Stock Assessment section – use of tuna data Sam Mckechnie

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

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

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

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…

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

Data availability

By fishing method

Catch in weight Species compositions Catch in no.s

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

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

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

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

Questions?