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Mauritius, 18-20 March 2014

Where does my data go? Preparation of files for the assessments of IOTC stocks and use of data for the assessments of IOTC species. Mauritius, 18-20 March 2014 Compliance Workshop: Collection and reporting of Fisheries data to IOTC. Sponsored by BOBLME-IOC-SmartFish-IOTC.

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Mauritius, 18-20 March 2014

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  1. Where does my data go?Preparation of files for the assessments of IOTC stocks and use of data for the assessments of IOTC species Mauritius, 18-20 March 2014 Compliance Workshop: Collection and reporting of Fisheries data to IOTC Sponsored by BOBLME-IOC-SmartFish-IOTC

  2. Building blocks of Tuna stock assessments • Catch-and-effort data • Landed (Nominal) catch (sale slips; sampling) • Discard levels (observers; logbooks) • Effort (logbooks; sampling) • Size/age composition (sampling; tagging) • Abundance trends • Fishery CPUE (fine-scale operational data from logbooks) • [Size/age/sex composition (logbooks; sampling; tagging)] • Exploitation rates (tagging) • Life history information • Longevity/natural mortality (tagging; otoliths) • Growth (tagging; otoliths) • Maturation (biological samples) Spatial and seasonal patterns Routine Data Collection Data Collection through specific projects (updated regularly)

  3. Building blocks of management advice Slide from R. Method modified by Joseph E. Powers

  4. Input files prepared for the assessments • IOTC SECRETARIAT • Catch [and effort] data by species, time-period (usually quarter), fishery (groups of Flag-Gear combinations depending on the selectivity) and areas (depending on the dynamics of the fleets and species for assessment) • Number of fish sampled by species, size bin, time-period… (as above) • Length-weight, growth, and other functions used for each species • Life history information • FLAG STATES • Indices of abundance (from as many fleets as possible); estimated using fine-scale operational data (logbooks)

  5. Example of BET input files Bigeye tuna SS3 Assessment

  6. Steps in the preparation of datasets NOMINAL CATCH

  7. CATCH-AND-EFFORT

  8. Steps in the preparation of datasets (cont.) INDIVIDUAL LENGTH DATA

  9. Nominal Catch: What is missing ? Attending the Workshop All IOTC Species • The majority of countries attending the Workshop have not reported nominal catches as per the standards agreed by the IOTC • On the contrary, other countries have adhered in general to the standards, for most IOTC species • The IOTC Secretariat has to estimate catches when reports are incomplete  75% of the catches over the history of the fishery Not attending the Workshop Attending the Workshop By Species

  10. Catch-and-Effort: What is missing ? Attending the Workshop All IOTC Species • The majority of countries attending the Workshop have not reported catch-and-effort data at all (red) • Where reported, catch and effort is not by the standards in most cases (light green) • On the contrary, levels of reporting for other countries are higher with data reported by the standards in most cases • Levels of reporting have only slightly improved over time and remain very low Not attending the Workshop Attending the Workshop By Species

  11. Size Frequency: What is missing ? Attending the Workshop All IOTC Species • The majority of countries attending the Workshop have not reported size frequency data at all (red) • Where reported, size frequency is not by the standards in most cases (light green; orange) • On the contrary, levels of reporting for other countries are higher with data reported by the standards in most cases • Levels of reporting have only slightly improved over time and remain very low Not attending the Workshop Attending the Workshop By Species

  12. Conclusion The quality of the management advice depends on the quality of the data that feeds the assessment and the uncertainty associated to the results; If data completeness and quality does not improve we have to live with what we have and take more conservative actions to ensure that IOTC stocks are safe

  13. Thank You for Your Attention Mauritius, 18-20 March 2014 Compliance Workshop: Collection and reporting of Fisheries data to IOTC Sponsored by BOBLME-IOC-SmartFish-IOTC www.iotc.org

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