scholarly journals Whole-Ecosystem Experiments Reveal Varying Responses of Phytoplankton Functional Groups to Epilimnetic Mixing in a Eutrophic Reservoir

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 222 ◽  
Author(s):  
Mary Lofton ◽  
Ryan McClure ◽  
Shengyang Chen ◽  
John Little ◽  
Cayelan Carey
Keyword(s):  
Community Composition ◽  
Green Algae ◽  
Phytoplankton Community ◽  
Water Reservoir ◽  
Ecosystem Dynamics ◽  
Bubble Plume ◽  
Community Responses ◽  
Drinking Water Reservoir ◽  
Biological Variables ◽  
Lakes And Reservoirs

Water column mixing can influence community composition of pelagic phytoplankton in lakes and reservoirs. Previous studies suggest that low mixing favors cyanobacteria, while increased mixing favors green algae and diatoms. However, this shift in community dominance is not consistently achieved when epilimnetic mixers are activated at the whole-ecosystem scale, possibly because phytoplankton community responses are mediated by mixing effects on other ecosystem processes. We conducted two epilimnetic mixing experiments in a small drinking water reservoir using a bubble-plume diffuser system. We measured physical, chemical, and biological variables before, during, and after mixing and compared the results to an unmixed reference reservoir. We observed significant increases in the biomass of cyanobacteria (from 0.8 ± 0.2 to 2.4 ± 1.1 μg L−1, p = 0.008), cryptophytes (from 0.7 ± 0.1 to 1.9 ± 0.6 μg L−1, p = 0.003), and green algae (from 3.8 to 4.4 μg L−1, p = 0.15) after our first mixing event, likely due to increased total phosphorus from entrainment of upstream sediments. After the second mixing event, phytoplankton biomass did not change but phytoplankton community composition shifted from taxa with filamentous morphology to smaller, rounder taxa. Our results suggest that whole-ecosystem dynamics and phytoplankton morphological traits should be considered when predicting phytoplankton community responses to epilimnetic mixing.

Forty years record of the metalimnetic oxygen minimum in Germany’s largest drinking water reservoir

2021 ◽  
Author(s):  
Michael Seewald ◽  
Chenxi Mi ◽  
Jan Donner ◽  
Karsten Rinke
Keyword(s):  
Drinking Water ◽  
Water Quality Management ◽  
Water Reservoir ◽  
Oxygen Depletion ◽  
Oxygen Deficit ◽  
Drinking Water Reservoir ◽  
Lakes And Reservoirs ◽  
Low Levels ◽  
Oxygen Minimum

<p>Dissolved oxygen is a central player in water quality management of lakes and reservoirs. Low levels or absence of oxygen poses a major problem, especially in drinking water reservoirs. Usually, the focus lies on the oxygen depletion in deep water. However, in many stably stratified water bodies, significant oxygen deficits have been documented in the metalimnion, even in lakes of low trophic state. This phenomenon is known as metalimnetic oxygen minimum (MOM) and the causes of MOM have been discussed controversially. The Rappbode Dam, Germany's largest drinking water reservoir, forms a MOM every year and long-term observations indicate that the oxygen deficit may have increased in recent years. Although the data cover a long period (40 years), they are very heterogeneous in terms of temporal and spatial resolution. Our study aims at systematically analysing the available data to characterize the interannual development of the MOM with respect to existing trends and to identify relevant environmental and management factors. The results confirm increasing surfacewater temperatures and unchanged deepwater temperatures in summer (Mai to October) as well as an increasingly prolonged summer stratification in the course of global warming. In contrast to the previous working hypothesis, increasing stratification duration is not correlated with the significantly increasing (p 0.009; τ -0.26) annual maximum intensity of the MOM.</p>

scholarly journals Community Compositions of Phytoplankton and Eukaryotes during the Mixing Periods of a Drinking Water Reservoir: Dynamics and Interactions

2020 ◽  
Vol 17 (4) ◽  
pp. 1128 ◽  
Author(s):  
Miaomiao Yan ◽  
Shengnan Chen ◽  
Tinglin Huang ◽  
Baoqin Li ◽  
Nan Li ◽  
...  
Keyword(s):  
Drinking Water ◽  
Phytoplankton Community ◽  
Morphological Characteristics ◽  
Water Reservoir ◽  
Shaanxi Province ◽  
Heihe River ◽  
Algal Density ◽  
Eukaryotic Community ◽  
Drinking Water Reservoir ◽  
Eukaryotic Microorganisms

