Desalting efforts under investigation.

• Position: Wetlands - Yuma Desalting Plant

A binational team is studying whether running the Yuma Desalting Plant will affect Mexico's Cienega de Santa Clara, the largest wetland on the Colorado River Delta. The cienega, a 15,000-acre wetland, is home to several endangered species and is a major stopover for birds migrating north and south along the Pacific Flyway.

"The plant will use U.S. agricultural runoff that would otherwise flow to this Mexican wetland," explains team leader Karl W. Flessa, director of the School of Earth and Environmental Sciences at the University of Arizona, Tucson. About 30% of the water now flowing into the cienega will be diverted into the plant for desalination. The plant's effluent, a smaller volume of much saltier water, will be returned to the canal that flows into the cienega.

The Mexican community of Ejido Johnson operates a small ecotourism business at the wetland. Birdwatchers are attracted by the species found there, including the Yuma Clapper Rail, listed as endangered by the U.S. and Mexico. "We've been monitoring the water level, water quality, bird populations, and vegetation in the cienega to find out if the operation of the Yuma Desaltlng Plant will affect the ecosystem," notes Flessa, who also is...