A Remote Satellite-Linked Tracking System for Studying Pacific Salmon with Radio Telemetry

A remote tracking system with a satellite uplink was used to study the movements of adult Chinook salmon Oncorhynchus tshawytscha and coho salmon O. kisutch in the large, isolated Taku River in Alaska and British Columbia. Salmon were tagged with pulse-coded radio transmitters; 10 codes identified individual fish on each of 52 frequencies. Remote tracking stations automatically collected, processed, and transferred telemetry data via a computer-controlled receiver. A satellite uplink was used to retrieve the data for within-season analysis. Three hundred six Chinook salmon were tracked upriver in 1990 and 351 coho salmon in 1992. Coho salmon could not have been tracked with conventional methods due to the inclement fall weather and mountainous terrain typical of this area. The stations recorded 98–100% of the radio-tagged fish that moved past. Tracking success was much higher than in previous studies in which fish were tracked exclusively from aircraft. The remote tracking system is an effective method for precisely tracking large numbers of salmon in large, inaccessible rivers, and it has numerous applications to fisheries research.