Functional trait-based phytoplankton biomass and assemblage analyses in the pre-growing season for comprehensive algal bloom risk assessment

• Published in: Water research (Oxford) 2024-06, Vol.257, p.121755-121755, Article 121755
• Main Authors: Zhang, Chengxiang, Lei, Guangchun, Zhao, Fanxuan, Chen, Kebing, Zhang, Chenchen, Lu, Cai, Luo, Qiyong, Song, Jianying, Chen, Kun, Ye, Jingxu, Yi, Yujun
• Format: Article
• Language: English
• Subjects: Algal bloom risk assessment; Biomass; China; Ecosystem; Environmental Monitoring - methods; Eutrophication; Functional trait; Hazard; Lake ecosystem; Lakes; Phytoplankton; Risk Assessment; Seasons
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2024.121755

•Environmental drivers and characters of algal blooms in Dongting Lake were studied.•Algal bloom potential was low, but functional traits suggested toxic hazards.•NH4+ was the key factor for phytoplankton biomass and toxigenicity.•Sensitivity of zooplankton to environmental factors inhibited phytoplankton control.•Warm winters may exacerbate algal bloom risk. Algal bloom (AB) risk assessment is critical for maintaining ecosystem health and human sustainability. Previous AB risk assessments have focused on the potential occurrence of ABs and related factors in the growing season, whereas their hazards, especially in the pre-growing season, have attracted less attention. Here, we performed a comprehensive AB risk assessment, including water trophic levels, phytoplankton biomass, functional trait-based assemblages, and related environmental factors, in the pre-growing season in Dongting Lake, China. Although mesotrophic water and low phytoplankton biomass suggested low AB potential, toxic taxa, which constituted 13.28% of the phytoplankton biomass, indicated non-negligible AB hazards. NH4+ and water temperature were key factors affecting phytoplankton motility and toxicity. Our study establishes a new paradigm for quantitative AB risk assessment, including both potential AB occurrence and hazards. We emphasize the importance of phytoplankton functional traits for early AB warning and NH4+ reduction for AB control in the pre-growing season. [Display omitted]