Influence of light availability on the specific density, size and sinking loss of Anabaena flos-aquae and Scenedesmus obliquus
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Harmful algal blooms in eutrophic waters pose a serious threat to freshwater ecosystems and human health. In-situ light availability control is one of the most commonly used technologies to suppress algae in lakes and reservoirs. To develop a better understanding of the effects of light on algal growth, specific density, colony size and sinking loss, Anabaena flos-aquae (cyanobacteria) and Scenedesmus obliquus (green algae) were evaluated in varying light scenarios. The results showed that the specific density and colony size of these two species varied during growth, and there were obvious differences among the light scenarios. At the end of exponential phase, S. obliquus incubated under light-limited condition maintained a higher specific density and formed larger aggregates, whereas A. flos-aquae formed a longer filament length. Both species exhibited higher sinking loss rates with lower light availability. These results implied that the sinking loss rate was not always constant but should be considered as a variable response to the change of light availability, and in-situ light availability control might result in a significant increase of the sinking loss of algae due to the change of size and specific density, thereby further affecting the algal biomass in the water column.
Keywordspecific density size light availability control sinking loss
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- Diehl S, Berger S, Ptacnik R, Wild A. 2002. Phytoplankton, light, and nutrients in a gradient of mixing depths: field experiments. Ecology, 83 (2): 399–411, https://doi.org/10.1890/0012-9658(2002)083[0399:PLANIA]2.0.CO;2.CrossRefGoogle Scholar
- Huisman J. 1999. Population dynamics of light-limited phytoplankton: microcosm experiments. Ecology, 80 (1): 202–210, https://doi.org/10.1890/0012-9658(1999)080[0202:PDOLLP]2.0.CO;2.CrossRefGoogle Scholar
- Jungo E, Visser P M, Stroom J, Mur L R. 2001. Artificial mixing to reduce growth of the blue-green alga Microcystis in Lake Nieuwe Meer, Amsterdam: an evaluation of 7 years of experience. Water Science & Technology: Water Supply, 1 (1): 17–23.Google Scholar
- Kojima S. 2000. Corroborating study on algal control by partial shading of lake surface. Main-Water and Wastewater, 42 (5): 5–12. (in Japanese)Google Scholar
- Li M, Gao L, Lin L. 2015. Specific growth rate, colonial morphology and extracellular polysaccharides (EPS) content of Scenedesmus obliquus grown under different levels of light limitation. Annales de Limnologie-International Journal of Limnology, 51 (4): 329–334, https://doi.org/10.1051/limn/2015033.CrossRefGoogle Scholar
- Reynolds C S. 2006. Entrainment and distribution in the pelagic (Chapter 2). In: Reynolds C S ed. The Ecology of Phytoplankton. Cambridge University Press, Cambridge. p.38–92.Google Scholar
- WolffD A. 1975. The separation of cells and subcellular particles by colloidal silica density gradient centrifugation. In: Prescott D M ed. Methods in Cell Biology. Academic Press, United States. p.85–104.Google Scholar