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Seabird Interactions on Alaskan Groundfish Trawl Vessels
Shannon M. FitzgeraldKim S. Dietrich
Alaska Fisheries Science Center
The Groundfish Trawl Fleet
Gear Types
Processing Modes
Catcher-Processor
Catcher Vessel
Mothership
Floating Processor
Shoreside Processor
Pelagic
Non-Pelagic (Bottom Trawl)
Target Species
Walleye Pollock,
Pacific Cod,
Atka Mackaral,
Rockfish,
Flatfish,
and others
0
500
1000
1500
2000
2500
3000
3500
19
93
19
94
19
95
19
96
19
97
19
98
19
99
20
00
20
01
20
02
20
03
20
04
20
05
20
06
20
07
20
08
20
09
20
10
S
Species/Species Group 2007 2008 2009 2010 2011 2012 2013 2014 2015
Laysan Albatross 9
Black-footed Albatross 60
Northern Fulmar 652 537 633 503 329 297 463 85 463
Shearwaters 726 13 41 155 3 56 1 72 62
Storm Petrels 1 44
Gulls 303 9 82 57 1 3
Kittiwakes 6
Murres 2 102 14 3 47
Auklets 3 4 66
Other Alcids 105
Cormorants 3
Other Birds 136
Unidentified Birds 16 44 3 6
Grand Total1,700 606 1,057 821 347 413 474 270 534
Table 7. Estimated seabird bycatch for Alaska groundfish trawl fisheries, pelagic and non-pelagic gear combined, all fishery management plan areas combined.
Third Wire
Trawl Warp
“Shortwiring”: Third Wire increased exposure
Net, “suitcase”
1993 - 2002 # Incidents #Birds
Laysan Albatross 12 24
Northern Fulmar 9 33
Gull 3 10
Shearwater 1 1
Unidentified Bird 3 >46
Location Years Catch rates Citation
Heard & Macdonald
Is.
1997-2000 2.1 birds/100 tows (Wienecke and Robertson
2002)
Falkland Islands 2002-03 0.47 birds/day (within EEZ);
3/day (outside EEZ)
(Sullivan et al. 2006b)
Argentina 2004-05 >14 birds/100 tows (Gonzalez-Zevallos et al. 2007)
South Africa 2004-2005 net mortality: 3.02/100 tows
warp mortality: 30/189.5 hrs
(Watkins et al. 2008)
Southern Ocean 2006/07
krill: 0 birds
icefish: 7 birds per 100 tows
toothfish/icefish: 1
bird/100tows
(CCAMLR Secretariat 2008)
New Zealand
2004/05
2005/06
2006/07
04-05: 6.24 birds/100 tows
05-06: 5.4 birds/100 tows
06-07: 2.68 birds/100 tows
(Abraham and Thompson
2009a)
Third-wire images
Top row is a catcher vessel
Bottom row is catcher processor
• EM could be an effective tool to monitor seabird interactions with trawl cables
• Daytime presence, relative abundance, and general seabird behavior
• Detected 3rd wire entanglements (but not the cause)
• Species identification sometimes possible, most mostly only to large groups
• EM would be very suitable for monitoring the use and effectiveness of mitigation measures
2006 Bycatch Reduction Engineering Program grant* to support development of mitigation
measures
* Federal employees can no longer directly apply for these funds
Third Wire Boom
• Tested “1st generation” mitigation gear for cables and warps• Vessel specifics affected cable strike rates• Showed that mitigation measures were promising
• As compared to S. Hemisphere approach to ban 3rd wires• OF NOTE
• On-board observers (standard sampling) detected 3 birds in 200 hauls• Dedicated seabird observers detected 17 birds in 170 of the same hauls
Concurrently: Observer Special Project
• 2004 – Pilot
• 2005-2006 full project
• (mitigation work in 2006-2007)
• 2009 repeated
• Standard sampling continues
• Supplemental sampling from monitoring haulback
Seabird Catch rate by Haulback observation code
Error bar indictes 95%CI on total
0.00
0.05
0.10
0.15
0.20
0.25
0.30
Beginning (4,326) Retrieval-shortwire (596) Doors secured (2,866) Net (539) Suitcase (615) Codend (442)
Bir
ds
/ t
ow
s
Other
Gull/kittiwake
Shearwater/petrel
N.fulmar
LAAL
Catcher Processor
Error bar indictes 95%CI on total
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
2004 (745) 2005 (2,777) 2006 (2,517) 2009 (859) 2004 (745) 2005 (2,777) 2006 (2,517) 2009 (859)
Bir
ds / t
ow
Other
Gull/kittiwake
Shearwater/petrel
N. fulmar
LAAL
All sampling Standard sampling
Species
Group
Standard
Sample
(codend)
Total
Supple-
mental
Sample
Supplemental Sample – Haulback
Capture Location
Total
Birds
(all
sources)
Ratio:
Standard
to
Supple-
mental Warp Third
Wire
Net
Wing
Unknown
Laysan Alb. 0 6 1 2 0 3 6 na
N. Fulmar 150 451 6 239 151 55 601 1:3.0
Shearwtr/
Petrel7 77 0 12 61 4 84 1:11.0
Gull 25 20 3 14 2 1 45 1:0.8
Othr/Unid. 6 97 0 76 15 6 103 1:16.2
Total 188 651 10 343 229 69 839 1:3.5
Implemented in 2010: recording supplemental mortality is
part of standard observer duties.
