Benthic foraminifera in deep trenches of the Kara Sea and the relation of <Emphasis Type="Italic">Saccorhiza ramosa</Emphasis> (Brady) to the distribution of natural radionuclides

The abundance and structure of the foraminifera community have been investigated. The role of agglutinating and secreting species in bottom sediments of the deep trenches of the Kara Sea has been studied. It has been found that the abundance and dominance of the agglutinated foraminifera Saccorhiza ramosa depend on the depth of the sea and are related to the genetic type of origin of such sediments. A correlation has been revealed between the distribution of S. ramosa and the concentrations of natural radionuclides (²²⁶Ra, ²³²Th, and ²¹⁰Pb) in bottom sediments. The degree of dominance of S. ramosa in the community of benthic foraminifera increases along with natural radioactivity.