Migration, distribution and spatial dynamics of plaice, and sole in the North Sea and adjacent areas

Overview

The major aim was to describe the migration patterns of two of the economically most important species of flatfish (plaice, sole) in the central and southern North Sea and adjacent areas in relation to their nursery grounds and spawning areas. The research programme aimed: (a) to identify and describe patterns of migration of the two species of fish in the southern and central North Sea and adjacent areas (eastern English Channel and Skagerrak) in relation to the location of their spawning and nursery grounds; (b) to identify the underlying biological mechanisms of migration; (c) to establish the link between the behaviour of the fish and key physical factors in the marine environment; and (d) to incorporate the results in a predictive model.

Three complementary approaches were applied: (1) Four hundred and eighty-four electronic data storage tags (DST) were released at 9 North Sea locations to obtain information on the behaviour of free-ranging individual plaice over the long periods associated with migration and seasonal changes in distribution. The data from 111 returned DST (and an additional 34 DST from a previous release by Cefas), were used to reconstruct the movements of these fish. The data were interpreted initially using a tidal stream simulation model, which was based on known patterns of migratory behaviour in the two species. (2) The large body of conventional tagging (CT) data on the two species held by the four fisheries institutes involved in the project was collated and analysed using methods previously developed to describe the spatial dynamics of North Sea plaice populations. (3) Migration and dispersion indices derived by these two independent methods were synthesised to produce a predictive model of fish movement that took into account the basic mechanisms of migration and which was applicable to populations as well as individuals.

Partners

• School of Biological Sciences, University of East Anglia (UEA, UK)
• Netherlands Institute for Fisheries Research (RIVO- DLO, The Netherlands)
• Centre for Environment, Fisheries and Aquaculture Science (Cefas, UK)
• Agricultural Research Centre, Department Sea Fisheries (RSZV, Belgium)
• Danish Fisheries Research Institute (DIFRES, Denmark)