scholarly journals Harmful phytoplankton blooms and fish mortality in a eutrophicated reservoir of northeast Brazil

2008 ◽  
Vol 51 (4) ◽  
pp. 633-641 ◽  
Author(s):  
Naithirithi Tiruvenkatachary Chellappa ◽  
Sarah Laxhmi Chellappa ◽  
Sathyabama Chellappa
Keyword(s):  
Cyanobacterial Bloom ◽  
Hplc Method ◽  
Freshwater Ecosystems ◽  
Cyanobacterial Blooms ◽  
Fish Mortality ◽  
Cylindrospermopsis Raciborskii ◽  
Northeast Brazil ◽  
Cyanobacterial Toxin ◽  
Bloom Formation ◽  
Harmful Effects

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.

scholarly journals Effects of Cyanobacteria on Phosphorus Cycling and Other Aquatic Organisms in Simulated Eutrophic Ecosystems

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2265
Author(s):  
Peng Gu ◽  
Qi Li ◽  
Hao Zhang ◽  
Xin Luo ◽  
Weizhen Zhang ◽  
...  
Keyword(s):  
Nutrient Management ◽  
Lake Taihu ◽  
Cyanobacterial Bloom ◽  
Aquatic Organisms ◽  
Pilot Scale ◽  
Freshwater Ecosystems ◽  
Cyanobacterial Blooms ◽  
Eutrophic Lakes ◽  
P Concentration ◽  
Bloom Formation

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.

Antioxidant parameters in fish white muscle as biomarkers of exposure to a cyanobacterial bloom

Biologia ◽  
2015 ◽  
Vol 70 (6) ◽  
Author(s):  
Branka R. Gavrilović ◽  
Marko D. Prokić ◽  
Jelena P. Gavrić ◽  
Svetlana G. Despotović ◽  
Tijana B. Radovanović ◽  
...  
Keyword(s):  
White Muscle ◽  
Cyanobacterial Bloom ◽  
Perca Fluviatilis ◽  
Rutilus Rutilus ◽  
Fish Muscle ◽  
Freshwater Ecosystems ◽  
Cyanobacterial Blooms ◽  
Sod Activity ◽  
Sh Group ◽  
Antioxidant Parameters

AbstractThis study examines the responses of antioxidant parameters in the white muscle of four freshwater fish species: Rutilus rutilus (roach), Blicca bjoerkna (white bream), Carassius gibelio (Prussian carp) and Perca fluviatilis (European perch) after exposure to a bloom of Aphanizomenon flos-aquae (Cyanobacteria) in the Gruža Reservoir in Serbia. The set of analyzed biomarkers included the activities of antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and biotransformation phase II enzyme glutathione-S-transferase (GST), and the concentrations of total glutathione (GSH) and sulfhydryl (-SH) groups that were measured before and during the bloom. Our results show that SOD activity in C. gibelio and P. fluviatilis, GSH-Px and GST activities in all four fish, GR activity in R. rutilus and C. gibelio and the -SH group concentration in P. fluviatilis markedly decreased during the bloom. The activity of CAT in all four fish and the concentration of GSH in B. bjoerkna and P. fluviatilis significantly increased. The observed changes in nonspecific antioxidant biomarkers in fish muscle (especially CAT, GSH-Px and GST activities) suggest that these parameters could be useful tools in environmental monitoring programs of the freshwater ecosystems where cyanobacterial blooms occur.

scholarly journals Characterization of the Gene Cluster Responsible for Cylindrospermopsin Biosynthesis

2007 ◽  
Vol 74 (3) ◽  
pp. 716-722 ◽  
Author(s):  
Troco Kaan Mihali ◽  
Ralf Kellmann ◽  
Julia Muenchhoff ◽  
Kevin D. Barrow ◽  
Brett A. Neilan
Keyword(s):  
Gene Cluster ◽  
Global Scale ◽  
Open Reading Frames ◽  
Cyanobacterial Blooms ◽  
Cylindrospermopsis Raciborskii ◽  
Economic Losses ◽  
Cyanobacterial Toxin ◽  
Significant Public Health ◽  
Scale Characterization

ABSTRACT Toxic cyanobacterial blooms cause economic losses and pose significant public health threats on a global scale. Characterization of the gene cluster for the biosynthesis of the cyanobacterial toxin cylindrospermopsin (cyr) in Cylindrospermopsis raciborskii AWT205 is described, and the complete biosynthetic pathway is proposed. The cyr gene cluster spans 43 kb and is comprised of 15 open reading frames containing genes required for the biosynthesis, regulation, and export of the toxin. Biosynthesis is initiated via an amidinotransfer onto glycine followed by five polyketide extensions and subsequent reductions, and rings are formed via Michael additions in a stepwise manner. The uracil ring is formed by a novel pyrimidine biosynthesis mechanism and tailoring reactions, including sulfation and hydroxylation that complete biosynthesis. These findings enable the design of toxic strain-specific probes and allow the future study of the regulation and biological role of cylindrospermopsin.

