General concepts and requirements Scott Large ICES stock assessment General concepts and requirements Scott Large scott.large@ices.dk @NucellaGrande #TCOM 27 January 2016

ICES stock assessments - overview ICES provides advice on the sustainable use of living marine resources and protection of the marine environment. In 2015, ICES provided advice on fishing opportunities for 225 fish stocks across the northeast Atlantic

ICES stock assessments - data 225 ”ICES” stocks ~ 90 stocks: quantitative assessments Catch data - InterCatch Survey data - DATRAS ~ 90 stocks: survey trend-based assessments ~ 40 stocks: data-poor assessments Nominal catch - Catch Statistics Explanation of data categories: ICES 2012

ICES Stock assessments - methods ICES scientists use a suite of common stock assesment methods (with varying complexity and computational needs) Virtual Population Analysis Extended Survivors Analysis (XSA; Shepherd, 1999) Time Series Analysis (TSA; Gudmundsson, 1994) State Space Stock Assessment Model (SAM; Nielsen and Berg, 2014) Stock synthesis SS3; Methot and Wetzel, 2013 Ecosystem, Mixed-fsheries, and multi-species models Globally applicable Area Disaggregated General Ecosystem Toolbox (Gadget) Size-structured, multi-species (Thorpe et al. 2015) Mixed-Fisheries (Fcube; Ulrich et al 2011) Survey-based model SURBAR; Cook, 1997 www.bluebridge-vres.eu/services/stock-assessment

Linking ICES and BlueBridge ICES uses “simple” models ICES has robust databases that handle catch and survey data Increasing need for high powered computing: Ecosystem models Mixed-fisheries models Single-stock forecasts Management strategy evaluations

Test Case – Ensemble Model Purpose – Length-based, multi-species and multi-fleet model for the Irish Sea Complexity - High Improvements – Current version is for North Sea. It is being rewritten for the Irish Sea. Takes a few hours to run – increasing computing power will enable broader resampling of models. Stage in development – Agreement with author. Will initiate code review/ discussion by 15 February. Contact/ Author: Robert Thorpe (CEFAS)

Test Case – Mixed-Fisheries assessment model Purpose – Multi-fleet model, used for ICES advice Complexity - Medium Improvements – ”Optimizer” uses a genetic algorithm and takes several hours to run. BlueBridge will allow deeper model exporation. Stage in development – Agreement with author. Will initiate code review/ discussion by 15 February. Contact/ Author: Youen Vermard (IFREMER)

Test Case – Management Strategy Evaluation Purpose – MSE for western horse mackerel Complexity - Medium Improvements – Simple test-case that will be a good point for further development. Stage in development – Agreement with author. Will initiate code review/ discussion by 15 February. Contact/ Author: José De Oliveira (CEFAS)

Test Case - eqSim Purpose - Simulates equilibrium results for a population from stock assessment output Complexity - low Improvements - Currently eqSim is not computationally limited, but it could be drastically enhanced to become more useful with BlueBridge development. Stage in development – Came up with the idea on the airplane. Will cut ticket ASAP. Contact/ Author: Colin Millar (Marine Scotland Science)

Overview ICES scientists are becoming very curious about how BlueBridge can help them. Single-species stock assessments – simple but can be improved eqSim, MSE, etc. Good place to start with 4 test cases of varying complexity. eqSim, Mixed-fisheries, and the MSE could also link directly into ICES training courses #BlueSkillz #bonus

Scott.large@ices.dk @nucellagrande