Primary production in relation to climatic changes in the Barents Sea

The Barents Sea is charaeterized by extreme environmental conditions that have considerable infiuence on the biological development, especially during spring. Based on physical and biological observations obtained during a six years period and a mathematical model for phyto- and zooplankton, we have examined the biological developmen t in relation to the climatie changes which occurred during this period. The main effect of climatic variations is in determining the timing of the phytoplankton spring bloom in the different water masses, Warm years are characterized by a delayed phytoplankton bloom and an earlier stage development of zooplankton in Atlantic waters, apparently resulting in a higher proportion of the spring bloom being grazed and channelized to higher pelagic trophic levels. Cold years, on the contrary, can result In earller ice-edge spring bloom and late development of zooplankton , eausing a signlfieant portion of the primary production to be left ungrazed and to sediment out to the deeper water layers and the bottom