nets are the primary culprit. These vertical walls of monofilament or nylon mesh are designed to snare fish by their gills, but they trap sea lions, sea turtles, dolphins, and the critically endangered vaquita porpoise with equal efficiency. A 2020 study published in the journal Marine Pollution Bulletin estimated that more than 640,000 metric tons of ghost gear enter the world’s oceans annually. The Gulf of California is a particular hotspot because of the density of small-scale fishing operations, known as pangas, that use gill nets from open boats.
PROFEPA has legal authority to confiscate illegal nets and sanction fishers, but enforcement resources are thin. The agency oversees environmental compliance across all of Mexico, and its marine inspection teams cover a gulf stretching more than 1,100 kilometers from the Colorado River delta to Cabo San Lucas. A 2023 audit by Mexico’s Superior Audit Office found that PROFEPA’s budget had declined by 35% in real terms since 2018, limiting the agency’s capacity for patrols and inspections.
Conservation groups have stepped in to fill gaps. The Sea Shepherd Conservation Society has operated net-removal campaigns in the upper Gulf since 2015, pulling thousands of illegal nets from vaquita habitat near San Felipe. The organization reported removing more than 900 nets and other pieces of ghost gear during its 2024 campaign alone. Grupo Tortuguero, a binational network of fishing cooperatives and biologists, runs entanglement monitoring programs along both coasts of the peninsula.
Juvenile Sea Lions Face the Highest Risk of Entanglement
The fact that most of the 19 rescued animals were juveniles fits a well-documented pattern. Young sea lions are curious and inexperienced, making them more likely to swim into floating net fragments. Once tangled, the netting cuts into their skin as they grow, causing infection, restricted movement, and slow starvation. Researchers at the Universidad Autónoma de Baja California in Ensenada have documented entanglement scarring in up to 8% of juvenile sea lions surveyed at certain Gulf rookeries.
PROFEPA’s teams used “remote sedation” during the June 2 operation, firing tranquilizer darts to relax the animals before handlers removed netting that had become embedded in flesh. The technique allows rescuers to work without physically restraining a panicked animal, reducing injury risk for both the sea lion and the crew. Each animal was examined, treated, and released at the rookery where it was found.
The six rookery sites visited during the operation were not named in PROFEPA’s report, but the Gulf’s major sea lion colonies include Isla San Jorge near Puerto Peñasco, Isla Ángel de la Guarda, Isla San Pedro Mártir, and Los Islotes near La Paz. Los Islotes is one of the most visited snorkeling and diving sites in Baja California Sur, drawing tens of thousands of tourists each year who swim alongside the resident colony.
Fishing Cooperatives Hold the Key to Reducing Net Loss
Mexico’s small-scale fishing sector operates largely through cooperatives, or cooperativas pesqueras, that hold federal permits for specific species and zones. Some cooperatives in the Gulf have adopted net-marking programs that allow lost gear to be traced back to its owner, creating accountability. The cooperative at Bahía de los Ángeles, for example, has partnered with the nonprofit Pronatura Noroeste on a gear-tracking and beach cleanup initiative since 2019.
But compliance is uneven. Many fishers in the upper Gulf continue to use gill nets illegally, particularly those targeting shrimp and corvina. A 2024 report by the Environmental Defense Fund Mexico found that fewer than 40% of cooperatives in the Gulf had adopted any form of gear-marking or lost-net reporting. The report recommended tying fishing permit renewals to proof of responsible gear management.
PROFEPA stated that the June 2 rescue was part of its ongoing monitoring program for protected species in the Gulf islands. The agency has not announced a date for its next entanglement survey. This story was first reported by Ensenada.net, based on reporting by Elizabeth Vargas.