• Goals
– Improve monitoring, estimation, and reporting
– Identify conservation concerns for potential mitigation projects
Preliminary analysis of 2010-2015 data
Cable or gear interaction events occurred on 54 vessels; 9 vessels with >= 30 events
Of 672 events: 638 = mortality or serious injury481 due to gear143 due to cables
Total of 981 birds (mortality or serious injury);
652 due to gear315 due to cables
Species/group #
N. Fulmar 723
Shearwaters 88
Alcids 55
Laysan Alb. 45
Black-footed Alb. 10
https://www.nwfsc.noaa.gov/publications/index.cfm
Seabird Cable Strike Mitigation Workshop
• Physical Mitigation Measures1. Snatch Block 2. Water Deterrents 3. Improve Visibility of the
Third Wire 4. Streamer Lines -Warp
Booms Combination 5. Third Wire Float Device
• Behavioral Mitigation Measures• Current practice • Impractical
Photo credit: L. Shiosaka A-SHOP 2016
Pathway for seabird/trawl interaction work in Alaskan Groundfish fisheriesCharacterization
By Fishery, Gear, etc.
Improve MonitoringBetter techniques
Additional Sampling?EM?
Improve ReportingHow to Extrapolate to fleet-wide estimates
Identify Conservation Concerns
Test and Implement appropriate mitigation
measure If yes, Or… Do anyway?
Acknowledgements
• North Pacific Groundfish Observers
• Alaska Fisheries Science Center (AFSC) Observer Program Staff
• Skippers and crew of vessels
• Photos: AFSC Observer Program; Ed Melvin; At-sea Processors Assoc.
Offal
Error bar indictes 95%CI on total
0.00
0.05
0.10
0.15
0.20
No (1,462) Unk (253) Yes (5,183) No (1,462) Unk (253) Yes (5,183)
Bir
ds / t
ow
Other
Gull/kittiwake
Shearwater/petrel
N. fulmar
LAAL
All sampling Standard sampling
Shortwire
Error bar indictes 95%CI on total
0.00
0.05
0.10
0.15
0.20
0.25
0.30
No (3,420) Ukn (398) Yes (567) No (3,420) Ukn (398) Yes (567)
Bir
ds / t
ow
Other
Gull/kittiwake
Shearwater/petrel
N. fulmar
LAAL
All sampling Standard sampling
Seabird Catch Differences - Region
Error bar indictes 95%CI on total
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
AI (825) BS (7,773) GOA (797) AI (825) BS (7,773) GOA (797)
Bir
ds
/ t
ow
Other
Gull/kittiwake
Shearwater/petrel
N. fulmar
LAAL
All sampling Standard sampling
Predominate fish species in catch
Error bar indictes 95%CI on total
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
Atka
mackerel
(590)
Cod (477) Flatfish
(1,853)
Pollock
(6,010)
Rockfish
(426)
Atka
mackerel
(590)
Cod (477) Flatfish
(1,853)
Pollock
(6,010)
Rockfish
(426)
Bir
ds / t
ow
Other
Gull/kittiwake
Shearwater/petrel
N. fulmar
LAAL
All sampling Standard sampling
Seabird Catch Differences - Region
Error bar indictes 95%CI on total
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
AI (825) BS (7,773) GOA (797) AI (825) BS (7,773) GOA (797)
Bir
ds
/ t
ow
Other
Gull/kittiwake
Shearwater/petrel
N. fulmar
LAAL
All sampling Standard sampling
Predominate fish species in catch
Error bar indictes 95%CI on total
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
Atka
mackerel
(590)
Cod (477) Flatfish
(1,853)
Pollock
(6,010)
Rockfish
(426)
Atka
mackerel
(590)
Cod (477) Flatfish
(1,853)
Pollock
(6,010)
Rockfish
(426)
Bir
ds
/ t
ow
Other
Gull/kittiwake
Shearwater/petrel
N. fulmar
LAAL
All sampling Standard sampling
Shortwire
Error bar indictes 95%CI on total
0.00
0.05
0.10
0.15
0.20
0.25
0.30
No (3,420) Ukn (398) Yes (567) No (3,420) Ukn (398) Yes (567)
Bir
ds
/ t
ow
Other
Gull/kittiwake
Shearwater/petrel
N. fulmar
LAAL
All sampling Standard sampling
12/13/01 18
Offal
Error bar indictes 95%CI on total
0.00
0.05
0.10
0.15
0.20
No (1,462) Unk (253) Yes (5,183) No (1,462) Unk (253) Yes (5,183)
Bir
ds / t
ow
Other
Gull/kittiwake
Shearwater/petrel
N. fulmar
LAAL
All sampling Standard sampling
Catcher Vessels
Error bar indictes 95%CI on total
0.000
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
2004 (403) 2005 (1,085) 2006 (824) 2009 (185) 2004 (403) 2005 (1,085) 2006 (824) 2009 (185)
Bir
ds
/ t
ow
Other
Gull/kittiwake
Shearwater/petrel
N. fulmar
LAAL
Standard sampling All sampling
Recommended