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Wang M, Bian W, Qi X, He D, Lu H, Yang L. Cycles of solar ultraviolet radiation favor periodic expansions of cyanobacterial blooms in global lakes. WATER RESEARCH 2024; 255:121471. [PMID: 38503183 DOI: 10.1016/j.watres.2024.121471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 02/12/2024] [Accepted: 03/12/2024] [Indexed: 03/21/2024]
Abstract
Global warming and eutrophication are known to increase the prevalence of cyanobacterial blooms, posing a severe threat to the ecological stability and sustainability of water bodies. The long-term (over an annual time frame) effect of UV radiation on cyanobacterial blooms in lakes are rarely discussed though the substantial effects of high-intensity UV radiation on the growth inhibition of marine phytoplankton were studied. Here, we employed the datasets on surface solar UV radiation, nitrogen and phosphorus concentrations, and the annual scales and frequencies of cyanobacterial blooms in lakes across long-term spatial scales to probe the relationship of UV radiation with cyanobacterial blooms. The results indicated that enhanced solar UV radiation may unintentionally stimulate cyanobacterial growth and favor the expansions of cyanobacterial blooms in lakes around the world. The fluctuating UV radiation significantly affects the annual scales of cyanobacterial blooms in both eutrophic and oligotrophic lakes. Solar UV radiation enhances the positive impact of rising phosphorus levels on cyanobacterial blooms because UV radiation prompts the synthesis of polyphosphate in cyanobacteria cells, which helps cyanobacteria to alleviate the stress of UV light. The scales of cyanobacterial blooms are significantly impacted by solar UV radiation intensities as opposed to the annual frequency of cyanobacterial blooms. Furthermore, solar UV radiation fluctuation with a 9-year period over a 14-year main cycles significantly affects the periodicities of cyanobacterial blooms in global lakes, which provides a basis for predicting the peak value of the scales of cyanobacterial blooms in lakes. These findings opened up new avenues of inquiry into the mechanism and management strategies of cyanobacterial blooms in lakes worldwide.
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Affiliation(s)
- Mengmeng Wang
- State Key Laboratory of Pollution Control and Research Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Wenbin Bian
- State Key Laboratory of Pollution Control and Research Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Ximeng Qi
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China
| | - Di He
- State Key Laboratory of Pollution Control and Research Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Hao Lu
- Nanjing Hydraulic Research Institute, Nanjing 210029, China
| | - Liuyan Yang
- State Key Laboratory of Pollution Control and Research Reuse, School of Environment, Nanjing University, Nanjing 210023, China.
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Helbling EW, Villafañe VE, Narvarte MA, Burgueño GM, Saad JF, González RA, Cabrerizo MJ. The impact of extreme weather events exceeds those due to global-change drivers on coastal phytoplankton assemblages. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170644. [PMID: 38320708 DOI: 10.1016/j.scitotenv.2024.170644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/28/2024] [Accepted: 01/31/2024] [Indexed: 02/13/2024]
Abstract
Extreme wind and rainfall events have become more frequent phenomena, impacting coastal ecosystems by inducing increased mixing regimes in the upper mixed layers (UML) and reduced transparency (i.e. browning), hence affecting phytoplankton photosynthesis. In this study, five plankton assemblages from the South Atlantic Ocean, from a gradient of environmental variability and anthropogenic exposure, were subjected to simulated extreme weather events under a global change scenario (GCS) of increased temperature and nutrients and decreased pH, and compared to ambient conditions (Control). Using multiple linear regression (MLR) analysis we determined that evenness and the ratio of diatoms/ (flagellates + dinoflagellates) significantly explained the variations (81-91 %) of the photosynthesis efficiency (i.e. Pchla/ETRchla ratio) for each site under static conditions. Mixing speed and the optical depth (i.e. attenuation coefficient * depth, kdz), as single drivers, explained 40-76 % of the variability in the Pchla/ETRchla ratio, while GCS drivers <9 %. Overall, assemblages with high diversity and evenness were less vulnerable to extreme weather events under a GCS. Extreme weather events should be considered in global change studies and conservation/management plans as even at local/regional scales, they can exceed the predicted impacts of mean global climate change on coastal primary productivity.
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Affiliation(s)
- E Walter Helbling
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103 Rawson, Chubut, Argentina.
| | - Virginia E Villafañe
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103 Rawson, Chubut, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Maite A Narvarte
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni & Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, 8520 San Antonio Oeste, Río Negro, Argentina
| | - Giuliana M Burgueño
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni & Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, 8520 San Antonio Oeste, Río Negro, Argentina
| | - Juan F Saad
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni & Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, 8520 San Antonio Oeste, Río Negro, Argentina
| | - Raúl A González
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni & Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, 8520 San Antonio Oeste, Río Negro, Argentina
| | - Marco J Cabrerizo
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103 Rawson, Chubut, Argentina; Departamento de Ecología, Facultad de Ciencias, Campus de Fuentenueva s/n & Instituto Universitario de Investigación del Agua, Universidad de Granada, 18071 Granada, Spain
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