Monday March 16, 2009
The recent winter storms have increased salmon and steelhead movement throughout the Central Valley, resulting in increased catches of downstream migrating fish in rotary screw-traps. A few captured rainbow trout/steelhead are measured, weighed, photographed, and surgically implanted with tags to track their migration characteristics. Stream-width magnetic antennas are used to automatically detect and record tagged fish throughout the stream. The surgically implanted Oregon RFID 1/2 duplex tags track fish migration characteristics for the life of the fish, whether they remain in freshwater or travel to the ocean and return a few years later. The small tag size, low mortality rate, and value of information learned makes surgical tag insertion an acceptable technique to study wild fish.