Occurrence and possible causes of a severe cyanobacterial bloom in Lake Cargelligo, New South Wales

1994 ◽  
Vol 45 (5) ◽  
pp. 737 ◽  
Author(s):  
L Bowling
Keyword(s):  
New South ◽  
New South Wales ◽  
Cyanobacterial Bloom ◽  
Cyanobacterial Blooms ◽  
Toxicity Tests ◽  
Cylindrospermopsis Raciborskii ◽  
Nutrient Concentrations ◽  
Cell Numbers ◽  
South Wales ◽  
Physico Chemical

Although smaller cyanobacterial blooms had occurred in Lake Cargelligo in previous summers, a severe bloom of Anabaena circinalis occurred in the lake in November 1990. Cell numbers exceeded 100 000 cells m L -1 , and toxicity tests revealed the bloom to be highly hepatotoxic. This resulted in the first known closure of a town water supply due to cyanobacteria in New South Wales. Blooms of Microcystis aeruginosa, Aphanizomenon issatschenkoi, Oscillatoria rnougeotii and Cylindrospermopsis raciborskii also occurred in the lake at similar very high cell numbers during the summer and autumn of 1990-91. All five species persisted until May 1991, although there was no detectable toxicity from January onwards. Severe flooding in the Lachlan River valley upstream of Lake Cargelligo during the winter of 1990 led to nutrient enrlched inflows to the lake. These elevated nutrient concentrations would have been a major factor contributing to the bloom. However, other physico-chemical factors were also suitable for cyanobacterial growth.

scholarly journals Cyanobacterial blooms in freshwaters bodies in a semiarid region, northeastern Brazil: A review

2017 ◽  
Vol 77 (2) ◽  
Author(s):  
Ariadne do Nascimento Moura ◽  
Nisia K. C. Aragão-Tavares ◽  
Cihelio A. Amorim
Keyword(s):  
Dominant Species ◽  
Northeastern Brazil ◽  
Cyanobacterial Blooms ◽  
Cylindrospermopsis Raciborskii ◽  
Semiarid Region ◽  
Northeast Brazil ◽  
Freshwater Bodies ◽  
Toxic Blooms ◽  
Harmful Cyanobacterial Blooms ◽  
Density And Biomass

Harmful cyanobacterial blooms have caused several problems in freshwater environments due to their prolific growth and the harmful cyanotoxins produced by some species. The occurrence of these organisms has increased in recent decades due to climate change and eutrophication, although most studies are from temperate regions in the Northern hemisphere. This review presents data about cyanobacteria occurrence, dominance, and toxicity events in freshwater bodies in a semiarid region of Northeast Brazil, in the tropical Southern hemisphere. We performed a literature survey of cyanobacteria publications from 1930 to 2016. We made a list of all the dominant species registered in each state, noted their distribution and occurrence of dominance events involving one or more species, and the registered records of toxic blooms, including information about the toxins involved and the range of values. We selected 102 publications that described cyanobacteria occurrence from states in Northeast Brazil; these publications included relevant contributions regarding cyanobacteria distribution, richness, density, and biomass. Forty-nine dominant species were recorded, with the most representation found in the state of Pernambuco (30 spp.). The genera with the highest occurrences were Microcystis, Cylindrospermopsis, Planktothrix, Dolichospermum (=Anabaena), and Geitlerinema, especially the species Cylindrospermopsis raciborskii, Microcystis aeruginosa, and Planktothrix agardhii. Episodes of toxic blooms were observed in four states. Microcystins, cylindrospermopsin, saxitoxins, and anatoxin-a(S) were found to be associated with these blooms. In Northeast Brazil, harmful cyanobacterial blooms are common in urban and public reservoirs. However, in recent years, cyanobacterial blooms in this region have been more intense and perennial, with high biomass occurring throughout the year.

scholarly journals A Review of the Effect of Trace Metals on Freshwater Cyanobacterial Growth and Toxin Production

Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 643 ◽  
Author(s):  
Jordan A. Facey ◽  
Simon C. Apte ◽  
Simon M. Mitrovic
Keyword(s):  
Trace Metals ◽  
Current Knowledge ◽  
Cyanobacterial Bloom ◽  
Toxin Production ◽  
Cyanobacterial Blooms ◽  
Future Research ◽  
Limiting Factor ◽  
Bloom Formation ◽  
Wide Range

