1. Objectives: Describe changes in growth and maturity in various stock components over long time spans Analyse reaction norms for age and size at maturation in various stock components Compare to other Atlantic cod stocks Advice to Management Icelandic cod PhD student Gudrun Marteinsdottir – University Björn Steinarsson – MRI head of TAC group Gudmundur Thordarsson – MRI Vilhjalmur Thorsteinsson – tagging MRI Chris Pampolie/Anna Danielsdottir – genetics MRI Klara Jakobsdottir – genetics (PhD student) External: Ulf Dieckman – Advice, PhD committe Skúli Skúlasson – Cod/Arctic charr collaboration

2. Icelandic cod - tasks 12 months: Database on biological data and on fishing effort on cod completed First analysis of changes in age and size at 50% maturity of cod completed 24 months: First analysis of probabilistic reaciton norms for age and size at maturation completed 36 months: Analysis of fishery-induced-changes in cod completed Probabilistic reaction norms for cod completed Analysis on the effects of climate and other environmental factors on maturation Comparative analysis on maturation in various stocks of Atl. Cod 48 months: All analysis and write-up completed and manuscripts submitted

3. Iceland - related projects Historical changes in allelic frequency at 9 microsatellite loci among cod during 1948-2003 at two main spawning sites. Klara Jakobsdottir, PhD project within METACOD Otolith growth of cod in relation to behaviour (deep vs shallow migration). Elvur Hardardottir MS project Maturity of haddock: otolith growth and its influnce on maturation. Sólveig Einarsdóttir, MS project Fishery induced changes among cod in Icelandic waters. Björn Steinarsson, Gudmundur Thordarsson and others. A new project at the MRI Maturity and growth of wolffish. Asgeir Eiriksson MS project completed – to be continued Spawning and fecundity of scallops –. Jónas Jónasson. A part of a PhD project

4. Icelandic cod - tasks 12 months: Database on biological data and on fishing effort on cod Database 1985-2004 ready (survey and samples from landed catch) – done Database 1924-1980 ? (english data ?) Fishing effort 1992-2004 – logbooks Fishing effort 1930-1992 ? ---- CPUE data available – raw data ? 12 months: First analysis of changes in age and size at 50% maturity of cod done for survey data (1980-2004) for North and South Paper 1: Changes in mean age at maturity based on historical series (1930 +) for as many components as possible (data limited) Estimate historical F (do for spawning stock and feeding stocks if possible) Attempt to estimate changes in maturity among smaller components that suffer from different fishing mortality Age/size range of spawners / spawning areas (historical changes) Environmental effects – look for abrupt changes (1984 onward) – reconstruct mat oogives.

5. Icelandic cod

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7. Proportion of shallow, intermediate and deep types in early winter migrations Vilhjalmur Thorsteinsson, in prep

8. Variability in exploitation rates between spawning grounds Spawning ground 1, ID 3.1. Near shore, shallow water 50 m 1996 release N=1042, Total recaptures 302 or 29 % Z + X = 1.2 Spawning ground 2, ID 3.4. Off shore, 100 m depth 1996 release N=574 Total recaptures 89 or 15 % Z + X = 0,6 Time in years Nlog recaptures / year Vilhjalmur Thorsteinsson, in prep

9. Icelandic cod - tasks 24 months: First analysis of probabilistic reaction norms for age and size at maturation completed Paper 2: Data: Survey data 1985-2004 Archived data back to 1930 ? Method: Start with cohorts 1985-2004 Do males and females separately Distinguish between first time and repeat spawners ? Do for earlier years (DNA otolith results indicate changes during 1950-1965) Difficult (data problems) !!!! – do other species

10. Icelandic cod - tasks 36 months: Analysis of fishery-induced-changes in cod completed Probabilistic reaction norms for cod complete Analysis on the effects of climate and other environmental factors on maturation – done for growth (?) Comparative analysis on maturation in various stocks of Atl. Cod Environment: A part of a larger MRI project Recent (1973+) changes in effort and physical and biological parameters Temp, salinity, capelin, shrimp Student: create long term indices based on historical weather readings and global environmental indices (jointly with other projects on cod recruitment) – use in reaction norm analysis Do other species ? Paper 3: Modelling - explore the role of stock structure and behavioural variation in maintaining sufficient (?) genotypic and phenotypic variation within the stock even though parts of the stocks have been exposed to high fishing pressures.