Night has fallen on the Sea of Cortez, and it’s so dark I can barely see my three companions, even though they’re just a few feet away. We’re camping on a sandy cove on the craggy western shore of Espíritu Santo Island, an uninhabited nature reserve near the southeastern end of Mexico’s Baja California peninsula. Tonight we have the entire island to ourselves, all 40 sere square miles of it. Eroded volcanic cliffs rise steeply behind us; small waves break gently on the beach -- above it all, a vault of stars. A perfect desert-island idyll; no one disturbs our solitude. And that’s not good.
"Every semester I come here to camp with my students," says Carlos Sánchez Ortiz, who is sitting on a plastic cooler, his feet stretched out in sand that’s still warm on this late August night. "Only once in 20 years has PROFEPA checked on us."
PROFEPA -- short for Procuraduría Federal de Protección al Ambiente -- is Mexico’s environmental protection agency; its conscientious but overstretched agents oversee the country’s national parks and other natural refuges. "They found us here one night last year and asked for our camping permits," says Sánchez Ortiz, a professor of marine biology at the Autonomous University of Baja California Sur in La Paz. "It was 11 o’clock, and I told them I was glad to see them, because this island needs protection. I asked them how many times they came here, and they told me once a week, or sometimes just once a month, because the funding from Mexico City had disappeared. If you look at a map of the Sea of Cortez, you’ll see that many natural areas are listed as protected. But there is almost no enforcement."
Espíritu Santo is but one of more than 900 islands in the Sea of Cortez. The sea itself -- also known as the Gulf of California -- extends some 750 miles, from the dried-up Colorado River delta in the north to the resort city of Cabo San Lucas at the southern tip of the Baja peninsula. During the past two decades the Mexican government has created 11 marine protected areas in the Sea of Cortez. The intention was to promote sustainable fishing practices: gill nets and trawling are banned, and a few small areas have been designated as no-take zones, where fishing is completely prohibited, at least in theory. In practice, the laws are largely ignored.
The Sea of Cortez is the world’s youngest sea, having formed 5.6 million years ago when part of the tectonic plate beneath the Pacific Ocean broke away from North America. It is one of the most biologically diverse bodies of water on earth. Jacques Cousteau, the famed French diver and ocean explorer, called it the world’s aquarium. Rare and spectacular marine mammals breed and feed here, including the largest animal that has ever existed -- the blue whale -- and the smallest member of the marine cetacean family and one of the most endangered, the four-foot-long vaquita, Phocoena sinus. Only 200 or so of these porpoises remain in the wild, all in the northern end of the Sea of Cortez. Nearly a thousand species of fish dwell here, and at least 5,000 invertebrate species -- no one knows the true number. Hundreds of bird species nest on the sea’s islands. Some biologists think that the region’s 6,000 recorded species might fall short of the actual total by as much as 30 percent.
For all that remarkable diversity, the Sea of Cortez is a sea in decline. Cousteau might also have called it Mexico’s fish market. Every year fishermen take more than 500,000 tons of seafood from the sea, representing about half of Mexico’s fishing economy. (The Gulf of Mexico and the Pacific account for the rest.) That annual catch counts only the fish brought to market; estimates of unwanted bycatch of fish and marine mammals range wildly, from one million tons to three million tons. The destruction began in the 1930s, when the arrival of outboard motors and gill nets transformed fishing here.
Shrimp trawlers do the most damage. For every pound of wild shrimp caught, trawlers kill as much as 40 pounds of bycatch. Using nets weighted with heavy chains that dig as much as a foot into the sea floor, the trawlers scrape virtually any seabed shallower than 300 feet, dredging the bottom year after year in a maritime version of clear-cutting. The wild shrimp fishery in the northern Sea of Cortez has virtually collapsed. In the last several decades, five species of sea turtle have all but disappeared from these waters.
Thousands of illegal vessels are in operation throughout the gulf, and poaching is common. Honest fishermen struggle to make a living, as I learn when two fishing boats pull up on the beach at Espíritu Santo just as we’re breaking camp on an overcast morning.
Five men arrive in the two pangas, high-bowed, narrow-beamed fiberglass boats popular with Sea of Cortez fishermen. They’re here seeking shelter from the rain that threatens to start at any moment. They’ve barely pulled their pangas onto the beach when the storm hits; warm sheets of rain send us all running for cover beneath a rock overhang at the base of a cliff.
