ESTIMATION OF NEW PRODUCTION IN THE NORTH-SEA - CONSEQUENCES FOR TEMPORAL AND SPATIAL VARIABILITY OF PHYTOPLANKTON

By coupling knowledge of oceanographic processes and phytoplankton res ponses to light and nutrient availability, we estimate a total potenti al new production for the North Sea of approximately 15.6 x 10(6) t C year(-1). In a typical year, about 40% of this production will be asso ciated with the spring bloom in the surface waters of the seasonally s tratified central and northern regions. About 40% is predicted to occu r in the coastal waters while the remaining new production is predicte d to take place in subsurface chlorophyll peaks occurring in associati on with fronts during summer months. By considering inter-annual varia tion in heat, wind, and nutrient availability (light and tidal energy input are treated as non-varying from year to year), the inter-annual variability in the new production in different regions is estimated. T he analysis indicates that new production in the coastal waters may ha ve increased by about 25% in recent decades. (C) 1998 International Co uncil for the Exploration of the Sea.