Ecological Society of America, Tucson, AZ, August, 2002. Symposium: Every Last Drop: Ecology, Conservation, and Restoration of North American Springs Ecosystems.

Springs and desert fishes: their ecology, management, and restoration.

P.J. Unmack

Springs in the desert are often referred to as aquatic islands in a sea of desert. They are an excellent place to explore certain ecological and evolutionary processes. This is partially due to their low species richness, small size, and discrete boundaries. Most springs, especially in deserts, are relatively small, ranging in size from permanent damp spots a few square meters in area to some which rival a small stream. Most springs have unique physico-chemical characteristics relative to other aquatic habitats. Examples include constant discharge rates and temperatures with variation occurring along a gradient. Some springs exhibit harsh conditions including high temperatures and carbon dioxide levels as well as unusual chemistry. Springs are of immense importance to fishes and other aquatic animals. Many are endemic to one, or a few springs, and springs often represent the last remaining aquatic habitats due to aridity. Unfortunately, the future of many spring systems is grim, or less than ideal. Most have been modified and primarily managed to allow their water to be utilized for irrigation. While some management and restoration efforts have been undertaken, they are often piecemeal due to a lack of resources, usually reactive to an immediate problem, and not well evaluated to determine how management actions can be improved upon in the future. In this presentation I will outline a few ecological highlights among fishes, discuss some of the management actions undertaken, and overview restoration efforts.