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Nwankwegu AS, Yang G, Zhang L, Xie D, Ohore OE, Adeyeye OA, Li Y, Yao X, Song Z, Yonas MW. Ecosystem anthropogenic enrichments enhance Chroococcus abundance and suppress Anabaena during cyanobacterial-dominated spring blooms in the Pengxi River, Three Gorges Reservoir, China. MARINE POLLUTION BULLETIN 2023; 193:115141. [PMID: 37295313 DOI: 10.1016/j.marpolbul.2023.115141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/12/2023]
Abstract
Taxa-specific responses to the increasing anthropogenic eutrophication offer promising insights for mitigating harmful algal blooms (HABs) in freshwaters. The present study evaluated the HABs species dynamics in response to the ecosystem anthropogenic enrichment during cyanobacterial-dominated spring HABs in the Pengxi River, Three Gorges Reservoir, China. Results show significant cyanobacterial dominance with a relative abundance (RA = 76.54 %). The ecosystem enrichments triggered shifts in the HABs community structure from Anabaena to Chroococcus, especially in the culture involving iron (Fe) addition (RA = 66.16 %). While P-alone enrichment caused a dramatic increase in the aggregate cell density (2.45 × 108 cells L-1), the multiple enrichment (NPFe) led to maximum biomass production (as chl-a = 39.62 ± 2.33 μgL-1), indicating that nutrient in conjunction with the HABs taxonomic characteristics e.g., tendency to possess high cell pigment contents rather than cell density can potentially determine massive biomass accumulations during HABs. The stimulation of growth as biomass production demonstrated by both P-alone and the multiple enrichments, NPFe indicates that although P exclusive control is feasible in the Pengxi ecosystem, it can only guarantee a short-term reduction in HABs magnitude and duration, thus a lasting HABs mitigation measure must consider a policy recommendation involving multiple nutrient management, especially N and P dual control strategy. The present study would adequately complement the concerted effort in developing a rational predictive framework for freshwater eutrophication management and HABs mitigations in the TGR and elsewhere with similar anthropogenic stressors.
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Affiliation(s)
- Amechi S Nwankwegu
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716, China; National Base of International S&T Collaboration on Water Environmental Monitoring and Simulation in Three Gorges Reservoir Region, Chongqing 400716, China; College of Environment, Hohai University, No.1 Xikang Road, Gulou District, Nanjing 210098, China
| | - Guanglang Yang
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716, China
| | - Lei Zhang
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716, China; National Base of International S&T Collaboration on Water Environmental Monitoring and Simulation in Three Gorges Reservoir Region, Chongqing 400716, China.
| | - Deti Xie
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716, China; National Base of International S&T Collaboration on Water Environmental Monitoring and Simulation in Three Gorges Reservoir Region, Chongqing 400716, China
| | - Okugbe E Ohore
- Institute of Marine Sciences, Shantou University, Shantou 515063, China
| | - Oluwafemi Adewole Adeyeye
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716, China; National Base of International S&T Collaboration on Water Environmental Monitoring and Simulation in Three Gorges Reservoir Region, Chongqing 400716, China
| | - Yiping Li
- College of Environment, Hohai University, No.1 Xikang Road, Gulou District, Nanjing 210098, China
| | - Xuexing Yao
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716, China
| | - Zenghui Song
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716, China
| | - Muhammad W Yonas
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716, China
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