Projections under the selected Management Procedure for Greenland Halibut
Figures 1 to 5 plot the projected 95, 90 and 80% probability envelopes as well as the projected medians under the revised Management Procedure adopted in 2017 for Greenland Halibut for a series of quantities (annual catch, recruitment, and the five survey indices of abundance together with the compo...
Main Authors: | , |
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Format: | Report |
Language: | English |
Published: |
Faculty of Science
2018
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Subjects: | |
Online Access: | http://hdl.handle.net/11427/30768 https://open.uct.ac.za/bitstream/11427/30768/1/scwp18-07%20Projections%20under%20the%20selected%20Management%20Procedure%20for%20Greenland%20Halibut.pdf |
Summary: | Figures 1 to 5 plot the projected 95, 90 and 80% probability envelopes as well as the projected medians under the revised Management Procedure adopted in 2017 for Greenland Halibut for a series of quantities (annual catch, recruitment, and the five survey indices of abundance together with the composite index which combines the five) for the following SCAA-based Operating Models: - OM1 (the Baseline, using data including 2016 and the O3 set of surveys), - OM2 (larger recruitment variability with R=0.6), - OM4 (loRec – the recruitment of the first 8 years of the projections are at 50% of the level predicted by the stock-recruit function), - OM7 (110TAC – future catches are taken as 110% of the TAC) and - OM8 (noplus – zero selectivity for the plus group). The probability envelopes have been computed from a 9-point averaging approach (see Appendix below) from 500 replicates. The 9-point approach was selected as it offered a reasonable trade-off between preserving trend and eliminating “jaggedness” from Monte Carlo variation. |
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