To determine whether the endangered fish are responding to recovery actions, populations of the endangered fish must be monitored over time. Annual capture surveys using standardized electrofishing and netting techniques provide data with which fish densities or relative abundance can be calculated. Over a series of years, such capture indices can show whether the abundance of a given population is trending upwards or downwards.
Researchers from CRFP, New Mexico Game and Fish, Utah Division of Wildlife, FWS (Region 2) and Bureau of Indian Affairs conduct annual collaborative trips on the San Juan River to monitor endangered fish populations. Photo taken in 2006 downstream of Bluff, Utah by C. Hinds.
Annual fall seining of Colorado River backwaters was conducted from 1982 to 2000 to monitor annual production of wild Colorado pikeminnow. Netted fish are identified, counted and released. This 1988 photo by D. Osmundson was taken near Gold Bar downstream of Moab, Utah.
Biologists on the San Juan River tag fish as part of population monitoring studies. Photo by E. Teller.