In deep drinking water reservoir ecosystems, the dynamics and interactions of community compositions of phytoplankton and eukaryotes during the mixing periods are still unclear. Here, morphological characteristics combined with high-throughput DNA sequencing (HTS) were used to investigate the variations of phytoplankton and the eukaryotic community in a large canyon-shaped, stratified reservoir located at the Heihe River in Shaanxi Province for three months. The results showed that Bacillariophyta and Chlorophyta were the dominant taxa of the phytoplankton community, accounting for more than 97% of total phytoplankton abundance, which mainly consisted of Melosira sp., Cyclotella sp., and Chlorella sp., respectively. Illumina Miseq sequencing suggested that the biodiversity of eukaryotes increased over time and that species distribution was more even. Arthropoda (6.63% to 79.19%), Ochrophyta (5.60% to 35.16%), Ciliophora (1.81% to 10.93%) and Cryptomonadales (0.25% to 11.48%) were the keystone taxa in common, contributing over 50% of the total eukaryotic community. Cryptomycota as a unique fungus was observed to possess significant synchronization with algal density, reaching a maximum of 10.70% in December (when the algal density distinctly decreased) and suggesting that it might affect the growth of algae through parasitism. Co-occurrence network patterns revealed the complicated and diverse interactions between eukaryotes and phytoplankton, suggesting that eukaryotes respond to variations in dynamic structure of the phytoplankton community, although there might be antagonistic or mutualistic interactions between them. Redundancy analysis (RDA) results showed that environmental variables collectively explained a 96.7% variance of phytoplankton and 96.3% variance of eukaryotic microorganisms, indicating that the temporal variations of phytoplankton and eukaryotic microorganisms were significantly affected by environmental conditions. This study shows that potential interactions exist between phytoplankton and eukaryotic microorganism communities, andcould improve our understanding of the ecological roles of phytoplankton and eukaryotic microorganisms in changing aquatic ecosystems. However, long-term investigations are necessary in order to obtain comprehensive understandings of their complicated associations.

Phytoplankton community of the drinking water supply reservoir Borovitsa (South Bulgaria) with an emphasis on cyanotoxins and water quality

2010 ◽  
Vol 5 (2) ◽  
pp. 231-239 ◽  
Author(s):  
Ivanka Teneva ◽  
Rumen Mladenov ◽  
Detelina Belkinova ◽  
Ivanka Dimitrova-Dyulgerova ◽  
Balik Dzhambazov
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Physicochemical Parameters ◽  
Phytoplankton Community ◽  
Water Reservoir ◽  
Food Chains ◽  
Raw Water ◽  
Phytoplankton Diversity ◽  
Drinking Water Reservoir ◽  
Indirect Exposure

AbstractThe phytoplankton diversity, algal biomass, and selected physicochemical parameters were investigated in the drinking water reservoir (Borovitsa) located in the Kardzhali region, Bulgaria. Particular attention was given to Cyanoprokaryota and presence of cyanotoxins in the water samples. Twenty-nine species belonging to six divisions (Cyanoprokaryota, Chlorophyta, Zygnemophyta, Dinophyta, Euglenophyta and Bacillariophyta) were identified. The microscopic examination of the phytoplankton samples showed the dominance of Ankyra judayi, Oocystis lacustris (Chlorophyta) and Aphanizomenon flos-aquae (Cyanoprokaryota) in July 2006, and Microcystis pulverea, Synechococcus elongatus (Cyanoprokaryota), Radiococcus planktonicus (Chlorophyta) and Melosira varians (Bacillariophyta) in September 2006. A blooming event due to Aphanizomenon flos-aquae was observed in July 2006. The reservoir exhibits a tendency to shift from an oligotrophic environment to a state of mesotrophy. Presence of cyanotoxins such as anatoxin-a, microcystins and saxitoxins were analyzed by HPLC and ELISA methods. Our results demonstrated the presence of anatoxin-a and microcystins (0.09 µg/L) in the raw water samples from July 2006, and saxitoxins (2.5 µg/L) and microcystins (0.18 µg/L) in the raw water samples from September 2006. The study underlines that permanent monitoring programs of Cyanoprokaryota in the reservoirs used as sources of drinking water and toxicity assessments should be implemented. Indirect exposure and transfer of cyanotoxins through food chains must also be considered.

