Journal articles on the topic 'Cyanobacterial bloom'
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1
Rangel, Luciana M., Lúcia H. S. Silva, Elisabeth J. Faassen, Miquel Lürling, and Kemal Ali Ger. "Copepod Prey Selection and Grazing Efficiency Mediated by Chemical and Morphological Defensive Traits of Cyanobacteria." Toxins 12, no. 7 (July 21, 2020): 465. http://dx.doi.org/10.3390/toxins12070465.
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Phytoplankton anti-grazer traits control zooplankton grazing and are associated with harmful blooms. Yet, how morphological versus chemical phytoplankton defenses regulate zooplankton grazing is poorly understood. We compared zooplankton grazing and prey selection by contrasting morphological (filament length: short vs. long) and chemical (saxitoxin: STX- vs. STX+) traits of a bloom-forming cyanobacterium (Raphidiopsis) offered at different concentrations in mixed diets with an edible phytoplankton to a copepod grazer. The copepod selectively grazed on the edible prey (avoidance of cyanobacteria) even when the cyanobacterium was dominant. Avoidance of the cyanobacterium was weakest for the “short STX-” filaments and strongest for the other three strains. Hence, filament size had an effect on cyanobacterial avoidance only in the STX- treatments, while toxin production significantly increased cyanobacterial avoidance regardless of filament size. Moreover, cyanobacterial dominance reduced grazing on the edible prey by almost 50%. Results emphasize that the dominance of filamentous cyanobacteria such as Raphidiopsis can interfere with copepod grazing in a trait specific manner. For cyanobacteria, toxin production may be more effective than filament size as an anti-grazer defense against selectively grazing zooplankton such as copepods. Our results highlight how multiple phytoplankton defensive traits interact to regulate the producer-consumer link in plankton ecosystems.
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Wynne, Timothy T., Richard P. Stumpf, Kaytee L. Pokrzywinski, R. Wayne Litaker, Bart T. De Stasio, and Raleigh R. Hood. "Cyanobacterial Bloom Phenology in Green Bay Using MERIS Satellite Data and Comparisons with Western Lake Erie and Saginaw Bay." Water 14, no. 17 (August 26, 2022): 2636. http://dx.doi.org/10.3390/w14172636.
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Cyanobacteria blooms have been reported to be increasing worldwide. In addition to potentially causing major economic and ecological damage, these blooms can threaten human health. Furthermore, these blooms can be exacerbated by a warming climate. One approach to monitoring and modeling cyanobacterial biomass is to use processed satellite imagery to obtain long-term data sets. In this paper, an existing algorithm for estimating cyanobacterial biomass previously developed for MERIS is validated for Green Bay using cyanobacteria biovolume estimates obtained from field samples. Once the algorithm was validated, the existing MERIS imagery was used to determine the bloom phenology of the cyanobacterial biomass in Green Bay. Modeled datasets of heat flux (as a proxy for stratification), wind speed, water temperature, and gelbstoff absorption along with in situ river discharge data were used to separate bloom seasons in Green Bay from bloom seasons in nearby cyanobacteria bloom hotspots including western Lake Erie and Saginaw Bay. Of the ten-year MERIS dataset used here, the highest five years were considered “high bloom” years, and the lowest five years from biomass were considered “low bloom” years and these definitions were used to separate Green Bay. Green Bay had a strong relationship with gelbstoff absorption making it unique among the water bodies, while western Lake Erie responded strongly with river discharge as previously reported. Saginaw Bay, which has low interannual bloom variability, did not exhibit a largely influential single parameter.
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Sinang, S. C., E. S. Reichwaldt, and A. Ghadouani. "Local nutrient regimes determine site-specific environmental triggers of cyanobacterial and microcystin variability in urban lakes." Hydrology and Earth System Sciences Discussions 11, no. 10 (October 9, 2014): 11109–36. http://dx.doi.org/10.5194/hessd-11-11109-2014.
