According to the content of heavy metals Fe, Mn, Cu, Zn, Pb, Cd and Ni in brown algae Sargassum miyabei from the Peter the Great Bay of the Sea of Japan, geochemical factors were calculated. The algae geochemical anomaly index (I_GA) characterizes the degree of excess of the background concentrations of metals. The heavy metal pollution factor (F_p) is used to estimate the degree of pollution of the marine environment with heavy metals. The Peter the Great Bay has a low level of heavy metal pollution, but some parts of second-order bays, such as Amurskii Bay, Ussuriiskii Bay and Vostok Bay, have a moderate degree of pollution. The high pollution level was registed on the western coast of the Ussuriiskii Bay near the Vladivostok city landfill. Thirty percent of sampling stations were noted to have higher threshold levels of metals in the algae. These areas need to be monitored to assess their environmental status and measures should be applied to reduce the impact on the environment.