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North Pacific implementation simulation trials

If he can understand it – anyone can!. North Pacific implementation simulation trials. An Idiot’s Guide…… A Guide from an Idiot. The rmp. Initially single stock trials Data requirements very simple: Abundance estimates Catch data Testing for uncertainty…. Cla Trials!.

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North Pacific implementation simulation trials

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  1. If he can understand it – anyone can! North Pacific implementation simulation trials • An Idiot’s Guide…… • A Guide from an Idiot

  2. The rmp • Initially single stock trials • Data requirements very simple: • Abundance estimates • Catch data • Testing for uncertainty….

  3. Cla Trials! • Several different population models and associated assumptions • Different starting population levels, ranging from 5% to 99% of the ‘initial’ population size • Different MSY levels, ranging from 40% to 80% • Different MSY rates, ranging from 1% to 7% (including changes over time) • Various levels of uncertainty and biases in population size • Changes in carrying capacity (including reduction by half) • Errors in historic catch records (including underestimation by half) • Catastrophes (irregular episodic events when the population is halved) • Various frequencies of surveys

  4. Performance statistics: how to choose • Conservation objectives e.g. • Lowest population size • Initial and final population size • Population trajectories • Use objectives e.g. • Total catch over period • Catch in last ten years • Continuing catch

  5. From single stock to multi-stock • Implementation simulation trials • Specific to species/area • ‘Plausible hypotheses’ • Stock structure, productivity etc. • Sub areas Management Areas • Whaling operations • CLA options (variants): • Catch cascading/ catch capping

  6. Small Areas: Contain whales from only one biological stock or If more than one, harvesting is same ratio to relative abundance Medium Areas: Correspond to range of known or suspected biological stocks u g ss n i n e

  7. Catch cascading Apply CLA to Combination area Distribute catches to each Small Area according to the relative abundance in each Small Area

  8. What can we do with it? Data in Choose several hypotheses Choose ‘best’ hypothesis Examine performance statistics How?! Choose management option

  9. Sea of Okhotsk Kamchatka Hokkaido Sea of Japan Honshu Korea western north pacific 18 sub-areas

  10. Year 1, Year 4 Year 2, Year 5 Year 3, Year 6 Sightings surveys

  11. J-stock

  12. Baselines a and b • Baseline A (hypothesis testing) • 3-stocks (J, O, W) • W-stock sporadically in sub-area 9 • O-stock may be in sub-area 10 • Based on hypothesis testing • Hypothetic breeding ground locations • Possible feeding migrations for ‘O’ • Temporal mixing of O and J

  13. Possible feeding migration routes Some O may be in 10 Sporadic in 9

  14. Baseline c • Based on ‘boundary rank’ method • 4 stocks, 3 to west of Japan • ‘preferred hypothesis’ – no mixing with boundary at 147E and 158E • Variants: • Ow/Oe boundary at 153E with mixing • Further intrusion of Oe into 9E • Some mixing of Ow and Oe in 7 and 8

  15. Baseline d • Synthesis • 3 stock hypothesis (J, O, W) • O- and W- stocks mix across 147-162E • O stocks dominate in west • W stocks dominate in east

  16. Catch mixing matrix • Specifies the fraction of each stock in each sub-area each month by age and sex • Juveniles; Males 10+; Females 10+ • Conditioning • Select values for the operating models so that they adequately • (1) mimic the data and • (2) the dynamics of the scenario • In the context of evaluating performance

  17. April Whaling operations

  18. May-June + Aug-Sept Whaling operations

  19. July Whaling operation

  20. w w w w w w w w w Option 1: Small areas = sub-areas WHALING (W) Option 1

  21. w w w w Option 2 Small areas: 7+8, 9, 11 and 12 WHALING (W) 7W, 9W, 11, 12sw

  22. w w Option 3 Small areas: 7+8+11+12 and 9 WHALING (W) 9W, 11,

  23. w w w w Option 4 Small areas: 7W, 7E+8+12, 11 and 9 WHALING (W) 7W, 9W, 11, 12SW

  24. w w w w w w w w w Option 5 COMBINATION areas: 7+8+11+12 and 9 WHALING (W) CASCADED

  25. w w Option 6 Small areas: 7+8+11+12 and 9 WHALING (W) 7W, 11, USING CASCADING ACROSS THOSE SUB-AREAS

  26. trials • 4 baseline, 1% and 4% MSYR, J-stock at 30%K Sensitivity • J-stock depletion, 15-70% • MSYR 1-4% • Various levels of mixing and intrusion • Various assumptions of bycatch (Japan and Korea)

  27. Plausibility • Is it plausible to agree on plausibility? • Over to you, John!

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