| Summary: | This report presents a framework to model density dependent growth for the North East Atlantic mackerel. The model used is the classical von Bertalanffy equation, but modified so that growth is reduced when stock size increases. The model developed was able to reproduce quite closely the trends in the observed historical weight-at-age data. This framework can therefore be incorporated in the simulation tool used for the mackerel management plan evaluation. But since the actual mechanisms through which stock size affects growth are not identified, density dependent growth should not be used as the base case scenario in simulations. However it can be used in sensitivity tests which can be conducted to assess the potential impact of density dependent growth on simulation output, such as Fmsy.
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