The work is devoted to the analysis of the distribution of one of the priority pollutants of our time - mercury in the bottom sediments of the White Sea and the rivers of its basin. Modern studies show that concentrations of highly toxic to living organisms of mercury and its compounds in distant regions of the Arctic and Subarctic are on average three times higher than in the pre-industrial era. Behavior of mercury in conditions of water ecosystems of the Subarctic region began to be investigated by SFedU staff under the guidance of Professor Fedorov Yu.A. in 2004. During this time, the spatial and vertical distribution of mercury in the bottom sediments was studied for the first time in the region, zoning of bottom sediments was carried out according to Hg levels, river-sea sections were studied, and the work of marginal river filters in the White Sea basin was described, background mercury levels in the bottom sediments of the sea and estuary.