Beyond hypoxia: Occurrence and characteristics of black blooms due to the decomposition of the submerged plant Potamogeton crispus in a shallow lake  

作　　者：Qiushi Shen Qilin Zhou Jingge Shang Shiguang Shao Lei Zhang Chengxin Fan 

机构地区：[1]State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences [2]University of Chinese Academy of Sciences [3]College of Hydrology and Water Resource, Hohai University

出　　处：《Journal of Environmental Sciences》2014年第2期281-288,共8页环境科学学报（英文版）

基　　金：supported by the Major National Science and Technology Programs on Water Pollution Control and Treatment (No. 2012X0713-005);the Innovation Program of the Chinese Academy of Sciences (No. KZCX2-EW-314);the 135 Project of Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences (No. NIGLAS2012135008);the National Natural ScienceFoundation of China (No. 41103033);the IndustryUniversity-Research Prospective Joint Research Projects of Jiangsu Province (No. BY2011165)

摘　　要：Organic matter-induced black blooms （hypoxia and an offensive odor） are a serious ecosystem disasters that have occurred in some large eutrophic shallow lakes in China. In this study, we investigated two separate black blooms that were induced by Potamogeton crispus in Lake Taihu, China. The main physical and chemical characteristics, including color- and odor-related substances, of the black blooms were analyzed. The black blooms were characterized by low dissolved oxygen concentration （close to 0 mg/L）, low oxidation-reduction potential, and relatively low pH of overlying water. Notably higher Fe^2＋ and ∑S2- were found in the black-bloom waters than in waters not affected by black blooms. The black color of the water may be attributable to the high concentration of these elements, as black FeS was considered to be the main substance causing the black color of blooms in freshwater lakes. Volatile organic sulfur compounds, including dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, were very abundant in the black-bloom waters. The massive anoxic degradation of dead Potamogeton crispus plants released dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, which were the main odor-causing compounds in the black blooms. The black blooms also induced an increase in ammonium nitrogen and soluble reactive phosphorus levels in the overlying waters. This extreme phenomenon not only heavily influenced the original lake ecosystem but also greatly changed the cycling of Fe, S, and nutrients in the water column.Organic matter-induced black blooms （hypoxia and an offensive odor） are a serious ecosystem disasters that have occurred in some large eutrophic shallow lakes in China. In this study, we investigated two separate black blooms that were induced by Potamogeton crispus in Lake Taihu, China. The main physical and chemical characteristics, including color- and odor-related substances, of the black blooms were analyzed. The black blooms were characterized by low dissolved oxygen concentration （close to 0 mg/L）, low oxidation-reduction potential, and relatively low pH of overlying water. Notably higher Fe^2＋ and ∑S2- were found in the black-bloom waters than in waters not affected by black blooms. The black color of the water may be attributable to the high concentration of these elements, as black FeS was considered to be the main substance causing the black color of blooms in freshwater lakes. Volatile organic sulfur compounds, including dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, were very abundant in the black-bloom waters. The massive anoxic degradation of dead Potamogeton crispus plants released dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, which were the main odor-causing compounds in the black blooms. The black blooms also induced an increase in ammonium nitrogen and soluble reactive phosphorus levels in the overlying waters. This extreme phenomenon not only heavily influenced the original lake ecosystem but also greatly changed the cycling of Fe, S, and nutrients in the water column.

关 键 词：Black bloom hypoxia submerged plant volatile organic sulfur compounds lake 

分 类 号：X524[环境科学与工程—环境工程] Q948.8[生物学—植物学]