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Observer data analyses: bycatch composition
Valerie Allain SPC- OFP Ecosystem Monitoring and Analyses
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New Caledonia longline fishery
21 longliners in 2009
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Observer programme National observer programme started in 2001
From 1992 to 2010: - 141 trips -1080 sets hooks National observer programme started in 2001 1 coordinator and 2 observers Increasing observation
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In 2009, observation rate exceeded the 5% limit with a rate of 7
In 2009, observation rate exceeded the 5% limit with a rate of 7.8% in number of hooks and 57.1% in number of boats
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Spatial distribution of observed hooks
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Observer data analysis
More than 64,000 fish observed since 1992 102 species: 3 target species 3 marine mammal species 3 seabird species 7 billfish species 29 shark species 3 turtle species 53 other fish species
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Frequency of observation
ALB YFT DOL ALX BSH SKJ WAH BET LAG MLS GBA SSP LEC PLS SMA SWO FAL BUM ALO GES OCS SFA BLM BAR SHK UNS GEP AML BRZ TIG Target Shark Billfish Other bycatch Frequency of observation 21 species observed in more than 10% of the sets
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Percentage of the number of sets
Number of species observed
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Catch composition Percentage in weight
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Examination in detail of the 2 periods sampled to identify potential sampling biases:
Spatial coverage and monthly coverage are identical Boats observed: % of sets observed from fishing company 1 % of sets observed from fishing company 1 and 26% from fishing company 2 Observer effect: 3 main observers who observed 53, 26 and 14% of hook numbers 2 observers provide similar results, one differs with anomalies indicating misreporting Observer 1 Observer 2 Observer 3
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Percentage in weight
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Wire trace on branchline Bas-de-ligne en acier
No Yes No information recorded Percentage Years
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Observer data Logsheet
Target species Billfish Sharks Other bycatch
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Catch fate
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Discarding reasons BLM BUM SFA SWO MLS SSP BRZ LAG WAH DOL SKJ SMK BET
Shark damage Too small Whale damage Fins retained Too difficult to land Other causes BLM BUM SFA SWO MLS SSP BRZ LAG WAH DOL SKJ SMK BET YFT ALB Percentage in number of fish
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Discarded species survival
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Discarded species survival
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Sharkfin exports Dry fish exports (kg) Years
Estimated weight of fresh shark (tons) Years
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Data issues -misreporting: some species not reported e.g. lancetfish, sharks -species identification: some misidentification e.g. marlins -incomplete information: details on fishing gears, condition of discarded fish
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