Materials and Methods
Bottom sediment samples from the watercourses and tailing ponds were collected during research expeditions by employees of the Sikhote-Alin Nature Reserve from August 2011 to October 2012. Sampling was performed on the perimeter of the Sikhote-Alin Reserve at the territories of the closed mining complexes Lysogorskiy (Pravaya Pritochnaya River, Kolumbe River basin) and Tayozhniy (Dalnaya River, Obilnaya River basin) and sealed off gold and silver mining complex Serebryaniy (Zolotoy Stream, Tayozhnaya River basin) (Fig. 1). To determine the background concentrations of heavy metals, samples of the bottom sediments were taken at the territory of the reserve (rivers Tayozhnaya, Zabolochennaya, Yasnaya, Serebryanka, Golubichnaya and Dzhigitovka).