An evaluation of the stock structure of North Sea cod, haddock, and whiting since 1920, together with a consideration of the impacts of fisheries and predation effects on their biomass and recruitment

Abstract

Time series of population-at-age and fishing mortality rate estimates are extended back to 1921 for North Sea cod, and to 1920 for North Sea haddock and whiting. The extended time series are used to examine the ability of various factors to explain the changes in biomass and recruitment of these roundfish stocks during much of the twentieth century. In particular, the possible impacts of fishing pressure and multispecies interactions are explored.