Data are given on the Pu content in the surface and bottom layers of water
and bottom sediments of the Kara Sea and other Arctic seas. The contributio
n of local contamination sources to the radioactive contamination of the Ka
ra Sea water area with plutonium is proved to be insignificant, and the tot
al concentration of plutonium isotopes (238-240)pu in seawater and bottom s
ediments is caused essentially by the global fallout.