STFA/CFMC Pilot Trap Vent Study
Progress Report(8/1/2008)
Completed TripsTrips/Fisherman
02468
101214
Blanchard Ledee Magras Quetel
Fisherman
Tra
p H
auls
Trap Hauls/Fisherman
0
10
20
30
40
50
Blanchard Ledee Magras Quetel
Fisherman
Tra
p H
au
ls
2 by 4 1 by 41 by 6 Control
Completed Trap Hauls
Total Fish (all traps)Total Fish
0
100
200
300
400
500
600
1 by 4 1 by 6 2 by 4 Control
Trap Vent Size
# F
ish
Catch/Trap Haul
Fish/TrapHaul
0.000.501.001.502.002.503.003.504.00
1 by 4 1by 6 2 by 4 Control
Vent Size
Fish
Total Fish in LandingsTotal Fish in Landings
0
100
200
300
400
500
1 by 4 1 by 6 2 by 4 Control
Trap Vent Size
# F
ish
Total Fish in BycatchTotal Fish in ByCatch
0
50
100
150
200
1 by 4 1 by 6 2 by 4 Control
Trap Vent Size
# F
ish
% Bycatch% Bycatch
0%
10%
20%
30%
40%
50%
1 by 4 1 by 6 2 by 4 Control
Trap Vent Size
# F
ish
Empty
Empty Traps# Empty Traps
0102030405060708090
1 by 4 1 by 6 2 by 4 Control
Trap Vent Size
# F
ish
Reasons for Discard
Reasons for Discard
0%
20%
40%
60%
80%
100%
1 by 4 1 by 6 2 by 4 Control
Vent Type
%
Regulatory
Non Comercial
Ciguatera
Too Small
Average FL in Bycatch
Average FL in ByCatch
188189190191192193194195196197
1 by 4 1 by 6 2 by 4 Control
Trap Vent Size
# F
ish
Average Length
150170190210230250270290310330350
Species
Leng
th (m
m)
Control 1 by 41 by 6 2 by 4
Average Lengths
Only 1 Doctorfish in 2 x 4
Blue Tang(Retained, FL)
Control
01234
5678
Fork Length (mm)
#
1 by 4 Trap Vent
0
2
4
6
8
10
12
14
Fork Length (mm)
#
1 by 6 Trap Vent
0
2
4
6
8
10
12
Fork Length (mm)
#
2 by 4 Trap Vent
0
0.2
0.4
0.6
0.8
1
1.2
Fork Length (mm)
#
Queen Triggerfish (Retained FL)
Control
0
2
4
6
8
10
12
150
180
210
240
270
300
330
360
390
420
450
480
Fork Length (mm)
#
1 by 4 Trap Vent
0
2
4
6
8
10
12
150
180
210
240
270
300
330
360
390
420
450
480
Fork Length (mm)
#
1 by 6 Trap Vent
0
1
2
3
4
5
6
150
180
210
240
270
300
330
360
390
420
450
480
Fork Length (mm)
#
2 by 4 Trap Vent
0
1
2
3
4
5
150
180
210
240
270
300
330
360
390
420
450
480
Fork Length (mm)
#
Preliminary Findings
1. Study design works well.
2. Escape vents release fish but also release target fish (2 x 4).
3. Other vents do not differ from controls.
4. Need to test other vents in order to find a successful design.
Vent Design Considerations• Location. Currently all of the vents in the pilot
study are located in the lower portion of the back panel of the trap (down as the trap is being hauled).
• Visual cues. All of the vents in the present study were created by removing portions of the mesh. There are no collars around the vents and some of the fishermen feel that the current one inch wide vents might work if there was a visual cue.
• Size. There is a general consensus that the 1 by 6 vent, or some modification of that vent size might be likely to improve escapement of by catch and the likely starting design will be some version of the 1 by 6 vent size.
• Orientation. Escapement may be enhanced by either horizontal or vertical orientation of the vents.
STFA CRP Proposal1. Goal: Design vents that will release target
species and still retain landings2. 18 Month study period3. 8 Fishermen: to rotate among interested
participants4. Phase 1 Vents to be developed from pilot
study findings5. Phase 2 Vents to be developed from Phase
1 findings6. Implement within STFA (46% of STT Trips)
as soon as developed (i.e. Don’t have to wait for FMP amendment or compatible regulations