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DEEPFISHMAN Stakeholder workshop Brussels, 29-30 June 2009 DEEPFISHMAN Stakeholder worskshop Brussels 29-30 June 2009 Data availability.

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Presentation on theme: "DEEPFISHMAN Stakeholder workshop Brussels, 29-30 June 2009 DEEPFISHMAN Stakeholder worskshop Brussels 29-30 June 2009 Data availability."— Presentation transcript:

1 DEEPFISHMAN Stakeholder workshop Brussels, June 2009 DEEPFISHMAN Stakeholder worskshop Brussels June 2009 Data availability

2 DEEPFISHMAN Stakeholder workshop Brussels, June 2009 Type of DataProblems Fishing Times series of fleet, catch and effort Start time of time-series, resolution, completeness Biology (biological parameters, stock structure) Uncertainty Biodiversity By-catch, benthos, VMEs, fishing impact, Often limited, observation data provide by- catch, not all fleet covered EconomySee G. Haraldsson’s presentation SocialSee G. Haraldsson’s presentation Assessment methodologiesMost assessment exploratory, not validated even for redfish “data rich” stock ManagementData on management procedure,regulation available Impact on fleet poorly known

3 DEEPFISHMAN Stakeholder workshop Brussels, June 2009 More data allow more realistic assessment and management Example 1: Tally book data provide haul by haul catch and effort The view of the fishery is different for that for EU logbook data (hauls aggregated per day and statistical rectangle) Tally books allow : - better estimates of CPUEs - account of fishing strategies on trends in landings and CPUEs

4 DEEPFISHMAN Stakeholder workshop Brussels, June 2009 Example 2. -the effect on fishing on both exploited species and other species in the ecosystem is primarily a matter of mortality - for benthos mortality can be assessed from the frequency of trawling

5 DEEPFISHMAN Stakeholder workshop Brussels, June 2009 Example 2. -the effect on fishing on both exploited speices and other species in the ecosystem is primarily a matter of mortality - for benthos mortality can be assessed from the fequency of trawling When data resolution increases a large proportion of the seabed appears no to be fished: % of unfished bottom (% unimpacted benthos) estimated lower from VMS No change in estimated fishing mortality for target species From Piet and Quirijns (2009). The importance of scale for fishing impact estimations. can. J. Fish. Aquat. Sci.

6 DEEPFISHMAN Stakeholder workshop Brussels, June 2009 Questions Which data can be made available for stock and ecosystem assessment - VMS data: which are available? what can de done with? - Tally book data: main use might be stock assessment? - Data availability in the future (e.g. electronic logbook)


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