Monitoring the Pollution of Rudnaya Bay (Sea of Japan) Based on the Heavy Metal Content of Brown Algae

Abstract

The levels of Zn, Cu, Fe, Cd, and Pb were measured in thalli of the common brown algae species Scytosiphon lomentaria, Fucus evanescens, Stephanocystis crassipes, Silvetia babingtonii, and Saccharina japonica from Rudnaya Bay and adjacent waters. These data allowed assessment of the current spatial distribution of these elements over the waters of the study region and the species-specificity of algae as indicators of heavy metal pollution of the environment. It has been established that the main source of heavy metals entering the bay waters is the small harbor in its southern part, where lead and zinc concentrates from the Dalnegorsk Mining and Processing Plant are loaded on vessels for further transportation. The estimated trace-element composition of algae was compared to that of the samples collected in 2009, which is the year of the last increase and, simultaneously, completion of the production activity of the local lead smelting plant. The results show that by 2016 the concentration of Pb in S. lomentaria collected near Cape Briner at the entrance to the bay decreased 7.4 times. The reduction in the Zn content of S. lomentaria was not as impressive: from 2009 to 2016, it decreased 1.7 times. In algae from Lidovka Bay, which is located north of Rudnaya Bay, the Zn concentration in 2016 increased 1.67 times compared to that in 2010, which is obviously explained by the growing recreational pressure on the coast of this bay.