Taihu Basin Monitoring Center of Hydrology and Water Resources, Wuxi 214024, China; Key Laboratory of Taihu Basin Water Resources Research and Management of Ministry of Water Resources, Wuxi 214024, China.
Taihu Basin Monitoring Center of Hydrology and Water Resources, Wuxi 214024, China; Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
Harmful Algae. 2024 Sep;138:102703. doi: 10.1016/j.hal.2024.102703. Epub 2024 Jul 31.
The proliferation of filamentous cyanobacteria in lakes can result in the generation of odor-causing compounds, predominantly 2-methylisoborneol (2-MIB), which pose odor-related challenges. In an effort to elucidate the spatiotemporal dynamics of 2-MIB and related influencing factors in East Lake Taihu, monthly investigations were undertaken from April 2022 to March 2023. In addition to the monthly survey, a whole-lake survey was conducted during the high-temperature period from July to September. The monthly survey revealed a distinct unimodal fluctuation in the concentration of 2-MIB in East Lake Taihu, with an average concentration at 297.0 ng/L during the high-temperature period. During the high-temperature period, the filamentous cyanobacterial communities detected in East Lake Taihu consisted primarily of species belonging to genera Leptolyngbya, Oscillatoria, Planktothricoides, and Pseudanabaena. However, no significant correlations were found between their densities and 2-MIB concentration. In addition, the mic gene was predominantly detected in genera Pseudanabaena and Planktothricoides, with the latter being the primary contributor to 2-MIB production. Furthermore, a succession of cyanobacteria capable of producing 2-MIB was detected, with water temperature and radiation intensity being identified as the primary driving factors. The temporal variation of 2-MIB concentration within East Lake Taihu during the whole year was primarily modulated by factors such as water temperature, water transparency, dissolved oxygen, and chlorophyll-a. During the high-temperature period, the 2-MIB concentration in the alga-dominated zone of East Lake Taihu was approximately 1.7 times greater than that in the macrophyte-dominated zone, with nutrient and transparency being identified as the main influencing factors. Consequently, our findings are of great significance for monitoring the sources and variation of 2-MIB in shallow lakes, providing a scientific foundation and theoretical guidance for odor management.
湖泊中丝状蓝藻的过度繁殖会导致产生气味化合物，主要是 2-甲基异莰醇（2-MIB），这会带来与气味相关的挑战。为了阐明太湖东部 2-MIB 及其相关影响因素的时空动态，我们从 2022 年 4 月至 2023 年 3 月进行了每月调查。除了每月调查外，我们还在 7 月至 9 月的高温期间进行了全湖调查。每月调查显示，太湖东部 2-MIB 浓度呈明显的单峰波动，高温期平均浓度为 297.0ng/L。在高温期间，太湖中检测到的丝状蓝藻群落主要由 Leptolyngbya、Oscillatoria、Planktothricoides 和 Pseudanabaena 属的物种组成。然而，它们的密度与 2-MIB 浓度之间没有发现显著相关性。此外，mic 基因主要在 Pseudanabaena 和 Planktothricoides 属中被检测到，后者是 2-MIB 产生的主要贡献者。此外，还检测到一系列能够产生 2-MIB 的蓝藻，水温和辐射强度被确定为主要驱动因素。太湖全年 2-MIB 浓度的时间变化主要受水温、水透明度、溶解氧和叶绿素-a 等因素的调节。在高温期间，太湖藻类优势区的 2-MIB 浓度约为大型植物优势区的 1.7 倍，营养物质和透明度被确定为主要影响因素。因此，我们的发现对于监测浅水湖泊中 2-MIB 的来源和变化具有重要意义，为气味管理提供了科学基础和理论指导。
