Migratory Shorebirds Losing Ground in Mexico

By Diane Jukofsky and Katiana Murillo

CULIACAN, Sinaloa, Mexico, October 18, 2002 (ENS) - As the weather cools up and down the northern Pacific Coast of the United States and Canada, millions of shorebirds take to the skies and head south, some as far as Argentina. At least half will stop in Santa María Bay, on the northwest coast of Sinaloa state, on the Gulf of California.

The lagoons 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.

Santa María Bay (Photo courtesy Los Cabos Guide)

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 in the shorebirds themselves. Corven notes, "The 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, only over a longer period of time."

As part of 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 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 water, using hydraulic engineering and replanting mangrove trees.

WHSRN's and Pronatura's activities have the support of Mexico's Secretariat of the Environment and Natural Resources (SEMARNAT). José Dominguez, delegate of SEMARNAT in Sinaloa state, acknowledges that there is 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 channelization of natural canals.

"We recognize that there is a big problem in complying with environmental regulations in private and some public projects," Dominguez admits.

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 migration for themselves.

Another goal is to get the area declared an official Ramsar Site, a designation given to wetlands of international importance under the Convention on Wetlands known as the Ramsar Convention for the place where it was signed, Ramsar, Iran. In spite of its value to millions of migratory birds and other wildlife, Santa María Bay has no federal or state protection.

{Published in cooperation with the Rainforest Alliance.}