While the rain merges with the sea, one of the men tells us that he’s been fishing in this area for 30 years, since he was a boy, and complains that he now needs a pocketful of permits to fish where he’s always fished. He obeys the law and avoids the protected areas, and as a result his catches are far smaller than they used to be. Before the protected areas were established, he would typically net more than 200 pounds of fish in a couple of days. Now it takes a week. In any case, he says, the protected areas are plagued by illegal fishing, which usually takes place at night. He tells us he knows many fishermen who break the law. Some of them are family members and neighbors. He would never report them, he says, because they’re just trying to make a living. The other four men agree.
Sánchez Ortiz confirms the fisherman’s assessment. Almost without exception, he says, the protected areas in the Sea of Cortez are not rebounding. For the past 14 years, he and his students have been making careful surveys of crucial habitats here, counting the number of species in selected areas almost yard by yard. The data are grim. Recovery efforts, hamstrung by lack of enforcement, have largely failed. "In almost all the Sea of Cortez, even where it is protected, the sizes and numbers of fish today are less than 10 years ago," he says.
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The Mercado Municipal bustles on a steamy August morning in La Paz. As electric fans whirl overhead and music blares from radios, dozens of workers chop and clean recently deceased denizens of the Sea of Cortez, prepping them for the day’s shoppers.
"You can trace the history of the sea in this market. It is one of the oldest in La Paz," Sánchez Ortiz tells me as we walk the market’s ocher tiled floors, passing green plastic bins filled with ice and fish. "Twenty years ago you would see mostly yellow snapper and leopard grouper. They are the best to eat. Now they sell more sand perch, tilefish, and others that used to be thrown back." And all the fish in the market are much smaller than they used to be -- the average length of caught fish has decreased by more than 17 inches in the past 20 years. As we pass a glistening display of yellow snappers, none exceeding a foot in length, Sánchez Ortiz pauses, spreads his hands about three feet apart, and says, "I used to see them this big."
The market is dominated by fish that wouldn’t have appeared on anyone’s plate 10 or 20 years ago. "You can see from looking at the fish here that we’re going deeper into the sea to catch them and fishing further down the food web," says Octavio Aburto Oropeza, a 39-year-old marine biologist at the Scripps Institution of Oceanography in San Diego. He is also an accomplished photographer, and has spent many hours underwater capturing images of exquisite beauty in the Sea of Cortez. A native of Mexico City, he came to La Paz in 1990 to study marine biology at the university here; at the time, it was the only campus in Mexico with a full-fledged program. He became one of Sánchez Ortiz’s students, and they still collaborate frequently. In 2009 they were part of a research team that conducted an extensive survey of the Sea of Cortez, documenting the effects of overfishing and habitat loss. Fish have completely disappeared from some reefs in the northern part of the sea. The absence of grazing fish may explain why bacteria now cover the reefs, a phenomenon referred to by one of the researchers as the rise of the slime.
For much of the past decade, Aburto Oropeza has been working with scientists in the United States and Mexico to identify habitats that are crucial for the long-term viability of fisheries in the Sea of Cortez. His research suggests a practical and economical conservation strategy: to save the sea, and the livelihoods of those who depend on its bounty, it might be enough to protect -- with effective enforcement -- a few key clearly defined areas.
Among those essential habitats are mangrove swamps. The Sea of Cortez marks the northernmost extent of mangroves on the Pacific side of the Americas. Mangroves thrive in shallow tidal lagoons, their stilt-like roots often permanently submerged. As a result of evaporation, tidal shallows can have higher salt concentrations than the sea itself. To survive in this arboricidal environment, mangroves have evolved some unique adaptations: their leaves exude excess salt crystals, and some species have snorkel roots, which grow up through the mud to obtain oxygen. At least a third of all the fish and shellfish caught by small-scale fishermen here spend part of their life cycle in the sheltering, rooty embrace of mangrove swamps. The trees also reduce coastal erosion and storm damage, although that fact seems to have been lost on the developers, cattle ranchers, and shrimp farmers who are cutting them down. (Farmed shrimp are typically raised in large rectangular pens, with networks of dikes. Mangroves are destroyed to make room for the pens and dikes, and to make the pens accessible.) Since the 1970s, parts of the Sea of Cortez have lost more than a quarter of their mangrove forests, and nationwide the rate of destruction has accelerated, with some 2 percent of the remaining mangroves across Mexico now being cleared each year.
This article was made possible by the Jonathan and Maxine Marshall Fund for Environmental Journalism.