Geochemistry of the water column of southern lake Baikal during 1967-2005

At present, when the influence of human economic activity is progressively increasing, significant attention is devoted to the state of water ecosystems. All researchers engaged in these problems agree that the state of the water system (pollution and eutrophication) can only be estimated on the basis of long-term researches. Systemic monitoring (at least once per month) of ionic components (Ca2+, Mg2+, Na+, K+, bicarbonates, sulfates, and chlorides) in unfiltered water of Lake Baikal and its tributaries had been carried out under the supervision of Votintsev since 1947.
Based on the analysis of systematic data on trophic components obtained during 1965-2005, we tried to estimate the present-day trophic status of the pelagic zone in the lake, define the trend of long-term changes of trophic components and understand the reasons of the distortion of cyclicity in the development of spring diatom algae, which create a favorable environment in any water basin. It should be noted that the station near Cape Polovinnyi is located 20 km away from the town of Baikal'sk. Wastewaters of the Baikal'sk pulp and paper mill is the main source of dioxins and furans in Baikal. Based on the significant difference between sulfate contents in wastewaters of the plant (>300 mg/l), tributaries of Baikal (7.5 mg/l), and waters in the southern part of the lake (3.9 mg/l), we defined the following periods: (i) period of natural seasonal patterns until 1967-1968 (prior to putting the Baikal'sk Mill into operation; (ii) period of weak anthropogenic pollution (1969-1985); and (iii) period of strong anthropogenic pollution since 1986.

当前，伴随人类经济活动的影响持续加深，水生态系统的健康状态已受到学界的广泛关注。所有投身相关研究的学者均达成共识：水系统的状态（涵盖污染与富营养化）仅能依托长期观测研究开展评估。自1947年起，在沃京采夫（Votintsev）的主持下，研究团队对贝加尔湖（Lake Baikal）及其支流的未过滤水体中的离子组分（Ca²+、Mg²+、Na+、K+、碳酸氢盐、硫酸盐及氯化物）开展了系统性监测，监测频次至少为每月1次。基于1965-2005年间获取的营养组分系统性监测数据，本研究尝试评估该湖泊敞水带（pelagic zone）当前的营养状态，明确营养组分的长期变化趋势，并解析春季硅藻（diatom algae）发育周期的畸变成因——这类硅藻可在各类水体中构建适宜的生存环境。需特别指出的是，波洛文内角（Cape Polovinnyi）附近的监测站点距离贝加尔斯克镇（Baikal'sk）约20公里。贝加尔斯克纸浆造纸厂的废水是贝加尔湖中二噁英（dioxins）与呋喃（furans）的主要排放来源。结合该工厂废水（硫酸盐浓度>300 mg/L）、贝加尔湖支流（硫酸盐浓度7.5 mg/L）及湖南部水域（硫酸盐浓度3.9 mg/L）间的硫酸盐含量显著差异，本研究将观测时段划分为三个阶段：(i) 1967-1968年之前的自然季节性变化阶段（即贝加尔斯克工厂投产前）；(ii) 1969-1985年的轻度人为污染阶段；(iii) 1986年起的重度人为污染阶段。