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