IMPACT OF INTERANNUAL VARIABILITY IN HYDRODYNAMIC CIRCULATION ON EGG AND LARVAL TRANSPORT OF PLAICE PLEURONECTES-PLATESSA L IN THE SOUTHERNNORTH-SEA

A realistic 2D circulation model of the southern North Sea was applied to simulate the interannual variability in dispersal (advection and d iffusion) of plaice Pleuronectes platessa L. eggs and larvae from the spawning area in the Southern Eight of the North Sea towards the Dutch coastal nursery areas. The model is driven with daily varying current fields, which are the result of driving a general hydrodynamical mode l with realistic tidal and meteorological (wind) forcing for the perio d 1974-1981. Model simulations of plaice egg and larval transport are compared with observed larval concentrations near coastal nursery area s (Delta area and Wadden Sea). The model simulations show that: (1) th e interannual variability in transport is large and of the same order as the year-to-year variations observed in larval concentrations near the nursery areas; (2) the interannual variability increases with incr easing distance from the spawning area; (3) for the years in which lar val estimates were available, the model predictions were positively co rrelated with observed estimates for the Marsdiep tidal inlet. This su ggests that the variability in circulation patterns during the early p elagic stages in the open sea might be a key factor in determining yea r-class strength of plaice. (C) 1998 Elsevier Science B.V. All rights reserved.