Donn L. Park’s research while affiliated with National Marine Fisheries Service and other places

In 1985, two independent passive integrated transponder (PIT) tag monitoring systems were installed at the exit area of the weir leading into a fish trap on the north-shore fish ladder at Bonneville Dam, Columbia River. One hundred PIT-tagged adult steelhead Oncorhynchus mykiss were released in groups of 10 into an enclosed area of the ladder downstream from the detectors. The tagged fish were detected after they volitionally swam through the weir and slid through the detection system at velocities of 0.6 m/s or greater. Overall PIT tag reading efficiency was 98% and no tag-reading errors were recorded. Individual tag code, date, and time of the passage of each tagged fish were automatically recorded into a computer file and simultaneously printed onto a paper copy. These results suggest that PIT tag monitors of this design could be deployed at select adult passage facilities presently operating in the Columbia River Basin to interrogate returning PIT-tagged adult salmonids.