1. 27 November - 1 December 2017, UCT
The Panel
Who is this:
Henning, Kim or Doug??
INTERNATIONAL REVIEW PANEL REPORT FOR THE 2018 INTERNATIONAL FISHERIES STOCK ASSESSMENT WORKSHOP
27 November - 1 December 2017, UCT
NON TECHNICAL SUMMARY

2. The Panel Sean Cox, SFU, Canada Sarah Gaichas, NMFS, USA
Malcolm Haddon, CSIRO, Australia
André Punt, UW, USA
Expertise in quantitative fishery science, management procedure evaluation, stock assessment, ecosystem modelling, and statistical analysis of data

3. Sean, I am not sure about this…
The IWS Panel
Topics
South African hakes
Sardines
West Coast Rock Lobster
Data-moderate stock assessment
Doug, I knight thee…
Sean, I am not sure about this…
Positive bias in Doug’s hair

4. With Special Guest Stars
Chef Jon Gaboric prepared this butter poached lobster with a corn and miso puree

5. Reminder OMPs and their testing
OMPs: The combination of pre- defined data, together with an algorithm to which such data are input to provide a value for a set of implementable management measures.
OMPs are tested to check that they achieve the best possible balance among the objectives.
South Africa (thanks largely to the work at MARAM) is a world leader in the use of OMPs.
Risk, catch, etc

6. Trade-offs
Underlying principle: “if a strategy does not perform adequately in computer simulations, why would you expect it perform adequately in the real world”
Butterworth and Bergh, SA JMS 1987

7. Focus of the review
Hake Reference Case operating (and assessment) models
Is the new reference set of models ready for use?
How do model changes impact resource status?
Hake OMP revision
Is the proposed OMP sufficiently robust to uncertainty about future survey frequency and the vessel availability?
Do the scenarios being considered sufficiently cover uncertainty?

8. Focus of the review
Sardine (most valuable component of South Africa’s small pelagic fishery)
How do we maintain a constant level of risk when some of our ideas of how the system “works” have changed (two vs one component)?
Data-moderate assessments
Has the JABBA-Select method developed by DAFF scientists been sufficiently developed, documented and tested to be used routinely?

9. Focus of the review West Coast Rock Lobster
Estimation of poaching removals
Have the recommendations from the 2017 review has been implemented appropriately?
Estimation of population
Is the assessment of current stock status the best that can be done given the available data?
Projection methodology
Are the assumptions underlying the current way projections are undertaken appropriate?

10. Overall Comments
As in previous reviews, the Panel was impressed with the quality of information presented. More work was done by the MARAM staff during that workshop than in previous years. Well done all!!
There are major logistical issues (funding, timing of meetings) that hamper making maximum progress on key topics.
There is a need for greater attention to be given to error checking of assessments: consideration should be given to technical checking an assessment before it is presented at a DAFF Working Group
The Panel thanked the participants for their hard work preparing and presenting the workshop papers, for the extra analyses undertaken during the workshop, and for the informative input provided during discussions.

11. Data-moderate assessment method
The method:
Uses limited data
Can be applied rapidly to many stocks that satisfy its requirements.
Conclusions:
The method has been improved since the last review based on Panel recommendations
The method is at least as good as some much more complex approaches.
The method is endorsed for use
The next step is for the methods to be applied to data for local linefish stocks.

12. Hake The Panel reviewed the technical basis for the stock assessment
The Panel reviewed the technical basis for the operating models to be used in the OMP revision.
The Panel reviewed the scenarios for inclusion in the Reference Set of scenarios (used as the primary basis for selecting a new OMP)

13. Why have estimates of female biomass relative to BMSY (the minimum target for passing MSC certification) changed?
Corrections to earlier methodology
Updated natural mortality from a model that allows for predation and cannibalism.
More optimistic data.
But the review identified issues in some of the models which need to addressed (and reviewed by the Working Group) before any revised models are used for future management purposes. There was insufficient time for the required changes to be made (and tested).

14. The IWS 2018 super hero A =

15. Other Recommendations
The models in the reference set need to be updated (the Panel has provided suggestions for “next steps”)
Proposed robustness trials are appropriate and a few alternatives were suggested to more adequately understand the consequences of reductions in future survey capability A

16. Sardine: questions, and recommendations (I)
Methods for future recruitment variation
Mimic variation in past recruitments
Simple methods for overall assessment uncertainty
The Panel identified a way for the analysts to characterize uncertainty that should speed up OMP evaluations
Apply consistent risk metrics given new model structure
Use additional performance metrics when evaluating risk to the stock

17. Sardine: risk metrics recommendations (II)
Use consistent risk methods
Compare risk of procedures with (non-zero) risk of no catch
Continue OMP-14 “leftward shift” approach, but base the calculation on spawning and not total biomass
Consider risk thresholds appropriate to the current production regime (and provide evidence for differences in regimes)
Consider all performance statistics in OMP selection
Apply additional risk metrics
Ensure that trials adequately consider possible fishery dynamics (e.g., the fishing fleet is unable to move to the south coast at the rate expected)
Use risk metrics reflecting concerns (e.g., consecutive years below threshold)

18. West Coast Rock Lobster

19. Estimation of Poaching Removals
Relatively small sample size in ‘NEW’ database
OLDdb
Effort
NEWdb
Relatively Imprecise
Efficiency Estimates
More Precise
Poaching Estimates
OLDdb +
NEWdb
Panel Suggests:
Key data needs:
Record cases in which no confiscations occurred in the NEWdb
Obtain data on local sales to better estimate total poaching
Focused on Analysis rather than Delphi approach used to develop scenarios

20. Estimation of population
New Data Available
New estimation of 2010 Recruitment.
No reasons that updated assessment should not be used for management
2018 = 1.8%
of 1910 Level!

21. Suggestions for Improvements
The Panel has suggestions that could assist and possibly improve the rock lobster assessment.
More Data – especially length-composition. We need this to estimate recruitment – a core input to projections.
The model structure and diagnostics can be updated for more efficient calculation.

22. Current Projections – The Stock Status is Dire

23. Current Projections – The Stock Status is Dire
2006
2.15%B1910
2025
2.31%B1910
2018
1.8%B1910
1 Step
2 Step
TACS
1 Step; 2 step
2019:

24. Projection methodology
Ideally projections should consider
a) recruitment uncertainty,
b) somatic growth, and
c) resource abundance.
The Panel has provided guidance on all of these aspects. The alternative computations may imply that the second step reduction in TAC (2018/19 to 2019/20 season) need not be so large as currently predicted (840t).
But interpretation of the projection results should also focus on minimizing the probability of further decline
Results (stock size and sustainable catches) will improve if poaching can be appreciably reduced

25. Lets move from Powerpoint Poisoning to questions

26. Biomass Projection with No TAC Change