Investigating the effectiveness of bubble-plume destratification systems in a temperate, shallow, drinking water reservoir

2021 ◽  
Author(s):  
Jack Waterhouse ◽  
Thomas Kjeldsen ◽  
Lee Bryant
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Dissolved Oxygen ◽  
Water Reservoir ◽  
Medium Size ◽  
Bubble Plume ◽  
Water Reservoirs ◽  
Field Campaign ◽  
Drinking Water Reservoir ◽  
Oxygen Concentrations

<p>Thermal destratification of lakes and reservoirs is a primary control on dissolved-oxygen levels below the thermocline. In such waterbodies, internal biogeochemical processes are often controlled by a complex set of oxygen-controlled forcing mechanisms. Therefore, preventing stratification by artificial processes has long been an important tool in maintaining dissolved oxygen concentrations and corresponding water quality and ecosystem health in drinking water reservoirs. Blagdon Lake in Somerset, SW England is a medium-size (1.8km<sup>2</sup>), shallow depth (max: 13.1m) drinking water reservoir. An extensive 6-month field campaign was undertaken in the summer of 2019 at the reservoir, measuring depth profiles of dissolved oxygen, turbidity, conductivity, temperature and pH using an EXO3 multiparameter sonde and a CastAway® CTD. In addition, two thermistor chains were permanently installed measuring temperature and dissolved oxygen concentrations using Onset TidbiT v2 loggers (1m depth intervals) through the water column at 30-minute temporal resolution and a miniDOT oxygen logger at the sediment-water interface respectively. These thermistor chains collected data from summer 2019 – autumn 2020. The data from this field campaign were analysed to investigate the effectiveness of the installed bubble-plume destratification system present at Blagdon Lake, SW England. Similar systems are used in 66% of UK reservoirs employing artificial mixing infrastructure, though very little has been published evaluating their effectiveness in such temperate, shallow, drinking water reservoirs. Initial analysis of the results indicates that the bubble-plume system, nor wind shear is effectively preventing spring/summer destratification for long periods, and that neither are the main factor controlling thermal stratification in Blagdon Lake. The data provides a unique opportunity to directly assess the impact of bubble-plume aerators and their effectiveness at thermal destratification to control dissolved oxygen and water quality in temperate, shallow water bodies.</p>

Inspecting the Uninspectable: a 40-year-old force main beneath a drinking water reservoir. Failure is not an option

2017 ◽  
Vol 2017 (6) ◽  
pp. 4586-4604
Author(s):  
Ari Elden ◽  
Gary Skipper ◽  
Don Gordon ◽  
Ernesto Fernandez ◽  
Chris Garrett
Keyword(s):  
Drinking Water ◽  
Water Reservoir ◽  
Drinking Water Reservoir

Identification of MIB producers and odor risk assessment using routine data: A case study of an estuary drinking water reservoir

2021 ◽  
Vol 192 ◽  
pp. 116848
Author(s):  
Ming Su ◽  
Yiping Zhu ◽  
Zeyu Jia ◽  
Tingting Liu ◽  
Jianwei Yu ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Drinking Water ◽  
Water Reservoir ◽  
Routine Data ◽  
Drinking Water Reservoir

scholarly journals Effect of hydrogen peroxide on natural phytoplankton and bacterioplankton in a drinking water reservoir: Mesocosm-scale study

2021 ◽  
pp. 117069
Author(s):  
Allan A. Santos ◽  
Dayvson O. Guedes ◽  
Mário U.G. Barros ◽  
Samylla Oliveira ◽  
Ana B.F. Pacheco ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Drinking Water ◽  
Water Reservoir ◽  
Drinking Water Reservoir ◽  
Natural Phytoplankton

scholarly journals Are Bacterio- and Phytoplankton Community Compositions Related in Lakes Differing in Their Cyanobacteria Contribution and Physico-Chemical Properties?

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 855
Author(s):  
Mikołaj Kokociński ◽  
Dariusz Dziga ◽  
Adam Antosiak ◽  
Janne Soininen
Keyword(s):  
Environmental Factors ◽  
Community Composition ◽  
Phytoplankton Community ◽  
Heterotrophic Bacteria ◽  
Bacterial Community Composition ◽  
Physical Factors ◽  
Research Attention ◽  
Phytoplankton Community Composition ◽  
The Impact ◽  
Bacteria Communities

Bacterioplankton community composition has become the center of research attention in recent years. Bacteria associated with toxic cyanobacteria blooms have attracted considerable interest. However, little is known about the environmental factors driving the bacteria community, including the impact of invasive cyanobacteria. Therefore, our aim has been to determine the relationships between heterotrophic bacteria and phytoplankton community composition across 24 Polish lakes with different contributions of cyanobacteria including the invasive species Raphidiopsis raciborskii. This analysis revealed that cyanobacteria were present in 16 lakes, while R. raciborskii occurred in 14 lakes. Our results show that bacteria communities differed between lakes dominated by cyanobacteria and lakes with minor contributions of cyanobacteria but did not differ between lakes with R. raciborskii and other lakes. Physical factors, including water and Secchi depth, were the major drivers of bacteria and phytoplankton community composition. However, in lakes dominated by cyanobacteria, bacterial community composition was also influenced by biotic factors such as the amount of R. raciborskii, chlorophyll-a and total phytoplankton biomass. Thus, our study provides novel evidence on the influence of environmental factors and R. raciborskii on lake bacteria communities.

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