1. Day 5 Session 1 What are the implications of the assessment for your country?

2. Country level implications
The WCPO region comprises many different countries and territories, all of whom have direct or indirect fisheries based economic interests in the regions tuna resources.
The species of most economic or social importance varies between countries/territories (for any given species, some countries will have significant economic reliance, and others very little etc. Some have significant reliance on multiple species).
Hence, the national level implications of any given assessment will differ depending on the species and between countries.

3. Country level implications
Determining the implications of a given assessment for a given country will depend initially on the following:
A) Your countries contribution to overall fishing impacts
B) Your countries economic, social or food security dependance on the resource being assessed
C) The outcomes of the assessment
D) The management options being considered in response to the assessment outcomes

4. What is next?
We have identified the ‘best’ model and accepted that it is a ‘good’ representation of what is happening to the stock and stock status
What are the most important outputs for managers from the model?
What do we need to know about these outputs?
(This is the basis to providing advice to managers arising from assessments?)

5. Reference Paper We will use the 2007 Yellowfin SA as an example as;
It has been peer-reviewed at SC-3
You have all been exposed to the 2007 YFT assessment at SC3 and aware discussions
All WCPO countries capture yellowfin
Therefore, the you should be familiar with the assessment
Stock Assessment Workshop II Day 2 Session 4

6. Key Management Outputs
To pull out the key management outputs we need to firstly identify what the key management questions are (regarding resource status):
What is the current condition of the stock? (STATUS)
Why is it in that condition? (CAUSE)
What can we do in response? (MANAGEMENT OPTIONS)
As the scientific advisors to your department, you need to understand the answers to these questions in some detail. However in presenting the information to your superiors, you need to present that information in a manner easily understood. The level of

7. Key Management Outputs
As the scientific advisors to your department, you need to understand the answers to these questions in some detail. However in presenting the information to your superiors, you need to present that information in a manner easily understood.
The level of technical detail provided to them will depend on your audience, but it is critical that in simplifying your advice (if required) that the accuracy of your statements to answer those three questions are not compromised!

8. Key Management Outputs
So….to answer these three questions, which key information/outputs from the assessments do we need to focus on?
Well firstly, before pulling that information out, make sure you have a good understanding or picture of the fishery.
That can be quickly attained by pulling out 3 key pieces of information pertaining to:
1. Where are the fish?
2. Where are the catches taken and by what gears?
3. How many fisheries are there?

9. Fishery Overview – Pt1 Where are the fish (biomass by region)?

10. Fishery Overview Pt2 Where are the catches and by what gears?
How many fisheries?
= 24! (PS ASS, PS UNASS, LL, PL, HL, OTH GEARS)

11. Key Management Outputs
Now we can focus on our key management questions
What is the current condition of the stock? (STATUS)
Why is it in that condition? (CAUSE)
What can we do in response? (MANAGEMENT OPTIONS)

12. (What plots would you choose?)
What is the current condition of the stock? (STATUS)
(What plots would you choose?)

13. 1. What is the current condition of the stock?
Point estimate just below overfishing but high probability of overfishing (47%)
Precautionary approach would suggest ….what?
SC3 advice - Yellowfin – reduce fishing mortality from average level

14. 1. What is the current condition of the stock?
Be aware of the uncertainties identified by sensitivity analyses and uncertainty (confidence limits) of the base case model.
Stock Assessment Workshop II Day 2 Session 4

15. 2. What is the main cause of the current stock condition/status
(Which plots best explain why the resource is in its current status?)

16. 2. Why is the stock in that condition?
This question can be subdivided:
Where are the major impacts (which regions)?
Which fisheries/gears are having the highest impacts in each region and overall?
Which components (age classes) of the stock are being impacted upon the most?
Has recruitment been impacted?

