Influence of cyanobacterial blooms and environmental variation on zooplankton and eukaryotic phytoplankton in a large, shallow, eutrophic lake in China

2021 ◽  
Vol 773 ◽  
pp. 145421
Author(s):  
Kun Zhao ◽  
Lizhu Wang ◽  
Qingmin You ◽  
Yangdong Pan ◽  
Tengteng Liu ◽  
...  
Hydrobiologia ◽  
2003 ◽  
Vol 506-509 (1-3) ◽  
pp. 781-787 ◽  
Author(s):  
Kasper Reitzel ◽  
Jonas Hansen ◽  
Henning S. Jensen ◽  
Frede Ø. Andersen ◽  
Kjeld S. Hansen

2016 ◽  
Vol 76 (s1) ◽  
Author(s):  
Mariano Bresciani ◽  
Claudia Giardino ◽  
Rosaria Lauceri ◽  
Erica Matta ◽  
Ilaria Cazzaniga ◽  
...  

Cyanobacterial blooms occur in many parts of the world as a result of entirely natural causes or human activity. Due to their negative effects on water resources, efforts are made to monitor cyanobacteria dynamics. This study discusses the contribution of remote sensing methods for mapping cyanobacterial blooms in lakes in northern Italy. Semi-empirical approaches were used to flag scum and cyanobacteria and spectral inversion of bio-optical models was adopted to retrieve chlorophyll-a (Chl-a) concentrations. Landsat-8 OLI data provided us both the spatial distribution of Chl-a concentrations in a small eutrophic lake and the patchy distribution of scum in Lake Como. ENVISAT MERIS time series collected from 2003 to 2011 enabled the identification of dates when cyanobacterial blooms affected water quality in three small meso-eutrophic lakes in the same region. On average, algal blooms occurred in the three lakes for about 5 days a year, typically in late summer and early autumn. A suite of hyperspectral sensors on air- and space-borne platforms was used to map Chl-a concentrations in the productive waters of the Mantua lakes, finding values in the range of 20 to 100 mgm-3. The present findings were obtained by applying state of the art of methods applied to remote sensing data. Further research will focus on improving the accuracy of cyanobacteria mapping and adapting the algorithms to the new-generation of satellite sensors.


The growth of Microcystis aeruginosa in a small, shallow eutrophic lake was studied during three consecutive seasons. The alga was shown to be continuously present in the plankton throughout the period. Exponential increase in the population was confined to a 5 to 8-week period, following the onset of thermal stratification. Populations appeared to originate near the bottom of the euphotic zone. The possession of an effective light-dependent buoyancy control mechanism enabled the alga to maintain station, though progressive deterioration of the photic conditions forced populations to rise and become dissipated within the epilimnion. Buoyancy increased after the cessation of growth; surface blooms often led to the physical removal of a majority of colonies to lee shores. Surviving colonies became generally less buoyant after the lake destratified in autumn.


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