Planktonic production and respiration in a subtropical lake dominated by Cyanobacteria

Tonetta, Denise; Laudares-Silva, Roselane; Petrucio, Maurício Mello

doi:10.1590/1519-6984.17513

Cited by 7 publications

(4 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our results also confirm previous findings using bottles incubation, where the highest primary production was recorded at subsurface, decreasing with depth (Tonetta et al, 2015b). Furthermore, the authors presented that the highest respiration rates occurred at 1.0 m depth, and did not increase with depth, showing a more homogeneous condition to the pelagic 6.…”

Section: Vertical and Horizontal Variability In Metabolic Ratessupporting

confidence: 92%

Physical conditions driving the spatial and temporal variability in aquatic metabolism of a subtropical coastal lake

et al. 2016

View full text Add to dashboard Cite

a b s t r a c tWe investigated the importance of meteorological and lake physical conditions for temporal, horizontal and vertical differences in the concentration of dissolved oxygen (DO) and water temperature, and the derived daily estimates of gross primary production (GPP), ecosystem respiration (R) and net ecosystem production (NEP). Our study was conducted in a subtropical and polymictic lake in Southern Brazil, during a spring-summer transition. Metabolic rates were determined from two sites using the open water oxygen technique. At the central deep site, oxygen sondes were deployed at three depths to assess patterns in vertical variability. During 10 days, an additional DO and temperature sonde was placed near the shoreline allowing us to compare metabolic differences in the surface layers between the central pelagic and littoral site. While GPP was similar, R was significantly higher at the shallower littoral site, causing NEP to be lower, although NEP was still positive. The littoral site had less diel changes in DO and higher daily variability in all metabolic rates. Variability in GPP and R at the littoral site was related to temperature, wind speed and rainfall suggesting that short-term variability in metabolic rates in shallow areas are sensitive to resuspension of sediments caused by a less stable water column. A clear vertical gradient was furthermore found for the metabolic rates at the central deep part of the lake, related to the light extinction, with highest GPP around 0.3 m and decreasing with depth, while respiration showed the inverse pattern. Below subsurface, respiration prevailed at 5.0 m depth and was uncoupled to primary production. Under conditions with high light and temperature, and low wind speeds, the mixing depth became shallower, in turn increasing the water column stability at the deep pelagic site, which resulted in higher mean light available and higher GPP in the water column. Our results confirm that deployment of sensors in different sites and depths allows for spatially, as well as temporally more representative estimates of lake metabolism.

show abstract

Section: Vertical and Horizontal Variability In Metabolic Ratessupporting

confidence: 92%

Physical conditions driving the spatial and temporal variability in aquatic metabolism of a subtropical coastal lake

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Peri Lake is predominantly CO 2 supersaturated (Tonetta et al 2015;Fontes et al 2015;and this study) with at least one period of influx (summer). The pCO 2 concentrations and CO 2 flux can also be regulated by meteorological factors such as turbulence in the water column caused by advection or wind shear (MacIntyre et al 2010;Read et al 2012).…”

Section: Discussionmentioning

confidence: 82%

Linking summer conditions to CO2 undersaturation and CO2 influx in a subtropical coastal lake

2015

View full text Add to dashboard Cite

In this study, we tested the hypothesis that pCO 2 and air-water CO 2 fluxes in the surface waters of a subtropical lake vary on two time scales (diel and seasonally) and that CO 2 concentrations would decrease during the day and in summer. We estimated the variability of pCO 2 and the air-water CO 2 flux from pH-alkalinity in four 48-h periods that were representative of each subtropical season. There was high variability in pCO 2 and the air-water gas flux over 48 h, but there was no clear pattern between day and night. CO 2 concentrations showed a strong positive correlation with heterotrophic bacterial biomass and a negative correlation with dissolved organic carbon concentrations and water temperature. The lake was predominantly diel and seasonally CO 2 supersaturated; the highest CO 2 efflux was observed in the spring and a CO 2 influx was observed in summer. Our hypothesis was confirmed; pCO 2 was lowest in summer and during the daytime in spring and summer due to physical and biological conditions that favoured photosynthetic activities. These findings suggest that temporal shifts in the microbial community and meteorological variables, which are indirectly related to temperature, may be important drivers of CO 2 concentrations in Peri Lake. In conclusion, pCO 2 and the air-water CO 2 flux vary temporally (diel and seasonally) in the littoral zone of this subtropical coastal lake, with shifts between CO 2 influx and efflux throughout the sampling periods.

show abstract

“…Zhang et al [24] observed that maximum growth occurred at 0.3 m of the water column for diatoms, chlorophytes, and cyanobacteria which decreased as irradiance increased in Lake Taihu, China. Similarly, in Peri Lake, Brazil, a higher primary production rate of the toxic cyanobacteria species Cylindrospermopsis was found at the surface and decreased as a function of water column depth [25]. In addition, the thermal gradient and mixing which causes stratification in the water column is also reported to influence the seasonal composition of phytoplankton by controlling the nutrient distribution in the water column [21].…”

Section: Introductionmentioning

confidence: 93%

“…Cyanobacteria species may gain dominance by using gas vesicles, which enable them to regulate their buoyancy, for vertical movement in the water column to track for light, nutrients, and favorable water temperature [24]. These gas vesicles have notable similarities in molecular structure amongst cyanobacterial genera, but they differ in shape, yield, and critical pressures, with Microcystis having a more stable gas vesicle compared to others [25]. It is reported that the optimal habitat for phytoplankton growth is at a depth of 3 m to 5 m within the water column [20].…”

Section: Introductionmentioning

confidence: 99%

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

Sirunda

Oberholster

Wolfaardt

et al. 2021

Water

View full text Add to dashboard Cite

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-a, 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. Microcystis dominated the vertical and temporal dynamics, followed by Dolichospermum. 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.

show abstract

Planktonic production and respiration in a subtropical lake dominated by Cyanobacteria

Cited by 7 publications

References 36 publications

Physical conditions driving the spatial and temporal variability in aquatic metabolism of a subtropical coastal lake

Physical conditions driving the spatial and temporal variability in aquatic metabolism of a subtropical coastal lake

Linking summer conditions to CO2 undersaturation and CO2 influx in a subtropical coastal lake

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

Contact Info

Product

Resources

About