Bycatch mitigation gear options Dr Ben Sullivan BirdLife International Global Seabird Programme
ACAP Best Practice Mitigation for Pelagic Longline Fisheries:
The most effective current approach to reduce seabird bycatch in pelagic longline fisheries is to use a combination of: • bird-scaring lines • weighted branchlines, and • night setting
The Challenge
Bait Access
Bait Access
RFMO line weighting requirements Tuna RFMOs require one of the following as a minimum standard for branchline weighting configurations: • • • •
Greater than 45g attached within 1m of the hook or; Greater than 60g attached within 3.5m of the hook or; Greater than 98g weight attached within 4m of the hook; and Positioning weights farther than 4m from the hook is not recommended.
Sliding leads versus weighted swivels
Sliding leads…are they safer for the crew? (cut-away trials on land)
On average, over range of tension treatments and distance of the weight from the hook = sliding leads had an 80% reduction in kinetic energy on impact (Sullivan et al. 2012. Safe Leads for Safe Heads. Fisheries Research 134–36:125–132)
Sliding lumo leads and distance to the hook Time (sec) Depth (m)
0
Distance astern (m)
2 60 g at 3.5 m
40 g at hook
60 g at hook
4 2
27.8
18.6
16.3
Depth 6 (m)
5
55.8
39.9
33.5
8
8
85.9
64.0
53.7
10 12
5
10
15
20
60g at 3.5 m 60g at 1 m 40g at hook 60g at hook
Line weighting: effect on catch rate?
There is no significant difference in target catch rate of 60g swivel at 2 m or 5.5 m from the hook. 92 sets: n = 41,119 hooks with 2 m and 45,979 hooks with 5.5 m leaders
Total CPUE (fish/1000 hooks) of the main target species caught for branch lines wth 2 m and 5.5 m leaders.
5 tuna commissions
• All 5 tuna commissions now have seabird bycatch mitigation requirements • Duty to act by UN Fish Stocks Agreement and FAO Code of Conduct for Responsible Fisheries • All tuna commissions require bycatch data collection
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RFMOs 2004 CCAMLR CCSBT WCPFC IOTC ICCAT IATTC Antarctic Southern W.Pacific Indian Atlantic E.Pacific RECOGNITION FIRST MITIGATION MEASURES
COLLECT BYCATCH DATA
REFINE MEASURES MONITORING & COMPLIANCE EVALUATION
RFMOs 2014 CCAMLR Antarctic RECOGNITION FIRST MITIGATION MEASURES
COLLECT BYCATCH DATA
REFINE MEASURES MONITORING & COMPLIANCE EVALUATION
CCSBT
WCPFC
IOTC
ICCAT
Southern W.Pacific Indian Atlantic
IATTC E.Pacific
BirdLife collaboration with high seas fleets •Korea meeting Busan 2012 •Taiwan meeting Kaohsiung 2013 •Spain meeting Vigo 2014 •Japan meeting mid 2015 •China meeting mid 2015? 12
Korean ‘high sea’ line weighting trials June - July 2013 – BirdLife Albatross Task Force Indian Ocean •12,000 hooks split between 65g and 40g sliding lumo leads and a control treatment •a single ‘hybrid’ bird-scaring line (mix of long and short streamers 50-80m aerial extent)
Mean fish captured
12 10 8 6
Weighted Control
4 2 0 65 g
40 g Experimental treatments
Emerging mitigation measures: hook pod
Hook pod stored in setting bins
Hook pod being set with squid bait
Trials in Australia, Brazil, New Zealand and South Africa demonstrate no reduction in target cach rate
Emerging mitigation measures: Smart Hook
Bait capsule – Graham Robertson (Australian Antarctic Division)
Thank you