1. Stock Assessment section – use of tuna data
Sam Mckechnie

2. Uses of tuna data by the stock assessment section
~ 10 scientists
Don’t collect data ourselves
Use the data managed by the data section a lot
Main work areas
Stock assessments
Analyses of management options
National-level analyses

3. Uses of tuna data by the stock assessment section
Catch and effort
Logsheet data for CPUE analyses
Data from biological sampling – otoliths, ovaries etc.
Main work areas
Stock assessments
Analyses of management options
National-level analyses
Size of fish caught
Tagging data and tag returns
Vessel no.s and size
Catch/Effort
Spatial fishing patterns
Environmental data
Bioeconomics
Observer data
Artisanal data
VMS

4. Uses of tuna data by the stock assessment section
Catch and effort
Logsheet data for CPUE analyses
Data from biological sampling – otoliths, ovaries etc.
Main work areas
Stock assessments
Analyses of management options
National-level analyses
Size of fish caught
Tagging data and tag returns
Vessel no.s and size
Catch/Effort
Spatial fishing patterns
Environmental data
Bioeconomics
Observer data
Artisanal data
VMS

5. Regular analyses One-off analyses FAD closure reports Longline reports
Country webpage updates
NPOA and shark / seabird / sea turtle management plans
One-off analyses
Requested by member countries
E.g. best options for meeting a new regulation
E.g. analyse certain data to inform about the countries fishery
Idea today was to present an example or two…

6. An example for Tokelau artisanal data
TAILS established in 2016 when SPC visited TK
Around a year or more later SPC was requested to look at the data
A 1st look to see how it was going / suggest changes
Restricted analyses to September 16 – August 17 – a calendar year

8. Data availability

9. By fishing method

10. Catch in weight
Species
compositions
Catch in no.s

15. Height of bar = catch rate (CPUE)
Width of bar = hours fished by method
So area of bar = catch by method
Examples:
Scoop netting is very productive on Atafu but fewer hours spent doing it = not huge total catches
Trolling is moderately productive on Atafu and many hours spent doing it = very large total catches

17. How to take TAILS data and estimate total catch etc.?
Finish report…
Tailor analyses to managers requests
Interesting results will come with further data collection

18. National Reports TK analyses are just one example
Other examples are very diverse
Quantification of nearshore fishing
Factors affecting longline CPUE
Seasonality and value of bycatch

19. Summary Nearly all our work requires data collected by others
The quality and impact of the analyses is directly related to the quality of the data
The stock assessment section is using a huge variety of data and often this is not reported back to the collectors
We are extremely appreciative of the collection efforts and if you’re collecting data and wonder if it’s ever used – it most probably is at one time or another
As always – let us know if you would like us to work on a topic that is of importance to you – our job is to respond to requests from member countries

20. Questions?