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Visser, Petra M.; Passarge, J.; Mur, Luuc R.

doi:10.1023/a:1003001713560

Cited by 147 publications

(58 citation statements)

References 27 publications

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“…Meanwhile, the ADCP recorded near-surface vertical movement of colonies was bi-direction. During post-typhoon period, cyanobacterial colonies unifromly ascended to aggregate at water surface ( Figure 2B ) at speed about 0.5 cm/s near surface and 0.3 cm/s near bottom (Wu et al, 2013), which was much higher than previous reported about 10 -4 m/s (Reynolds et al, 1987) and similar with Visser et al (1997) documented as 0.7 cm/s for the colony diameter ∼400 μm. This higher vertical speed mainly caused by the buoyancy of large colones of Microcystis (Oliver, 1994; Wallace and Hamilton, 1999; Wu and Kong, 2009).…”

Section: Discussionsupporting

confidence: 75%

“…This accomplished by carbohydrates synthesized during the day increase the cell density to cause cells sink. Conversely carbohydrates are consumed at night, decreasing the cell density and providing positive buoyance to form blooms in the next morning (Visser et al, 1997). If the wind speed were greater than 3 m/s, wind-induced mixing would result the surface visible bloom vanishment (George and Edwards, 1976; Webster and Hutchinson, 1994; Brookes et al, 2003; Wu et al, 2013).…”

Section: Discussionmentioning

confidence: 99%

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Spatiotemporal Changes of Cyanobacterial Bloom in Large Shallow Eutrophic Lake Taihu, China

Qin

Yang

et al. 2018

Front. Microbiol.

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Lake Taihu is a large shallow eutrophic lake with frequent recurrence of cyanobacterial bloom which has high variable distribution in space and time. Based on the field observations and remote sensing monitoring of cyanobacterial bloom occurrence, in conjunction with laboratory controlled experiments of mixing effects on large colony formation and colonies upward moving velocity measurements, it is found that the small or moderate wind-induced disturbance would increase the colonies size and enable it more easily to overcome the mixing and float to water surface rapidly during post-disturbance. The proposed mechanism of wind induced mixing on cyanobacterial colony enlargement is associated with the presence of the extracellular polysaccharide (EPS) which increased the size and buoyancy of cyanobacteria colonies and promote the colonies aggregate at the water surface to form bloom. Both the vertical movement and horizontal migration of cyanobacterial colonies were controlled by the wind induced hydrodynamics. Because of the high variation of wind and current coupling with the large cyanobacterial colony formation make the bloom occurrence as highly mutable in space and time. This physical factor determining cyanobacterial bloom formation in the large shallow lake differ from the previously documented light-mediated bloom formation dynamics.

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Section: Discussionsupporting

confidence: 75%

Section: Discussionmentioning

confidence: 99%

Spatiotemporal Changes of Cyanobacterial Bloom in Large Shallow Eutrophic Lake Taihu, China

Qin

Yang

et al. 2018

Front. Microbiol.

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“…This feature is interesting because it corresponds with the size range where colonies can enhance vertical migration capacity. Visser et al (1997) modeled the impact of Microcystis colony size on vertical migration, and determined that maximal migration depth ranges (i.e., the range of migration) were achieved at sizes around 200 µm. Size and toxin production have also been linked, shown to be enhanced with increasing colony size (Harke et al, 2016).…”

Section: Biomass and Plankton Distributionsmentioning

confidence: 99%

“…We visually observed Microcystis colonies in surface waters at stations in the MB, and noted accumulation at the surface over short periods of time (an hour or less) when winds were low at several stations, although we did not observe any thick scums. The arrangement of layered aggregated Microcystis cells into colonies changes their overall optical properties through package effects on absorption (Kirk, 1994) and enhancing scattering from increased cellular vacuole content (Matthews and Bernard, 2013) if the colonies are surfacing through increased buoyancy (Visser et al, 1997). Nevertheless, the similarities of the Junge slope for the MB and CB indicate that globular and strand-like cyanobacteria colonies have similar size distribution characteristics for particles <200 µm, despite morphological differences.…”

Section: Biomass and Plankton Distributionsmentioning

confidence: 99%

Bio-optical Properties of Cyanobacteria Blooms in Western Lake Erie

et al. 2017

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There is a growing use of remote sensing observations for detecting and quantifying freshwater cyanobacteria populations, yet the inherent optical properties of these communities in natural settings, fundamental to bio-optical algorithms, are not well known. Toward bridging this knowledge gap, we measured a full complement of optical properties in western Lake Erie during cyanobacteria blooms in the summers of 2013 and 2014. Our measurements focus attention on the optical uniqueness of cyanobacteria blooms, which have consequences for remote sensing and bio-optical modeling. We found the cyanobacteria blooms in the western basin during our field work were dominated by Microcystis, while the waters in the adjacent central basin were dominated by Planktothrix. Chlorophyll concentrations ranged from 1 to over 135 µg/L across the study area with the highest concentrations associated with Microcystis in the western basin. We observed large, amorphous colonial Microcystis structures in the bloom area characterized by high phytoplankton absorption and high scattering coefficients with a mean particle backscatter ratio at 443 nm > 0.03, which is higher than other plankton types and more comparable to suspended inorganic sediments. While our samples contained mixtures of both, our analysis suggests high contributions to the measured scatter and backscatter coefficients from cyanobacteria. Our measurements provide new insights into the optical properties of cyanobacteria blooms, and indicate that current semi-analytic models are likely to have problems resolving a closed solution in these types of waters as many of our observations are beyond the range of existing model components. We believe that different algorithm or model approaches are needed for these conditions, specifically for phytoplankton absorption and particle backscatter components. From a remote sensing perspective, this presents a challenge not only in terms of a need for new algorithms, but also for determining when to apply the best Moore et al. Lake Erie IOPs algorithm for a given situation. These results are new in the sense that they represent a complete description of the optical properties of freshwater cyanobacteria blooms, and are likely to be representative of bloom conditions for other systems containing Microcystis cells and colonies.

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“…It is possible now to study the impact of circulation on algae migration by superimposition of the flow field given by Fig. 5 (for example) and a maximum vertical velocity of the algae of v a = ± 3 mm/s (see Kromkamp and Walsby, 1990;Visser et al, 1997). The results of this superimposition are shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Circulation induced by diffused aeration in a shallow lake

Toné

Pacheco

Neto

2017

WSA

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Field surveys were carried out to investigate the surface jet flows and the resulting circulation patterns generated by diffused aeration in a shallow lake. In conrast to previous studies, the experimental conditions included point-source bubble plumes with very high air flow rates (100-400 L/min) relative to the shallow water depth (1.5 m). The results indicate that the surface jet velocity can be described by linear profiles. The decay of this velocity with distance displayed a similar behaviour to that reported in the literature, but the surface jet spread much faster under the present conditions. Combining our results with published data allowed for the generation of dimensionless correlations for the velocity and depth of the surface jet. A good agreement between the total circulation flow rates predicted by using the proposed correlations and integral modelling was also obtained. Lastly, a simple returning flow model was proposed to describe the circulation flow patterns induced by the bubble plumes. The results were also applied to assess the impact of circulation on vertical algae migration, which is important for water quality management.

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Untitled

Cited by 147 publications

References 27 publications

Spatiotemporal Changes of Cyanobacterial Bloom in Large Shallow Eutrophic Lake Taihu, China

Spatiotemporal Changes of Cyanobacterial Bloom in Large Shallow Eutrophic Lake Taihu, China

Bio-optical Properties of Cyanobacteria Blooms in Western Lake Erie

Circulation induced by diffused aeration in a shallow lake

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