PELAGIC ZOOPLANKTON OF ESTUARINE WATER BODIES OF THE KAMCHATKA RIVER IN 2009-2011
Species composition, seasonal variations in the structure and quantities of pelagic zooplankton of estuarine water bodies of the Kamchatka River in 2009-2011 have been studied. Neritic crustaceous species never observed here in the middle of the 20 <sup>th</sup> century were found in the zooplankton despite no changes in the salinity of the water basins. Rotatoria constituted 60% of the total number of zooplankton. Only in winter and spring periods the abundance of crustaceous exceeded the abundance of Rotatoria in the sections with medium and strong replacement of water. The present research shows that in the years of cold summer a 1-1.5 month retardation of zooplankton's development happens. Average abundance of zooplankton in the Nerpich'e-Kultuchnoe lakes network in October of 2009, March, end of June and August of 2010 was 51, 4, 17 and 268 thousand units/m <sup>3</sup>, and the biomass was 107, 9, 47 and 321 mg/m <sup>3</sup>. At the end-August of 2011 - year of low temperatures there were 19 thousand units/m <sup>3</sup> and 38 mg/m <sup>3</sup>. Since the years 1950-1960s of the XX <sup>th</sup> century the food supply of planktivorous fishes in the lakes network has not changed.