1. 27 November - 1 December 2017, UCT
INTERNATIONAL REVIEW PANEL REPORT FOR THE 2017 INTERNATIONAL FISHERIES STOCK ASSESSMENT WORKSHOP
27 November - 1 December 2017, UCT
NON TECHNICAL SUMMARY

2. The Panel Sean Cox, SFU, Canada Daniel Howell, IMR, Norway
André Punt, UW, USA
Expertise in quantitative fishery science, management procedure evaluation, stock assessment, ecosystem modelling, and statistical analysis of data

3. THEIRS NO ’I’ IN PANEL ANDRE WHY DO I HAVE TO PRESENT THIS?
The IWS Panel
THEIRS NO ’I’ IN PANEL ANDRE
WHY DO I HAVE TO PRESENT THIS?
Topics
Data-limited assessments
South African hakes
Sardines
South Coast Rock Lobster
West Coast Rock Lobster

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”
OMP may refer to: OMP Racing, an Italian manufacturer of racing car equipment. Ontario Model Parliament, a model parliament for high school students in Canada. OpenMP, an application programming interface
Wikipeda – this morning
Butterworth and Bergh, SA JMS 1987

7. Focus of the review
1. Hake (South Africa’s most valuable fishery species by far – worth more than all other fisheries together)
Hake operating (and assessment) models
Catchability, selectivity, natural mortality
Survey gear, spatial/depth coverage, and geostatistical approaches
Hake OMP revision
Reference Set operating models
OMP revisions
Methods for weighting operating models

8. Focus of the review
2. Sardine (most valuable component of South Africa’s small pelagic fishery)
Sardine OMP revision
Reference Set operating models
Risk – biomass thresholds and acceptable probability
Defining risk for highly variable sardine stocks
Spatial management
Methods to determine whether spatial management is/is not necessary

9. Focus of the review 3. West Coast Rock Lobster
Estimation of poaching removals
MCS data estimates of spatial trends
TRAFFIC estimates of illegal exports
4. South Coast Rock Lobster
OMP review
Data-poor stocks
Review of JABBA-Select

10. Overall Comments
As in previous reviews, the Panel was impressed with the quality of information presented.
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.
The Panel encourages continuing collaboration between university, industry, eNGO, compliance officials, and government researchers as a means to ensure best available data and analyses are used in decision making.
The Panel appreciated “fishery descriptions” prior to the workshop.
The Panel was pleased to see more involvement by DAFF scientists in implementing models – this is a highly skilled activity with few people adequately trained worldwide. Nevertheless, continued training and review is still essential if SA is a to retain its position as a leader in the field worldwide.

11. Data-poor assessment method
The method:
Uses limited data
Can be applied rapidly to many stocks that satisfy its requirements.
Is “in principle” endorsed for use.
However:
Like most methods, appropriate training and diagnostics checks are needed.
The method is not appropriate for all stocks and situations – the Panel provides guidance on this.

12. Hake operating models
The Panel reviewed the technical basis for the operating models to be used in the OMP revision. This is well on track, but some minor adjustments are recommended.
The Panel reviewed the scenarios for inclusion in the Reference Set of scenarios (used as the primary basis for selecting a new OMP)
Research conducted by Dr. Andrea Ross-Gillespie using a model that includes hake-on-hake predation has reduced uncertainty about natural mortality.
A new factor should be included in the Reference Set given the uncertainty of the historical split between catches of M. capensis and M. paradoxus.

13. Improving Abundance Estimates
New methods are under development to better estimate abundance from survey data using newly developed “geostatistical methods”
Evidence from South Africa and elsewhere suggest that these methods are particularly appropriate for poorly sampled / low density species.
More work is needed to fully understand these methods, but their results will be used some of the Robustness Tests for the OMP revision process.

14. Other (hake) matters
Some scientists and industry members are concerned that the M. capensis / M. paradoxus biomass ratio in model results is unrealistically high. The Panel recommends:
Using survey data to estimate the relative densities of the two species
Using the results from the predation model to understand consumption and how this changes biomass estimates.
OMP variants to consider
Explore options to assess whether methods that try to respond more quickly to new data lead to better performance (e.g. higher catch for the same risk).

15. Sardine - stock structure

16. Sardine – key challenges
The Operational Management Procedure (OMP) for the South African sardine is scheduled for revision during 2018
The Panel reviewed aspects of how candidate OMPs will be evaluated, with a focus:
How to measure “risk” given the understanding of stock structure has changed since OMP-14 was implemented.
The need (or not) for spatial management.
How to select a survey estimate of abundance below which the directed sardine fishery should be closed?

17. What is risk for sardine?
How often the spawning biomass falls below a threshold level, but what level?
the lowest level of spawning biomass provided that recruitment near this biomass was ‘reasonable’

18. How to select a risk threshold?
Expected catch
“Almost guaranteed”
catch
This calculation is done for a “tuning scenario”, which informs how risk is evaluated for other scenarios.

19. Survey estimate of abundance below which the directed sardine fishery should be closed
The risk criterion recommended above provides an objective basis for selecting this biomass:
Find the lowest level of spawning biomass provided that recruitment near this biomass was ‘reasonable.
Convert it into a survey estimate of biomass.
Account for the fact that the survey does not give the exact answer.
There are concerns that recent survey results are near the lowest on record – the Panel was asked to identify a criterion at which the directed sardine fishery might be considered for closure.

20. West coast rock lobster
Historical trends in poaching *by area* have been estimated by:
Using MCS compliance data to estimate trends in poaching
Using TRAFFIC data to estimate to absolute level of poaching in one year (2008)

21. Poaching is bad.
Uncontrolled illegal removals from any population can have severe consequences for the long-term sustainability and the Panel was very concerned to see the estimates of poaching and the estimated increase over time. Necessarily, the higher the illegal catch, the lower the legal TAC to ensure sustainability.

22. Panel Conclusions-I The basic approach is appropriate
The analysis of the DAFF MCS compliance data involves two data types:
Confiscations
Effort
The method used at present assumes all enforcement activities are equally effective at detecting illegal catches, but this appears not to be the case so analyses need to refined.
The Panel recognizes the value of DAFF Compliance to help with understanding the data and encourages their further help.

23. Panel Conclusions-II The TRAFFIC estimates of illegal catch
South African exports less South African landings
World imports less South African landings
The TRAFFIC data provide useful information on levels of poaching but
(a) some legal landings are consumed in South Africa,
(b) the method does not account for illegal catches sold in South Africa, and
(c) these data do not include illegal exports that are not declared as being South African
The estimates based on the TRAFFIC data are hence likely UNDERESTIMATES.

24. South Coast Rock Lobster
Catch-rates are about as expected from OMP-2014
There is no urgent need to update the OMP for south coast rock lobster.

25. Perhaps the next Panel needs to consider the impact of depletion of seabirds on fish productivity??