scholarly journals Periphytic diatoms in the presence of a cyanobacterial bloom: A case study of the Vrutci Reservoir in Serbia

2019 ◽  
Vol 71 (2) ◽  
pp. 215-223 ◽  
Author(s):  
Ivana Trbojevic ◽  
Dragana Predojevic ◽  
Gordana Subakov-Simic ◽  
Jelena Krizmanic

Despite their unique ecology and implications for ecological assessment, diatoms in lentic ecosystems are still insufficiently studied in both scientific research and operational monitoring. In particular, the ecology of periphytic diatoms relative to the global expansion of cyanobacterial blooms in lakes has not been described at all. This study aims to describe the diversity and dynamics of a periphytic diatom community in the Vrutci Reservoir during Planktothrix rubescens bloom, and to evaluate the adequacy of standard diatom index implementation in lentic ecosystems relative to the diatom index adapted for lakes ? the Trophic Diatom Index for Lakes (TDIL). The study was conducted in the Vrutci Reservoir in western Serbia. Periphyton was developed on an artificial glass substrate during the summer of 2015, following a depth gradient of a stratified water column. Diatom diversity and abundance, as well as diatom indices were estimated. Discounting the cyanobacterial bloom, 79 taxa of diatoms were recorded and among them the species Aneumastus stroesei as the first representative of the entire genus Aneumastus ever to be detected in Serbia. Diatom distribution along the depth gradient was clearly associated with shifts in environmental conditions. TDIL showed an advantage over standard diatom indices in terms of stability during experimental period and uniformity along the depth gradient, indicating the necessity for further testing of this index performance in lakes, and consequently local water-quality legislation update.

2019 ◽  
Author(s):  
Wayne Hamilton ◽  
◽  
Stephanie S. Wong ◽  
Wynne Casteel ◽  
Ashley McGill ◽  
...  

Author(s):  
Yilin Qian ◽  
Kunihiro Okano ◽  
Miwa Kodato ◽  
Michiko Arai ◽  
Takeru Yanagiya ◽  
...  

Abstract Toxic cyanobacterial blooms frequently develop in eutrophic freshwater bodies worldwide. Microcystis species produce microcystins (MCs) as a cyanotoxin. Certain bacteria that harbor the mlr gene cluster, especially mlrA, are capable of degrading MCs. However, MCs-degrading bacteria may possess or lack mlr genes (mlr+ and mlr− genotypes, respectively). In this study we investigated the genotype that predominantly contributes to biodegradation and cyanobacterial predator community structure with change in total MCs concentration in an aquatic environment. The two genotypes co-existed but mlr+ predominated, as indicated by the negative correlation between mlrA gene copy abundance and total MCs concentration. At the highest MCs concentrations, predation pressure by Phyllopoda, Copepoda, and Monogononta (rotifers) was reduced; thus, MCs may be toxic to cyanobacterial predators. The results suggest cooperation between MCs-degrading bacteria and predators may reduce Microcystis abundance and MCs concentration.


2008 ◽  
Vol 51 (4) ◽  
pp. 633-641 ◽  
Author(s):  
Naithirithi Tiruvenkatachary Chellappa ◽  
Sarah Laxhmi Chellappa ◽  
Sathyabama Chellappa

The aim of this work was to study the eutrophication in the tropical freshwater ecosystems and the consequent cyanobacterial bloom formation and economical damage to fisheries and harmful effects to public health. Mass fish mortality due to toxin producing cyanobacterial blooms was registered during December 2003 in Marechal Dutra Reservoir, Acari/RN, Northeast Brazil. Phytoplankton and fish samplings were carried out on alternate days during the episode of fish mortality and monthly during January to June 2004. The cyanobacterial toxin was identified and quantified from the seston samples and liver of the dead fishes using the standard HPLC method. The results indicated that the toxic blooms of Cylindrospermopsis raciborskii and Microcystis aeruginosa were persistent for two weeks and represented 90% of the phytoplankton species assemblages. The lethally affected fishes were Oreochromis niloticus, Plagioscion squamosissimus, Cichla monoculus, Prochilodus brevis, Hoplias malabaricus and Leporinus friderici. The microcystin levels varied from 0.07 to 8.73µg L-1 the seston samples and from 0.01 to 2.59µg g-1in the liver samples of the fishes during the bloom period.


2001 ◽  
Vol 1 (2) ◽  
pp. 237-246 ◽  
Author(s):  
M. Tarczyńska ◽  
Z. Romanowska-Duda ◽  
T. Jurczak ◽  
M. Zalewski

Eutrophication of reservoirs used for drinking water supplies is a very common problem, particularly in lowland reservoirs. Long water retention time (60-120 days) favours cyanobacterial bloom occurrence in Sulejów Reservoir, Poland. The localisation of the water intake in a bay exposed to north-east winds favoured the Microcystis bloom accumulation, which formed a 0.5 m thick dense scum for the first time in September 1999. Cyanobacterial hepatotoxins can pose a potential health problem because the presence of about 0.8 μg/l microcystins was detected in drinking water during three series of analysis. An investigation of the efficiency of each stage of water treatment processes in the elimination of microcystins showed that pre-chlorination, coagulation, and rapid sand filtration were ineffective in removing microcystins from water. Significant elimination was observed after ozonation and chlorination. The concentration of microcystins in bloom material was between 12 to 860 μg/g dry weight of phytoplankton biomass. Management strategies for reservoirs should consider the important role of ecohydrological processes, which are often very easy to regulate, and which can be useful for bio-manipulation of the water ecosystem.