17. Where are the major impacts occuring and which gears are responsible?
Plot 1 – Catch by gear and region
Most (~75%) in region 3 [western WCPO]
Region 4 next most important region;
different history to region 3; late start to PS
recent catches declining;
strong among-year variability (why?)
Insignificant catches in other regions
[Plotted on the same scale for the y-axes]
Stock Assessment Workshop II Day 2 Session 4

18. Where are the major impacts occuring and which gears are responsible?
Plot 2 – Impacts on total biomass by region and gear.
[Different y-axes]
Highest in region 3
> 60%
High in regions 1 and 3 (>30%)
[But low biomass in region 1]
Low in other regions
But low biomass in sub-equatorial regions
talk about the patterns in different regions and why these pattern exists
Both temporal and method-fishery.
Stock Assessment Workshop II Day 2 Session 4

19. Where are the major impacts occuring and which gears are responsible?
Plot 3 – Impacts on spawningl biomass by region and gear.
[Different y-axes]
Impacts of some method fisheries are not restricted to the region in which they occur (Why…fish move!)
e.g. PH/ID (green R3) Only in region 3
But effects estimated in regions 1 – 5.
Stock Assessment Workshop II Day 2 Session 4

20. Where are the major impacts occuring and which gears are responsible?
Plot 4 – Movements of regional recruits to other regions
This explains why catches by a fishery in one region can impact biomass in another region….fisheries can catch fish that might otherwise have moved into an adjacent region.
Whats different about region 6? No immigration/emmigration
Current tagging programme will hopefully help improve these movement estimates

21. Where are the major impacts occuring and which gears are responsible?
Spawning
Biomass
Plot 5 - Spawning biomass versus total biomass reductions
About a 55% reduction from unfished levels
Greater reduction in SB than B. Why?
Similar patterns between SB and B impacts x gear and through time,
Total
Biomass
Link back SB and B differences to the models-only a proportion of the biomass is reproductive
Stock Assessment Workshop II Day 2 Session 4

22. Where are the major impacts occuring and which gears are responsible?
Plot 6a – Proportional Reductions in Biomass by region
Different levels in different regions
Virtually no decline in region 2
History also different
e.g. Regions 1 and 5 – large declines are only recent
Stock Assessment Workshop II Day 2 Session 4

23. Where are the major impacts occuring and which gears are responsible?
Plot 6b - Biomass changes in the absence of fishing
What do you see?
Little difference for regions
e.g. regions 1, 2, 5 and 6
But little biomass in these regions
Fished and unfished trends are similar in region 4
Moderate impacts of fishing
Biggest difference in region 3; difference increasing
Stock Assessment Workshop II Day 2 Session 4

24. Which components (age classes) of the stock are most impacted?
Plot 1 - Size of fish caught by gear
Biological factors
some fish captured before they mature
some fish captured at or above maturity
Age at start of maturity
50% mature at age 8 (2 yrs)
100% mature at age 10 (2.5 yrs)
Stock Assessment Workshop II Day 2 Session 4

25. Which components (age classes) of the stock are most impacted?
Plot 2 - Fishing mortality at age by decade
How has fishing mortality at age changed over time? Why?
Increasing F in older age classes 50s-80s
[expansion of LL fishery]
Increasing F in young age classes from 80s
[PS fishery expansion]
F highest in 2005
Stock Assessment Workshop II Day 2 Session 4

26. Which components (age classes) of the stock are most impacted?
[Note: different scales on y-axes]
Plot 3 – Fishing mortality at age by region ( )
Why the difference in fishing mortality at age between regions (e.g. Region 1 and 2)?
Highest in R3 (R1)
↑ F in v.young fish in Rs 3 and 4 (PS)
↑exploitation of age classes 5-10 in Rs 4-6
Stock Assessment Workshop II Day 2 Session 4

27. Which components (age classes) of the stock are most impacted?
Plot 4 – Adult and juvenile fishing mortality by year
What is happening to exploitation rates (overall)?
Why?
Adult; juveniles
Increased rapidly
Highest in Juveniles (PS)
Recent declines (?)

