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Dive into the intricacies of fisheries management with this guide that covers single stock trials, data requirements, population models, and more. Learn about different MSY levels, uncertainty testing, and conservation objectives across multiple stock scenarios. The guide also explores various management options for different areas, including whaling operations and catch cascading. Discover how to choose the best hypotheses, examine performance statistics, and make informed management decisions for sustainable fishing practices. With detailed explanations and simulation trials, this guide is essential for anyone involved in fisheries management in the North Pacific region.
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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! • 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
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
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
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
Catch cascading Apply CLA to Combination area Distribute catches to each Small Area according to the relative abundance in each Small Area
What can we do with it? Data in Choose several hypotheses Choose ‘best’ hypothesis Examine performance statistics How?! Choose management option
Sea of Okhotsk Kamchatka Hokkaido Sea of Japan Honshu Korea western north pacific 18 sub-areas
Year 1, Year 4 Year 2, Year 5 Year 3, Year 6 Sightings surveys
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
Possible feeding migration routes Some O may be in 10 Sporadic in 9
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
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
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
April Whaling operations
May-June + Aug-Sept Whaling operations
July Whaling operation
w w w w w w w w w Option 1: Small areas = sub-areas WHALING (W) Option 1
w w w w Option 2 Small areas: 7+8, 9, 11 and 12 WHALING (W) 7W, 9W, 11, 12sw
w w Option 3 Small areas: 7+8+11+12 and 9 WHALING (W) 9W, 11,
w w w w Option 4 Small areas: 7W, 7E+8+12, 11 and 9 WHALING (W) 7W, 9W, 11, 12SW
w w w w w w w w w Option 5 COMBINATION areas: 7+8+11+12 and 9 WHALING (W) CASCADED
w w Option 6 Small areas: 7+8+11+12 and 9 WHALING (W) 7W, 11, USING CASCADING ACROSS THOSE SUB-AREAS
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)
Plausibility • Is it plausible to agree on plausibility? • Over to you, John!