Introduction
Despite the apparent uniformity and homogeneity of the water masses in the sea, there are areas similar to terrestrial
biogeochemical provinces. Abnormalities or deviations from the background in the environment and biota stipulated by the
geochemical features of these zones are not as pronounced as in the sea. They appear not only in the existence of endemic diseases
caused by changes in the mineral metabolism of terrestrial organisms but also in distinctive biocenoses and mineral compositions
of organisms. In the sea, the difference between the concentrations of elements in a biogeochemical province and beyond it may
not be as sharp as on land because of the nature of the environment.
The impact zones of anthropogenic origin, established in coastal areas, are well known. They are caused by technogenic pollution,
which creates an abnormal concentration of a number of elements and compounds.
The impact zones of natural-anthropogenic origin are estuarine river zones, which reflect the nature of the drained soils and the
character of polluted wastewater in the solid and liquid effluent to the sea.