Use of the Global Positioning System for Locating Radio-Tagged Fish from Aircraft

Abstract

Tracking from aircraft is a method commonly used to locate radio-tagged animals, and it typically involves observers who assign locations of detected animals in relation to physical landmarks. A technique that uses a Global Positioning System (GPS) receiver instead of observers was developed and tested during 1993 to identify locations of radio-tagged adult rainbow trout Oncorhynchus mykiss during aerial tracking in the Yakima River drainage in Washington. The technique was effective under both ideal and adverse weather conditions. Tracking flights that used the GPS receiver were more efficient, more accurate, safer, and less expensive than traditional tracking flights that require observers to estimate locations by using visual landmarks.