作者：Wei, C., Li, D., Li, H., Huang, Y., Guo, X., Zhang, H., Deng, D., Liu, D. & Yang, Z.

Harmful algal blooms (HABs) threaten global freshwater ecosystems, yet reliable early warning indicators remain elusive, as traditional nutrient and temperature models often fail to capture the metabolic transition to explosive proliferation. This study investigates multi-component dissolved gas dynamics (O2, CO2, N2, Ar, and TDG) as novel early warning indicators that directly reflect algal physiological activity rather than static environmental conditions, thereby bridging the gap between favorable conditions and bloom realization. We conducted continuous in-situ monitoring in the Pengxi River of the Three Gorges Reservoir, China, across five periods between 2023 and 2024. The results revealed three sequential gas-based indicators reflecting bloom progression. First, the Argon-Oxygen (Ar-O2) correlation shifted from positive to negative, signaling the transition to algaefavorable conditions where photosynthetic oxygen production overrides temperature-driven solubility controls. Second, Photosynthetic Quotient (PQ) spikes exceeding 1.5 revealed cryptic subsurface algal accumulation before significant surface biomass appeared. Third, Total Dissolved Gas (TDG) supersaturation exceeding 105% marked a biophysical tipping point where micro-bubble formation accelerated bloom intensification through buoyancy-mediated aggregation. Unlike static environmental parameters, these gas dynamics directly reflect algal physiological activity and spatial distribution. Critically, the PQ-spike stage defines the optimal intervention window, enabling reservoir operations to disrupt subsurface accumulation before surface manifestation and TDG-driven escalation. Integrating these dissolved gas patterns into existing frameworks bridges the gap between environmental favorability and actual bloom occurrence. Our mechanism-based framework offers a transformative pathway for proactive HAB management in reservoir systems worldwide under intensifying climate pressures.

有害藻华威胁着全球淡水生态系统，但可靠的早期预警指标仍难以确定，因为传统的营养盐与温度模型往往无法捕捉到藻类向爆发性增殖转变的代谢过程。本研究探究了多组分溶解气体动态（O₂、CO₂、N₂、Ar 和 TDG）作为新型早期预警指标的可能性，这些指标直接反映藻类的生理活动而非静态环境条件，从而弥合了有利条件与实际藻华发生之间的鸿沟。我们于 2023 年至 2024 年期间，在中国三峡库区澎溪河开展了五个时段的连续原位监测。结果揭示了反映藻华发展过程的三个相继出现的气体指标。第一，氩-氧相关性由正转负，标志着向藻类有利条件的过渡，此时光合产氧已压过温度驱动的溶解度控制。第二，光合商峰值超过 1.5，揭示了表层生物量明显出现之前水体次表层隐伏的藻类聚集。第三，总溶解气体过饱和超过 105%，标志着一个生物物理临界点，此时微气泡的形成通过浮力介导的聚集作用加速了藻华的加剧。与静态环境参数不同，这些气体动态直接反映了藻类的生理活动和空间分布。尤为关键的是，光合商峰值阶段定义了最佳干预窗口，使得水库调度能够在表层显现和总溶解气体驱动的升级之前，就打破次表层的藻类聚集。将这些溶解气体模式整合到现有框架中，可以弥合环境适宜性与实际藻华发生之间的差距。我们提出的基于机制的框架，为全球水库系统在日益加剧的气候压力下实现有害藻华的主动管理提供了一条变革性路径。

（来源：Water Research 2026  DOI: 10.1016/j.watres.2026.125685）