Luther B. WayRichard D. Ledgerwood

Brad A. RyanAnd

April S. Cameron

Luther B. WayRichard D. Ledgerwood

Brad A. RyanAnd

April S. Cameron

IN-SITU VERIFICATION OF MOBILE PIT-TAG

DETECTION SYSTEMS--

Trawls and Birds

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

400 kHz detectors400 kHz detectors18” diameter,

1999

3-pipe bundle of 10” diameter,

1998

134.2 kHz, 2000“Funnel Tests”

134.2 kHz, 2000“Funnel Tests”

0 45

0 1 0

1 6 3

2 14 11

3 7 5

4 1 1

5 1 0

30 20 50

degrees

spacing

Test tape configuration

Test tape configuration

Small trawl and electronics

2-coil antenna used 2001-present2-coil antenna used 2001-present

Detection Rates of Pit-tagsAttached to a Test Tape, 2001

0

10

20

30

40

50

60

70

80

90

100

Spacing of Adjacent Tags (cm)

Det

ectio

n R

ate,

(%

)

0° 45°

30 61 91 122 152

508

71

1,324

612

921

278

130

59

35

28

Test tape pass location3 April 03

Test tape pass location3 April 03

20 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 TrawlWhit Patten-style Electronics

Large TrawlWhit Patten-style Electronics

Master/Slave configurationMaster/Slave configuration

Weak-sister chartWeak-sister chart

Master slave effectMaster slave effect

Master/Slave Comparison

0

20

40

60

80

100

Weak Master Strong Master

Det

ecte

d (%

)

Coil 00, n = 66 Coil 01, n = 114

Slave

Slave

Master

Master

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 antenna4-coil flat-plate antenna

4 transceivers

mounted in the jeep

Bird colony detections

Density grid of test tagsDensity grid of test tags

28 21

18 19 2027 22

26 2315 16 17

25 24

11 12 13 14

4 3

8 9 10

5 6 7

2 1

28 21

18 19 2027 22

26 2315 16 17

25 24

11 12 13 14

4 3

8 9 10

5 6 7

2 1

“Sand Flea”Mechanical PIT-tag harvester

(1998)

“Sand Flea”Mechanical PIT-tag harvester

(1998)

Idea: Evaluate recovery of PIT-tags “missed” by the jeep system. Woops.

Idea: Evaluate recovery of PIT-tags “missed” by the jeep system. Woops.

Crescent Island“Mechanical Verification”

Crescent Island“Mechanical Verification”

Post-Jeep Detections

817 525

15568

11842

0

4000

8000

12000

16000

20000

2001 2002

Detection Year

Tot

al T

ags

Biomark Detections Total 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

ConclusionsConclusions