Response of cyanobacterial blooms to climate warming: evidence from satellite observations and long-term trends in Lake Taihu in China

There is still a lack of fundamental understanding of how climate warming drives the expansion of cyanobacterial blooms in freshwater ecosystems. This paper explores the impacts of climate warming on cyanobacterial blooms on the basis of long-term (2003–2022) satellite images and meteorological observation data, with Lake Taihu in China taken as an example. These results indicate that over the past two decades, with climate warming, cyanobacterial blooms have significantly expanded. For every 1 °C increase in the annual average temperature, the cumulative area of cyanobacterial blooms will increase by approximately 5,377 km2. The date of the first observed blooms is negatively correlated (R = -0.73) with the average winter–spring temperature, which increased by 39 days per decade on average. The date of the last observed blooms is positively correlated (R = 0.6) with the average temperature from November–December, with a delay of 18 days per decade. Furthermore, the temperature response curve of cyanobacterial blooms derived from satellites also conforms to an “S-shaped” pattern. The evidence provided by this study demonstrates that climate warming promotes the expansion of cyanobacterial blooms in this lake and that the synergistic effects of climate change should be incorporated into strategies for controlling cyanobacterial blooms.