Benchmarking growth of farmed Atlantic cod, Gadus morhua: a case study in Ireland: A case study in Ireland

The growth performance of different stocks of farmed North Atlantic cod over several years in Irish rearing conditions is described. The growth trajectories for all stocks reared were similar. From all growth data, it was found that weight at 180 and 365 days post hatch (dph), with mean values of 17.7 and 158.7 g, respectively, are accessible and useful indicators of hatchery growth performance. The importance of using standard benchmarking points to facilitate concerted and improved research efforts is highlighted here. Growth performance was evaluated against existing predictive models and these were found to be quite robust and very useful within certain constraints. Comparative growth modelling using prevailing ambient sea surface temperature regimes for five different countries (Ireland, Norway, Canada, Iceland and the Faeroes) was also undertaken. Harvest size of 2.5 kg was estimated to be reached in approximately 36 months post hatch in the Faeroes, 38 months in Ireland, 37 months in Norway, 40 months for Canada and up to 42 months in Iceland.