Research Advances on the Photosynthetic Characteristics, Environmental Regulatory Mechanisms, and Ecological Applications of Harmful Algal Bloom Communities

微囊藻和鱼腥藻等蓝藻因其卓越的光合能力和多样化的适应策略，在淡水与海洋生态系统中频繁导致有害藻华(HABs)，威胁水质安全和生态平衡。本文基于近年来的相关研究，从以下4个方面综述了蓝藻光合特性及其环境响应：1) 光合色素与光能利用：探讨叶绿素a、类胡萝卜素和藻胆蛋白在有毒与无毒菌株之间的差异，并分析非光化学淬灭(NPQ)的调控机制。2) 电子传递与碳固定：阐述光合电子传递速率(ETR)、最大光合速率(Pmax)以及碳浓缩机制(CCM)在不同光照、二氧化碳浓度及营养条件下的调节过程及其对生长的影响。3) 环境因子的调控：总结光强、光谱、氮磷限制以及温度与紫外线交互作用对光合效率(Fv/Fm)、色素分布及群落竞争的影响。4) 群落动态与生态效应：分析蓝藻如何通过光利用策略驱动垂直分层与表层水华的形成，以及藻毒素释放、溶解氧波动和营养循环变动所引发的生态后果。此外，本文简要讨论了水华蓝藻在生物燃料、生物塑料(PHA)、废水净化和光生物电化学系统中的应用潜力，并展望了气候变化背景下二氧化碳浓度升高与紫外线增强对其光合特性与适应性演化的潜在影响。Bloom-forming algae, particularly cyanobacteria such as Microcystis and Oscillatoria, frequently trigger harmful algal blooms (HABs) in freshwater and marine systems due to their high photosynthetic efficiency and diverse adaptive strategies, posing serious threats to water quality and ecosystem stability. Drawing on recent literature, this review addresses their photosynthetic traits and environmental responses in four key areas: 1) Photosynthetic pigments and light utilization: a comparison of chlorophyll a, carotenoids and phycobiliproteins in toxic versus non-toxic strains, and the role of non-photochemical quenching (NPQ) in photoprotection. 2) Electron transport and carbon fixation: regulation of photosynthetic electron transport rate (ETR), maximum photosynthetic rate (Pmax) and carbon concentrating mechanisms (CCM) under varying light, CO₂ and nutrient regimes, and their effects on algal growth. 3) Environmental regulation: the impacts of light intensity, spectral quality, nitrogen/phosphorus limitation and temperature/UV interactions on photosynthetic efficiency (Fv/Fm), pigment composition and community competition. 4) Community dynamics and ecological effects: how light-use strategies drive vertical segregation and surface bloom formation, and the ecological consequences of toxin release, dissolved-oxygen fluctuations and altered nutrient cycling. In addition, we briefly review the potential biotechnological applications of bloom-forming algae in biofuel production, biodegradable plastics (PHA), wastewater treatment and photobiological electrochemical systems, and we discuss how rising CO₂ and enhanced UV under climate change may affect their photosynthetic performance and adaptive evolution.