Physical-chemical characteristics and biota structure of more than 30 freshwater rockpools of 5 islands of the Keret Archipelago (the Kandalaksha Bay, the White Sea) were estimated. The mean water temperatures are decreasing the further the islands are from the continent. pH changed from 4,06 to 10,45 permanganate oxidation -from IO to 45 mg O₂/l. Mean total phosphorus concentration (up to 180 mkg/l), density and biomass of phytoplankton up to 6,9 min cell/l and 0,45 mg/l correspondingly), Zooplankton (up to 750 ind/l and 220 mg/l), macrozoobcnthos (up to 85500 ind/m² and 220 g/m²) are on 1-2 orders higher than analogous parameters in the near-by lakes.