Presentation on theme: "Luther B. Way Richard D. Ledgerwood Brad A. Ryan And April S. Cameron Luther B. Way Richard D. Ledgerwood Brad A. Ryan And April S. Cameron IN-SITU VERIFICATION."— Presentation transcript:
Luther B. Way Richard D. Ledgerwood Brad A. Ryan And April S. Cameron Luther B. Way Richard D. Ledgerwood Brad A. Ryan And April S. Cameron IN-SITU VERIFICATION OF MOBILE PIT-TAG DETECTION SYSTEMS -- Trawls and Birds
“Electric barge” Tow Vessels (91m between wings) Large Pair-trawl (freshwater) Ledgerwood, R. D. J. W. Ferguson, B. A. Ryan, E. M. Dawley, and E. P. Nunnallee. In press. A Surface Trawl to Detect Migrating Juvenile Salmonids Tagged with Passive Integrated Transponder tags. NAJFM
1996 400KHz PIT-tag Detector Front View Rear View Detection Tunnels Weight 650 lbs. About 4-ft cube
Ryan, B. A., J. W. Ferguson, R. D. Ledgerwood, and E. P. Nunnallee. 2001. Detection of passive integrated transponder tags from juvenile salmonids on piscivorus bird colonies in the Columbia River Basin. North American Journal of Fisheries Management (21:417-421).
4-coil flat-plate antenna 4 transceivers mounted in the jeep Bird colony detections
Needed is a way to regulate the rate at which the test tape is passed through the center of the detection antenna END On a pass-through detection system, the test tape needs to be passed through the center of the detection antenna Where the concentration of tags is great, as on bird nesting islands, inter-detector collisions need to be minimized by adjustments to the circuitry. All PIT-tag detection systems need a quantitative measurement of detection efficiency Conclusions