As the weather cools up and down the northern Pacific Coast of the United States and Canada, millions of shorebirds take to the skies. Shorebirds are long-distance migrants, and some will start in Alaska and go the distance — 10,000 miles south to Tierra de Fuego, Argentina. At least half will stop in Santa María Bay, on the northwest coast of Sinaloa state, on the Gulf of California. The lagoons, canals, and wetlands of Santa María can provide the birds with perfect wintering habitat — or for hundreds of thousands of them, water and fuel enough to continue their journey farther south. But in recent years, farming and aquaculture in Santa María has converted much of the area into an unsafe harbor for migratory shorebirds.
“During the migration, the skies over Santa María can be black with birds. On the ground they are shoulder-to-shoulder, birds as far as the eye can see,” says Jim Corven, director of the Western Hemisphere Shorebird Reserve Network (WHSRN) a U.S.-based coalition of more than 240 organizations in North and South America. The network is working with the local conservation group, Pronatura Northwest, communities, and the government of Mexico to try to rescue and restore Sinaloa’s wetlands.
According to Corven, high-tech horticulture is responsible for much of the wetlands destruction along the coast. The farmers are using drip irrigation, automated pesticide control, raised beds, and large quantities of fertilizers and pesticides. Drainpipes from the fields often empty directly into the wetlands. The tomatoes, green peppers, cucumbers, and other vegetables are exported to the United States.
Researchers with WHSRN are checking the pesticide levels in the water, mud, and the shorebirds themselves. Corven notes: “These sub-lethal effects of pesticides can be just as devastating as pesticide applications that may kill the birds outright. You don’t see the sub-lethal effects as readily, but it turns out they may be 10 times more deadly than acute effects, over a longer period of time.”
In a now-abandoned development scheme, ponds dug for shrimp farms destroyed thousands of acres of Santa María’s wetlands. In an experimental project funded by the North American Wetlands Conservation Act — a cooperative agreement among the United States, Canada, and Mexico — Pronatura and WHSRN scientists are attempting to reclaim some 24,700 acres (10,000 has) of abandoned shrimp farms, converting them back to fertile wetlands. According to Xico Vega, director of Pronatura Northwest, the groups will use aerial photographs of the area taken before the shrimp farm construction to guide them in an attempt to restore the natural flow of about 124 acres (50 has) in a pilot project, using hydraulic engineering and enriched mangrove planting.
“It’s likely that if we are able to restore the natural flow, the mangrove system would come back,” he explains, “but we want to plant mangrove trees as a way to accelerate recuperation and also provide jobs in the area.”
WHSRN’s and Pronatura’s activities have the support of Mexico’s Secretariat of the Environment and Natural Resources (SEMARNAT, for its name in Spanish). José Dominguez, delegate of SEMARNAT in Sinaloa state, acknowledges that there’s a good deal of pressure from horticultural activities in the region, along with other development projects that cause erosion, contamination, damming of natural waterways, and rechannelization of natural canals. “We recognize that there is a big problem in complying with environmental regulations in private and some public projects,” he says.
He adds that one of SEMARNAT’s priority goals in Sinaloa is to more closely regulate activities that have high environmental impacts, as well as to increase conservation and restoration activities throughout the state.
Vega emphasizes that environmental education is an integral part of the conservation project in Sinaloa. Children in local schools receive an introduction to the birds found in their watery backyard and the importance of the wetlands to the birds’ survival. They also take field trips to see the magnificent migration for themselves. Vega believes that the community has increasing respect for Pronatura’s work. He points to the case of a colony of terns, whose eggs were traditionally swiped by local residents who used them to soothe hangovers. With each nesting season, however, Vega finds fewer and fewer eggs disappear. “Definitely we have a change of attitudes with respect to the work we are doing,” he says.
Another goal of the groups’ work in Santa María is to get the area declared an official Ramsar Site, a designation given to wetlands of international importance. In spite of its biological importance, Santa María Bay has no federal or state protection, though it is a designated Hemispheric Site of the Western Hemisphere Shorebird Reserve Network (WHSRN). Corven points out that of the 50 species of shorebirds that breed in the United States and over-winter in the south, some 25 are in major decline, including the snowy plover (Charadrius alexandrinus), American avocet (Recurvirostra americana) and elegant tern (Sterna elegans). During the autumn and spring migrations and throughout the winter, all three are found in Sinaloa, which is also home to about one-half of Mexico’s more than 1,000 bird species.
— Diane Jukofsky and Katiana Murillo
Blvd. Culiacan #3771
Culiacan, Sinaloa, Mexico
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