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
KHz PIT-tag Detector Front View Rear View Detection Tunnels Weight 650 lbs. About 4-ft cube
134.2 kHz, 2000 “Funnel Tests” Test tape configuration
Small trawl and electronics
2-coil antenna used 2001-present
Test tape pass location 3 April cm from antenna wall Coil 00: 98% Coil 01: 98% 20 cm from antenna wall Coil 00: 98% Coil 01: 98% Centered in antenna Coil 00: 32% Coil 01: 58% Centered in antenna Coil 00: 32% Coil 01: 58%
Large Trawl Whit Patten-style Electronics Master/Slave configuration
Weak-sister chart Master slave effect
Ryan, B. A., J. W. Ferguson, R. D. Ledgerwood, and E. P. Nunnallee 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: ).
4-coil flat-plate antenna 4 transceivers mounted in the jeep Bird colony detections
Density grid of test tags
“Sand Flea” Mechanical PIT-tag harvester (1998) Idea: Evaluate recovery of PIT- tags “missed” by the jeep system. Woops.
Crescent Island “Mechanical Verification”
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