The Assessment of Phytoplankton Dynamics in Two Reservoirs in Southern Africa with Special Reference to Water Abstraction for Inter-Basin Transfers and Potable Water Production
Toxic phytoplankton in the aquatic ecosystems are dynamic, affecting water quality. It remains unclear as to how possible toxic phytoplankton assemblages vary vertically and temporally in Swakoppoort and Von Bach dams, located in a dry subtropical desert region in central Namibia. The following vari...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-11-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/13/21/3045 |
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| author | Johannes Sirunda Paul Oberholster Gideon Wolfaardt Marelize Botes Christoff Truter |
| author_facet | Johannes Sirunda Paul Oberholster Gideon Wolfaardt Marelize Botes Christoff Truter |
| author_sort | Johannes Sirunda |
| collection | DOAJ |
| description | Toxic phytoplankton in the aquatic ecosystems are dynamic, affecting water quality. It remains unclear as to how possible toxic phytoplankton assemblages vary vertically and temporally in Swakoppoort and Von Bach dams, located in a dry subtropical desert region in central Namibia. The following variables were analyzed: pH, Secchi depths, turbidity, water temperature, total phosphorus, orthophosphate, chlorophyll-<i>a</i>, phytoplankton cells, and water depths. Cyanobacteria dominated the phytoplankton community in the autumn, winter and spring (dry) and summer (wet) seasons, at all the depth ranges in both dams. <i>Microcystis</i> dominated the vertical and temporal dynamics, followed by <i>Dolichospermum</i>. In the dry seasons, higher cyanobacteria cell numbers were observed in comparison to the rainy season in both dams. Spring blooms of cyanobacteria were evident in the Von Bach Dam while autumn and spring cyanobacteria blooms were observed in the Swakoppoort Dam. In the Swakoppoort Dam, the preferable depth ranges for toxic cyanobacteria species were at 5 to 10 m while in the Von Bach Dam at 0 to 5 m range. The findings of the current study indicate that the traditional selective withdrawal of water in the two dams should be performed with vertical and temporal dynamics of possible toxic cyanobacteria accounted for to aid the abstraction of water with the lowest possible toxic phytoplankton numbers, which could lower the public health risk. |
| first_indexed | 2024-03-10T05:48:52Z |
| format | Article |
| id | doaj.art-3797e993b6ce4a3f845bcf2f00bd3dc1 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-10T05:48:52Z |
| publishDate | 2021-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-3797e993b6ce4a3f845bcf2f00bd3dc12023-11-22T21:54:29ZengMDPI AGWater2073-44412021-11-011321304510.3390/w13213045The Assessment of Phytoplankton Dynamics in Two Reservoirs in Southern Africa with Special Reference to Water Abstraction for Inter-Basin Transfers and Potable Water ProductionJohannes Sirunda0Paul Oberholster1Gideon Wolfaardt2Marelize Botes3Christoff Truter4Research and Development Department, Namibia Water Corporation, 176 Iscor Street, Northern Industrial Area, Windhoek 13389, NamibiaCentre for Environmental Management, Faculty of Natural and Agricultural Sciences, University of the Free State, Bloemfontein 9300, South AfricaFaculty of Science, Stellenbosch University Water Institute, Stellenbosch University, Matieland 7600, South AfricaFaculty of Science, Stellenbosch University Water Institute, Stellenbosch University, Matieland 7600, South AfricaDepartment of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Pretoria 0110, South AfricaToxic phytoplankton in the aquatic ecosystems are dynamic, affecting water quality. It remains unclear as to how possible toxic phytoplankton assemblages vary vertically and temporally in Swakoppoort and Von Bach dams, located in a dry subtropical desert region in central Namibia. The following variables were analyzed: pH, Secchi depths, turbidity, water temperature, total phosphorus, orthophosphate, chlorophyll-<i>a</i>, phytoplankton cells, and water depths. Cyanobacteria dominated the phytoplankton community in the autumn, winter and spring (dry) and summer (wet) seasons, at all the depth ranges in both dams. <i>Microcystis</i> dominated the vertical and temporal dynamics, followed by <i>Dolichospermum</i>. In the dry seasons, higher cyanobacteria cell numbers were observed in comparison to the rainy season in both dams. Spring blooms of cyanobacteria were evident in the Von Bach Dam while autumn and spring cyanobacteria blooms were observed in the Swakoppoort Dam. In the Swakoppoort Dam, the preferable depth ranges for toxic cyanobacteria species were at 5 to 10 m while in the Von Bach Dam at 0 to 5 m range. The findings of the current study indicate that the traditional selective withdrawal of water in the two dams should be performed with vertical and temporal dynamics of possible toxic cyanobacteria accounted for to aid the abstraction of water with the lowest possible toxic phytoplankton numbers, which could lower the public health risk.https://www.mdpi.com/2073-4441/13/21/3045cyanobacteriawater qualitydepthdynamiclakediversity |
| spellingShingle | Johannes Sirunda Paul Oberholster Gideon Wolfaardt Marelize Botes Christoff Truter The Assessment of Phytoplankton Dynamics in Two Reservoirs in Southern Africa with Special Reference to Water Abstraction for Inter-Basin Transfers and Potable Water Production Water cyanobacteria water quality depth dynamic lake diversity |
| title | The Assessment of Phytoplankton Dynamics in Two Reservoirs in Southern Africa with Special Reference to Water Abstraction for Inter-Basin Transfers and Potable Water Production |
| title_full | The Assessment of Phytoplankton Dynamics in Two Reservoirs in Southern Africa with Special Reference to Water Abstraction for Inter-Basin Transfers and Potable Water Production |
| title_fullStr | The Assessment of Phytoplankton Dynamics in Two Reservoirs in Southern Africa with Special Reference to Water Abstraction for Inter-Basin Transfers and Potable Water Production |
| title_full_unstemmed | The Assessment of Phytoplankton Dynamics in Two Reservoirs in Southern Africa with Special Reference to Water Abstraction for Inter-Basin Transfers and Potable Water Production |
| title_short | The Assessment of Phytoplankton Dynamics in Two Reservoirs in Southern Africa with Special Reference to Water Abstraction for Inter-Basin Transfers and Potable Water Production |
| title_sort | assessment of phytoplankton dynamics in two reservoirs in southern africa with special reference to water abstraction for inter basin transfers and potable water production |
| topic | cyanobacteria water quality depth dynamic lake diversity |
| url | https://www.mdpi.com/2073-4441/13/21/3045 |
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