28. Has recruitment been impacted by fishing?
Plot 1 – Estimated recruitment by region
Regionally within model
Region 1~ 50 mill. (12%)
Region 2~ 5 mill. (1%)
Region 3~ 125 mill (31%)
Region 4~ 125 mill (31%)
Region 5~ 80 mill. (20%)
Region 6~ 20 mill. (5%)
No consistant or obvious declining trends in recruitment
Stock Assessment Workshop II Day 2 Session 4

29. Has recruitment been impacted by fishing?
Plot 2 – Stock recruitment relationship anad quarterly estimates of recruitment.
High steepness
High variability around mean (recruitment could be high or low for a given spawning biomass (SB)) Why?
Recent SBs are relatively low
Estimated recruitments do not appear to reach same maxima in recent quarters??
Stock Assessment Workshop II Day 2 Session 4

30. Summary of Fishery Impact Observations
Yellowfin
Overall fishery impacts on adult biomass are moderate, with adult biomass ~30% of unexploited level
Impacts are more evenly spread across fisheries – most significant are ID, PH miscellaneous small-fish fisheries, PH handline, PS FAD/log, PS unassociated and longline
Like bigeye, impacts are high only in the tropical regions
Management measures that are effective in reducing fishing mortality for bigeye will also reduce the currently significant risk that overfishing is occurring for yellowfin

31. 3. What can we do about it? (Analyses of Management Options)
**Note, switch to BET for Management Options

32. Analysis of Management Options
Yellowfin
Bigeye

33. Analysis of Management Options
fishery impact

34. Analysis of Management Options
SC Scientific Advice
Bigeye – reduce fishing mortality 25% from average level
Yellowfin – reduce fishing mortality from average level
WCPFC response to date – to restrict fishing effort or catches to 2004 levels
This response is unlikely to remove overfishing of bigeye tuna or reduce the risk of overfishing yellowfin tuna

35. BET 2006 - F in relation to BMSY
Analysis of Management Options
BET F in relation to BMSY

36. Analysis of Management Options
BET 2007 – Scenario = PH/ID effort is constant and equal to recent average, while PS UNASS effort level is irrelevant as it does not catch BET.
F/Fmsy < 1
F/Fmsy > 1
Large reductions in effort required to achieve Fmsy for BET.
LL 50%, PS 0%
LL 40%, PS 15%
LL 30%, PS 30%
LL 20%, PS 45%
LL 10%, PS >50%
LL 0%, PS >>50%

37. Management Measures Under Consideration
Analysis of Management Options
Management Measures Under Consideration
A three-month ban on FAD sets in PNA EEZs (proposed PNA measure)
Permanent closure of the high-seas pockets (proposed PNA measure)
Full catch retention (no discarding) in PNA EEZs (proposed PNA measure)
25% reduction in bigeye-targeting longline effort (FFC proposal to WCPFC)

38. Effect of Management Measures

39. Purse Seine Set Types

40. Purse Seine Set Types

41. Effect of Management Measures

42. Summary of Fishery Impact Observations
Bigeye
Overall fishery impacts on adult biomass are high, with adult biomass <20% of unexploited level
Longline fishery currently responsible for ~50% of total fishery impact on adult biomass
Other impacts are from catches of small juveniles – PS FAD/log sets and ID/PH fisheries
It is clear that management measures need to target both longline and small juvenile sectors
Impacts are high only in the tropical region and this is where management should logically be targeted

43. Potential Management Measures (What might work from a scientific point of view)
Objective is to reduce fishing mortality of bigeye and yellowfin
Equivalent to the proportion of the stock harvested, fishery impact
An important policy objective is also to minimize impacts on PS skipjack and LL albacore (South Pacific) catches

44. Potential Longline Measures
Direct control of effort or catch
Catch control (TAC)
Disadvantage is that TAC would need to respond to changes in population size resulting from recruitment, e.g. the TAC under current (high levels of recruitment) might be ~80,000 mt, but ~45,000 mt under long-term average recruitment
Monitoring implications

45. Potential Longline Measures
Effort control (TAE)
Advantage is that the same TAE can be applied across variable recruitment regimes
Need to guard against “effort creep” by periodic revision of the TAE
Appropriate to restrict spatially to the tropical area, e.g. 20N - 10S
Most longline impacts occur in this zone
Would avoid unnecessary restrictions on fisheries targeting albacore (South Pacific) and swordfish
But would need to monitor non-tropical fisheries for any increase in bigeye targeting
Various allocation options for TAEs or TACs

46. Potential Longline Measures
Other possibilities?
Closed areas: unlikely to work unless very large as effort could shift to open areas
Closed seasons: could possibly work but would need to be long enough so that vessels could not simply coincide regular travelling or down time, i.e. it would need to result in a real decrease in fishing effort (hooks or sets)
Would still need total effort restrictions in either case