Cyanobacterial blooms are becoming more common in freshwater systems, causing ecological degradation and human health risks through exposure to cyanotoxins. The role of phosphorus and nitrogen in cyanobacterial bloom formation is well documented and these are regularly the focus of management plans. There is also strong evidence that trace metals are required for a wide range of cellular processes, however their importance as a limiting factor of cyanobacterial growth in ecological systems is unclear. Furthermore, some studies have suggested a direct link between cyanotoxin production and some trace metals. This review synthesises current knowledge on the following: (1) the biochemical role of trace metals (particularly iron, cobalt, copper, manganese, molybdenum and zinc), (2) the growth limitation of cyanobacteria by trace metals, (3) the trace metal regulation of the phytoplankton community structure and (4) the role of trace metals in cyanotoxin production. Iron dominated the literature and regularly influenced bloom formation, with 15 of 18 studies indicating limitation or colimitation of cyanobacterial growth. A range of other trace metals were found to have a demonstrated capacity to limit cyanobacterial growth, and these metals require further study. The effect of trace metals on cyanotoxin production is equivocal and highly variable. Better understanding the role of trace metals in cyanobacterial growth and bloom formation is an essential component of freshwater management and a direction for future research.

scholarly journals Evidence of Quorum Sensing in Cyanobacteria by Homoserine Lactones: The Origin of Blooms

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1831
Author(s):  
Natalia Herrera ◽  
Fernando Echeverri
Keyword(s):  
Cell Proliferation ◽  
Quorum Sensing ◽  
Microcystis Aeruginosa ◽  
Industrial Effluents ◽  
Cyanobacterial Blooms ◽  
Cylindrospermopsis Raciborskii ◽  
Bacterial Communication ◽  
Homoserine Lactones ◽  
Exogenous Compounds ◽  
Almost All

Although several theories have been postulated to explain cyanobacterial blooms, their biochemical origin has not yet been found. In this work, we explore the existence of bacterial communication, called quorum sensing, in Microcystis aeruginosa and Cylindrospermopsis raciborskii. Thus, the application of several known acylhomoserine lactones to cultures of both cyanobacteria causes profound metabolic. At 72 h post-application, some of them produced substantial increases in cell proliferation, while others were inhibitors. There was a correlation with colony-forming activity for most of them. According to ELISA analysis, the microcystin levels were increased with some lactones. However, there was a clear difference between M. aeruginosa and C. raciborskii culture since, in the first one, there was an inducing effect on cell proliferation, while in C. raciborskii, the effects were minor. Besides, there were compound inhibitors and inducers of microcystins production in M. aeruginosa, but almost all compounds were only inducers of saxitoxin production in C. raciborskii. Moreover, each lactone appears to be involved in a specific quorum sensing process. From these results, the formation of cyanobacterial blooms in dams and reservoirs could be explained since lactones may come from cyanobacteria and other sources as bacterial microflora-associated or exogenous compounds structurally unrelated to lactones, such as drugs, industrial effluents, and agrochemicals.

scholarly journals Effects of Malachite Green on the Microbiomes of Milkfish Culture Ponds

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 411
Author(s):  
Chu-Wen Yang ◽  
Yi-Tang Chang ◽  
Chi-Yen Hsieh ◽  
Bea-Ven Chang
Keyword(s):  
Infectious Diseases ◽  
Microbial Communities ◽  
Malachite Green ◽  
Fish Farming ◽  
Cyanobacterial Blooms ◽  
Anoxygenic Phototrophic Bacteria ◽  
Fish Mortality ◽  
Veterinary Drug ◽  
Degrading Bacteria ◽  
Microbial Infections

Intensive fish farming through aquaculture is vulnerable to infectious diseases that can increase fish mortality and damage the productivity of aquaculture farms. To prevent infectious diseases, malachite green (MG) has been applied as a veterinary drug for various microbial infections in aquaculture settings worldwide. However, little is known regarding the consequences of MG and MG-degrading bacteria (MGDB) on microbial communities in milkfish culture ponds (MCPs). In this study, small MCPs were used as a model system to determine the effects of MG on the microbial communities in MCPs. The addition of MG led to cyanobacterial blooms in the small MCP. The addition of MGDB could not completely reverse the effects of MG on microbial communities. Cyanobacterial blooms were not prevented. Microbial communities analyzed by next generation sequencing revealed that cyanobacterial blooms may be due to increase of nitrogen cycle (including nitrogen fixation, nitrate reduction and anammox) associated microbial communities, which raised the levels of ammonium in the water of the small MCP. The communities of anoxygenic phototrophic bacteria (beneficial for aquaculture and aquatic ecosystems) decreased after the addition of MG. The results of this investigation provide valuable insights into the effects of MG in aquaculture and the difficulties of bioremediation for aquatic environments polluted by MG.

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