Research progresses in algal buoyancy mechanism

LV Zhengzheng; LIU Xiaoli; LIU Lijuan; XU Zhiguang

doi:10.13984/j.cnki.cn37-1141.2025.05.028

Abstract：Algae are the most important primary producers in aquatic ecosystems.However,in recent years,harmful ecological phenomena like"water bloom"in freshwater,and"red tide","green tide"and"golden tide"in seawater have frequently been appearing,which have greatly impacted the aquatic ecosystems including lakes,ponds and oceans.The buoyancy control and regulation of these algal blooms is the key to determine their floating life and becomes an important link in the process of algal blooms.In this paper,the regulation mechanism of algal buoyancy and the latest research progress of the effects of light,nutrients,CO2 and other important water environmental factors on algal buoyancy were summarized.Some special structures of algae,such as air bags and hollow tubular bodies,provide positive buoyancy for algae when they are filled with air,while the cell ballast mainly composed of car-bohydrates can counteract the positive buoyancy.Algae float up at the lower light level,and sink at the higher light level.Nitrogen limitation reduces the buoyancy of algae more significantly,compared with phosphorus limitation.The buoyancy of algae rises at high CO2 concentration and high temperature.Therefore,the vertical position of algae in water is comprehensively affected by multiple environmental factors.In this review,we summarized the research progresses in algal buoyancy,provided some theo-retical references for further prevention and control of harmful algal blooms.