47. Potential Purse Seine Measures
Catch control
i.e. have overall or vessel-specific quotas or allowable % of catch for bigeye and small yellowfin (essentially treat as a by-catch)
Would need to be set low enough to avoid over-fishing during low-recruitment periods
Would require real-time monitoring, probably by observer-based sampling
100% observer coverage
Once quota reached, stop fishing (FAD/log sets) for the year
Puts onus on industry to work out how to avoid bigeye and small yellowfin

48. Conclusions
There remains a considerable disparity between scientific advice and WCPFC response
Overfishing of bigeye and yellowfin is likely to continue, and possibly worsen, unless further measures are implemented
Current measures proposed by PNA/FFA could be effective in reducing or even removing overfishing
However, evolution of the purse seine fishery (FADs) is critical – any long-term solution will need incentives for industry to minimize catches of small bigeye (and yellowfin). Potential role for the Vessel Days Scheme.

49. Potential Purse Seine Measures
Effort control (indiscriminant wrt set type)
Essentially what we have now with CMM (national waters) and CMM (high seas)
Cannot achieve bigeye/yellowfin conservation objectives without severely impacting skipjack catches
Cannot guarantee level of impact on bigeye without any reference to set type

50. Potential Purse Seine Measures
Effort control targeting FAD/log sets
Could allow reduction of small bigeye and yellowfin mortality with less impact on skipjack catches
Initial objective might be to move from current situation of 40-60% FAD/log sets to 20-30%
Various ways it might be implemented
Closure period for FAD/log sets (as long as frequency of FAD/log sets in open period does not increase, total effort restrictions still apply)
Incentive schemes within a comprehensive VDS – free or heavily discounted days for non-FAD/log operations
All options require 100% observer coverage
Disadvantage: reduced efficiency (fuel), higher costs. Risk is that some operators would not fish at all, with resulting impact on skipjack catches

51. Potential Purse Seine Measures
Other possibilities?
Net depth restrictions
Restrictions on time of set
Almost all FAD/log sets are made in pre-dawn hours
Restrictions on mesh size
If effective in allowing escape of small bigeye and yellowfin, skipjack of similar size would also likely escape
Moon phase – lower bigeye catches on full moon?

52. Potential Purse Seine Measures
The slide is from some of our tagging work in PNG
Shows that there is not great potential to exploit different depth behaviour of the 3 species
The green rectangle shows the characteristic time window for PS FAD sets

53. Potential Purse Seine Measures
Other possibilities?
Net depth restrictions
Restrictions on time of set
Almost all FAD/log sets are made in pre-dawn hours
Restrictions on mesh size
If effective in allowing escape of small bigeye and yellowfin, skipjack of similar size would also likely escape
Moon phase – lower bigeye catches on full moon?

54. What are we left with? Longline effort restrictions in the tropics
Purse seine effort control in the tropics
On total purse seine effort
With additional measures to (a) encourage or (b) require some transfer of FAD/log effort to unassociated set effort
Role of processors in providing incentives
Ability of operators to choose sets based on school characteristics
Possibly consideration of measures to prevent any expansion of FAD-based effort east of ~170W
Vessel-specific catch quotas for small bigeye and yellowfin
Need for meaningful restrictions on small bigeye and yellowfin catches in Indonesia/Philippines

55. Have different implications for different countries
DISCUSSION
HOW AND WHY WILL:
A. Assessment results
B. Management options
Have different implications for different countries
Need to consider specifically:

56. GROUP EXERCISE
Using your bigeye or albacore assessment papers, create a series of notes/slides regarding:
What is the current condition of the stock?
Why is it in that condition?
Where are the major impacts (which regions)?
Which fisheries/gears are having the highest impacts in each region and overall?
Which components (age classes) of the stock are being impacted upon the most?
Has recruitment been impacted?
Does the assessment suggest a need for a specific management response? Why or why not? What are the potential management response options?
How do the implications of the assessment differ for different countries represented in your group

57. GROUP EXERCISE
Electronic copies of the assessment papers, plus some related management options papers and powerpoint presentations, are available on the “Temp:” drive, which can be accessed via computers in the Computer Lab.
More specifically: Temp\DonB\Workshop 2\Background Materials