TRANSFORMATION OF ORGANOGENIC SUBSTANCES AND RATES OF PRODUCTIONAL-DESTRUCTIONAL PROCESSES IN THE OKHOTSK SEA ECOSYSTEM

The annual dynamics of chemical and biological compouns is simulated b y an ecological model for eight sea water areas. The observations in 1 991-1993 were used in the model runs and they represent the changes of water temperature, light intensity at the water surface, parameters o f water regime in the studied sea basins and biogenic load. The simula tion results were used for the assessment of internal and external flu xes of organogenic substances and rates of productional-destructional processes in the marine ecosystem. It is shown that the pool of biogen ic substances accumulated in the surface layer during the winter perio d determines the spring development of the primary production. In the summer-fall period the phytoplankton growth is supplied by the recycli ng of biogenic substances. In the most productive water areas (near Ka mchatka peninsula and Sakhalin island) the water upwelling provides a continuous supply of organogenic substances to the upper layer and cre ates favorable conditions for the plankton growth and active substance biotransformations. During the vegetative period the integral primary production is from 37.6 to 44.6% determined by the activity of diatom s, from 28.1 to 32.4% determined by the activity of peridinium and fro m 27.2 to 30% determined by the activity of the green algae. The produ ction rate of the diatom algae and the bacterial destruction of organi c substances are comparable in the productive water areas, however in the central regions of the sea the values of the diatom production are higher. The integral value of the primary production for the upper la yer is by 59.8-66.3% higher than the bacterial destruction of organic substances.