Simulation Of Cod Growth Based On Food Supply And Water Temperature Data

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Numerous investigations have shown that growth rate of the Barents Sea cod is primarily determined by two factors, food supply and water temperature. With this in view, a prognostic model for estimation of cod growth has been developed. Weight increment rate in cod was computed on the basis of food consumption expressed as energy units. The model is based on the concepts of maximum food consumption depending on fish length and environment temperature, of the feeding level depending on food supply, as well as of food suitability coefficients and prey availability. Model parameters were estimated using cod stomach data for 1984-1999 presented in the Russian-Norwegian database. The data derived by quantitative analysis of cod stomach content were aggregated on a quarterly basis, without area differentiation. Heat content in the Barents Sea was defined by the data on mean annual temperature in the 150-200 m layer of the Kola Meridian section. All computations by the model were cohort-based, with a time step of one year. Tuning of the model by the observed data, as well as simulation of cod growth at different water temperatures and food supply conditions, has indicated the extent to which cod stock dynamics in the Barents Sea is affected by the above factors