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Feedback regulation of surface scum formation and persistence by self-shading of Microcystis colonies: Numerical simulations and laboratory experiments
- Source :
- Water research. 194
- Publication Year :
- 2020
-
Abstract
- Light availability is an important driver of algal growth and for the formation of surface blooms. The formation of Microcystis surface scum decreases the transparency of the water column and influences the vertical distribution of light intensity. Only few studies analysed the interactions between the dynamics of surface blooms and the light distribution in the water column. Particularly the effect of light attenuation caused by Microcystis colonies (self-shading) on the formation of surface scum has not been explored. In the present study, we simulate the effect of variable cell concentration of Microcystis colonies on the vertical distribution of light in the water column based on experimental estimates of the extinction coefficient of Microcystis colonies. The laboratory observations indicated that higher cell concentration of Microcystis enhance the light attenuation in water column and promotes surface scum formation. We extended an existing model for the light-driven migration of Microcystis by introducing the effect of self-shading and simulated the dynamics of vertical migration for different cell concentrations and different colonial morphologies. The simulation results show that high cell concentrations of Microcystis promote surface scum formation, as well as its persistence throughout diel photoperiods. Large and tight Microcystis colonies facilitate scum formation, while small and loose colonies increase scum stability and persistence. This study reveals a positive feedback regulation of Microcystis surface scum formation and stability by self-shading and provides novel insights into the underlying mechanisms.
- Subjects :
- Environmental Engineering
Microcystis
0208 environmental biotechnology
Soil science
02 engineering and technology
010501 environmental sciences
01 natural sciences
Feedback regulation
Feedback
Water column
Waste Management and Disposal
Diel vertical migration
0105 earth and related environmental sciences
Water Science and Technology
Civil and Structural Engineering
biology
Chemistry
Ecological Modeling
Algal growth
Water
Cell concentration
biology.organism_classification
Pollution
020801 environmental engineering
Light intensity
Shading
Laboratories
Subjects
Details
- ISSN :
- 18792448
- Volume :
- 194
- Database :
- OpenAIRE
- Journal :
- Water research
- Accession number :
- edsair.doi.dedup.....372771d3a629fb026e040b9c84c99ad0