Satellite Tracking Reveals the Speed Up of the Lacustrine Algal Bloom Drift in Response to Climate Change

Satellite evidence indicates a global
increase in lacustrine algal
blooms. These blooms can drift with winds, resulting in significant
changes of the algal biomass spatial distribution, which is crucial
in bloom formation. However, the lack of long-term, large-scale observational
data has limited our understanding of bloom drift. Here, we have developed
a novel method to track the drift using multi-source remote sensing
satellites and presented a comprehensive bloom drift data set for
four typical lakes: Lake Taihu (China, 2011–2021), Lake Chaohu
(China, 2011–2020), Lake Dianchi (China, 2003–2021),
and Lake Erie (North America, 2003–2021). We found that blooms
closer to the water surface tend to drift faster. Higher temperatures
and lower wind speeds bring blooms closer to the water surface, therefore
accelerating drift and increasing biomass transportation. Under ongoing
climate change, algal blooms are increasingly likely to spread over
larger areas and accumulate in downwind waters, thereby posing a heightened
risk to water resources. Our research greatly improves the understanding
of algal bloom dynamics and provides new insights into the driving
factors behind the global expansion of algal blooms. Our bloom-drift-tracking
methodology also paves the way for the development of high-precision
algal bloom prediction models.