SPECIAL SYMPOSIUM ON THE BIOTA OF CUATRO CIENEGAS:
JAMES E. JOHNSON
U.S. Fish and Wildlife Service
Albuquerque, New Mexico 87103
Scientists from the United States and México have in this symposium brought their specialties to bear on a single geographic area-a small valley in the Chihuahuan Desert of northcentral México called Cuatro Ciénegas (Four Marshes). One fact is clear from collective efforts of these distinguished researchers-Cuatro Ciénegas is an unique area and is of an importance that greatly exceeds its size. Zoologists and botanists, aquatic and terrestrial biologists alike agree that the Cuatro Ciénegas region is a special place; a place from which at least 56 endemic organisms already are described; a place helping us to understand speciation, niche segregation, character displacement, and biogeographic relationships; to use W. L. Minckley's term, "a living laboratory."
Several individuals were invited to participate in this symposium because of their past work in Cuatro Ciénegas. Each participant discussed his special area of expertise (plants, crustaceans, molluscs, reptiles and amphibians, fishes, birds, parasites), usually talking about uniqueness, but then coming to similar, broader conclusions. C. J. McCoy's and D. J. Pinkava's papers imparted a feeling of biological richness to the Valley; a mixing of organisms from Chihuahuan and Tamaulipan zones, of reliction perpetuated by the Valley's high mountains and narrow passes. G.A. Cole's crustacean paper provided a similar feeling over much broader geographic and time scales, indicating the mixing of Continental faunas during earlier geologic times. W. L. Minckley and R. Hershler represent first and second generation biologists studying Cuatro Ciénegas. Minckley is the acknowledged "Dean" of Cuatro Ciénegas biology and again demonstrated his in-depth knowledge of the basin in general, and specifically of its fishes and the fragile nature of its aquatic ecosystems. Hershler built upon earlier taxonomic work of D. W. Taylor, expanding and refining information on the Valley's remarkable molluscan fauna. Papers by G. Guajardo-Martínez (parasites) and A. Contreras-Balderas (birds) became available after the symposium; inclusion in these proceedings further broaden our knowledge of the Cuatro Ciénegas biota.
Salvador Contreras-Balderas concluded the seminar with examples of recent environmental impacts in the Valley. Contreras was asked to step from his usual role as one of México's leading ichthyologists in order to emphasize an underlying fear of all participants-the possible loss of Cuatro Ciénegas as a natural ecosystem.
Environmental changes are widespread in both the United States and México, threatening many habitats and the species dependent upon them, as demonstrated by the growing list of species needing protection. Most North American centers of endemism (Great Lakes, Ash Meadows/Death Valley, Colorado River) have been greatly modified by expanding needs and demands of human populations, resulting in loss of or decline in endemic biotas. Cuatro Ciénegas has emerged as one of North America's most important centers of endemism and is clearly the least modified to date. It also may be one of the most easily changed of these important biological areas. The very survival of Cuatro Ciénegas as an unique habitat may be decided within the next decade.
The purpose of this special seminar on the biota of Cuatro Ciénegas was to demonstrate importance of this small valley to the Mexican Federal Government and other State and Local entities that may consider and support its protection. The symposium was not an attempt by biologists from one country to tell officials from another how to handle internal affairs. United States' scientists are painfully aware of their country's mixed successes in protecting its own biological treasures. Rather, it was a sincere attempt by scientists from both countries to call attention to what they believe to be one of North America's most unique biological areas, an area so important that it might be called a Continental treasure, and an area so fragile that it could be lost before its values are fully understood.