2019 ◽  
Vol 76 (11) ◽  
pp. 2102-2109 ◽  
Author(s):  
Blake R. Stuparyk ◽  
Mark Graham ◽  
Jenna Cook ◽  
Mitchell A. Johnsen ◽  
Karen K. Christensen-Dalsgaard ◽  
...  

Cyanobacterial blooms in lakes of low nutrient status are recent ecological surprises. Culling of planktivorous fish may help suppress phytoplankton blooms via a trophic cascade effect. To test this hypothesis, we conducted a 90-day experiment adjacent to a shallow oligomesotrophic lake increasingly beset by midsummer cyanobacterial blooms in the presence of high abundances of minnows and sparse herbivorous zooplankton. The single-factor (± three spottail shiners, Notropis hudsonius) experimental design was replicated 10 times for a total of twenty 1200 L capacity mesocosms. Contrary to the trophic cascade hypothesis, minnow removal decreased the abundance of bosminids capable of grazing cyanobacteria. Nevertheless, removal of the minnows significantly both suppressed phytoplankton biomass and offset the development of cyanobacteria, such as Gloeotrichia echinulata. Lower concentrations of phosphorus and nitrogen in the fishless relative to stocked mesocosms best explained these differences in the phytoplankton community. Our findings highlight how fisheries management practices that enhance minnow populations in lakes of low productivity may inadvertently contribute to cyanobacterial blooms through increased nutrient cycling.


Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2265
Author(s):  
Peng Gu ◽  
Qi Li ◽  
Hao Zhang ◽  
Xin Luo ◽  
Weizhen Zhang ◽  
...  

Cyanobacterial blooms caused by eutrophication in Lake Taihu have led to ecological threats to freshwater ecosystems. A pilot scale experiment was implemented to investigate the relationship between cyanobacteria and other aquatic plants and animals in simulated eutrophic ecosystems under different phosphorus (P) regimes. The results of this study showed that cyanobacteria had two characteristics favorable for bloom formation in eutrophic ecosystems. One is the nutrient absorption. The presence of alkaline phosphatase was beneficial for algal cells in nutrition absorption under low P concentration. Cyanobacteria exhibited a stronger ability to absorb and store P compared to Vallisneria natans, which contributed to the fast growth of algal cells between 0.2 and 0.5 mg·L−1 of P (p < 0.05). However, P loads affected only the maximum biomass, but not the growth phases. The growth cycle of cyanobacteria remained unchanged and was not related to P concentration. P cycling indicated that 43.05–69.90% of the total P existed in the form of sediment, and P content of cyanobacteria showed the highest increase among the organisms. The other is the release of microcystin. Toxic microcystin-LR was released into the water, causing indirectly the growth inhibition of Carassius auratus and Bellamya quadrata and the reduction of microbial diversity. These findings are of importance in exploring the mechanism of cyanobacterial bloom formation and the nutrient management of eutrophic lakes.


2018 ◽  
Vol 10 (12) ◽  
pp. 4386 ◽  
Author(s):  
Ruben Weesie ◽  
Angela Kronenburg García

Improving water supply for irrigable farming and livestock purposes in communities in Africa is an increasingly popular approach for community-based adaptation interventions. A widespread intervention is the construction of agro-pastoral dams and irrigation schemes in traditionally pastoral communities that face a drying climate. Taking the Maji Moto Maasai community in southern Kenya as a case study, this article demonstrates that water access inequality can lead to a breakdown of pre-existing social capital and former pastoral cooperative structures within a community. When such interventions trigger new water uses, such as farming in former pastoral landscapes, there are no traditional customary institutional structures in place to manage the new water resource. The resulting easily corruptible local water management institutions are a main consolidator of water access inequalities for intervention beneficiaries, where socio-economic standing often determines benefits from interventions. Ultimately, technological adaptation interventions such as agro-pastoral dams may result in tensions and a high fragmentation of adaptive capacity within target communities.


2013 ◽  
Vol 448-453 ◽  
pp. 43-47 ◽  
Author(s):  
Xin Tang ◽  
De Suo Cai ◽  
Wen Ting Yao

In order to evaluate the water quality of Longjiang river comprehensively, diatoms of 15 sampling sites are collected to establish the Grey Relational Model based on three diatom indexesIPS, IBD and IDG. From the Cluster analysis of sampling sites and the box plot of diatom index, IBD is the best, then the IPS, the diatom index weights on water quality assessment are 0.637 for IBD, 0.2583 for IPS, 0.1074 for IDG respectively. Finally, by comparing the water quality standard level based on Grey Relational Model, it can be known that the water quality of most sampling sites is fine except that site No.1 and No.3 belong to III water quality standard. The result shows that it is more comprehensive and reasonable to use the Grey Relational Model based on diatom index rather than individual diatom index to assess water quality.


2014 ◽  
Vol 931-932 ◽  
pp. 619-623
Author(s):  
Sun Olapiriyakul

The rapid growth of industry has resulted in increased severity of water scarcity in the Eastern region of Thailand over the past decade. The assessment of water use by industrial manufacturing processes located in areas experiencing water stress is necessary to ensure a sustainable water resources management. The objective of this study is to demonstrate the use of life cycle assessment as a tool for assessing water use in an industrial manufacturing process. A case study of S-PVC resin manufacturing process located in Map Ta Phut Industrial Estate, Rayong province, Thailand, is presented. The studying results indicate that the amount of water used to produce 1 Kg of S-PVC resin is 14.72 liters, of which 6.22 liters are withdrawn from local water resources. Additionally, the direct and indirect water use along the production supply chain is accounted for in a streamlined life cycle assessment.


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