Cover photograph: An image of the Yaqui Valley, Sonora, Mexico, which shows the valley's drainage into the Gulf of California. Effluent from agriculture and urban centers runs into the coastal waters, which are home to migratory and resident birds, marine mammals, and fish. Both agriculture and fishing are central components of the local economy, suggesting that disruption of one part of this economy would have deleterious effects on the entire economy. See article by Turner et al. on page 8080.