Installation and Development of Methods and Analyses for PIT Tag Antennas

the effects of management actions and ultimately lead to decisions on whether the fish can be recovered and/or delisted. Accurately detecting fish moving through rivers and streams is difficult and costly. Existing passive systems are primarily effective for species with predictable movement patterns that can be funneled past stationary antennas. Some systems exist for detecting fish in smaller tributaries or creeks, but these systems are limited in their ability to read fish in a larger river system. Endangered fish in the Colorado River Basin are tagged prior to stocking, or are captured using electrofishing or traps and tagged with PIT tags to allow researchers to track their movements and assess survival. Efforts to collect data on subsequent recaptures of the tagged fish involve large amounts of personnel and equipment since the fish must be physically recaptured to scan the PIT tags. Recapturing can lead to mortality or changes in behavior and movements and thus bias the data and place the endangered fish at risk. Remote and unmanned detection systems are needed to detect these fish without capturing to reduce both cost and injuries to the fish. In an effort to develop mobile and remote-detection systems, Reclamation and Utah State University researchers have collaborated on the development of several systems to detect fish as they pass through or under various antenna arrays. These systems were developed under a previous Cooperative Agreement through the Cooperative Ecosystems Studies Unit (CESU) agreement. These systems consist of antenna modules, a master controller to operate the antennas, various power supplies (solar and conventional 110volt AC), integrated Global Positioning System (GPS) equipment and software for mobile systems; and data recorders to record tag numbers, dates, times, and locations of tags in the various rivers. Some of the systems can be mounted to various watercrafts (e.g., rafts) and floated down a river.