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Abstract. Toxic cyanobacterial blooms in urban lakes present serious health hazards to humans and animals and require effective management strategies. In the management of toxic cyanobacteria blooms, understanding the roles of environmental factors is crucial. To date, a range of environmental factors have been proposed as potential triggers for the spatiotemporal variability of cyanobacterial biomass and microcystins in freshwater systems. However, the environmental triggers of cyanobacteria and microcystin variability remain a subject of debate due to contrasting findings. This issue has raised the question if the environmental triggers are site-specific and unique between water bodies. In this study, we investigated the site-specificity of environmental triggers for cyanobacterial bloom and cyanotoxins dynamics. Our study suggests that cyanobacterial dominance and cyanobacterial microcystin content variability were significantly correlated to phosphorus and iron concentrations. However, the correlations between phosphorus and iron with cyanobacterial biomass and microcystin variability were not consistent between lakes, thus suggesting a site specificity of these environmental factors. The discrepancies in the correlations could be explained by differences in local nutrient concentration and the cyanobacterial community in the systems. The findings of this study suggest that identification of site-specific environmental factors under unique local conditions is an important strategy to enhance positive outcomes in cyanobacterial bloom control measures.
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Gu, Zheng Di. "Life Cycle of Bloom-Forming Cyanobacteria and its Influencing Factors." Applied Mechanics and Materials 209-211 (October 2012): 1227–30. http://dx.doi.org/10.4028/www.scientific.net/amm.209-211.1227.
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Many eutrophic lakes are threatened by cyanobacterial blooms. The bloom-forming cyanobacteria are capable of nuisance growth and produce toxins, resulting in serious threats to water safety and human health. This paper summarized physiological and ecological characteristics of bloom-forming cyanobacteria in their annual life cycle, internal regulation mechanisms and environmental factors for blooms formation. In winter, dormant period is regarded as the continuation of cyanobacteria populations, which conserve “seed bank” for the following year. In spring, recruitment can be defined as an inoculation of overwintering cyanobacteria to the pelagic phase after growth recovery under suitable conditions. Temperature, resuspension and bioturbation had been recognized to be the main driving factors for recruitment. Shortly after recruitment, cyanobacteria establish dominance by fast growth rate and colony enlargement strategy. Under suitable meteorological and hydrological conditions, cyanobacterial colonies aggregate and float up to form heavy blooms, which can lead to water supply crisis and ecological disaster. From late autumn, blooms disaggregate and decline. The sinking process is not only a periodic life cycle but also an irregular mechanical movement. Cyanobacteria accumulation areas in late autumn might highly related to the first occurence locality of blooms in the following year. This information could provide valuable information for the prediction and prevention of cyanobacterial blooms, so as to establish a more stable and healthy ecosystem in lakes.
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Ji, Xing, Jolanda M. H. Verspagen, Dedmer B. Van de Waal, Björn Rost, and Jef Huisman. "Phenotypic plasticity of carbon fixation stimulates cyanobacterial blooms at elevated CO2." Science Advances 6, no. 8 (February 2020): eaax2926. http://dx.doi.org/10.1126/sciadv.aax2926.
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Although phenotypic plasticity is a widespread phenomenon, its implications for species responses to climate change are not well understood. For example, toxic cyanobacteria can form dense surface blooms threatening water quality in many eutrophic lakes, yet a theoretical framework to predict how phenotypic plasticity affects bloom development at elevated pCO2 is still lacking. We measured phenotypic plasticity of the carbon fixation rates of the common bloom-forming cyanobacterium Microcystis. Our results revealed a 1.8- to 5-fold increase in the maximum CO2 uptake rate of Microcystis at elevated pCO2, which exceeds CO2 responses reported for other phytoplankton species. The observed plasticity was incorporated into a mathematical model to predict dynamic changes in cyanobacterial abundance. The model was successfully validated by laboratory experiments and predicts that acclimation to high pCO2 will intensify Microcystis blooms in eutrophic lakes. These results indicate that this harmful cyanobacterium is likely to benefit strongly from rising atmospheric pCO2.
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Larsen, Megan L., Helen M. Baulch, Sherry L. Schiff, Dana F. Simon, Sébastien Sauvé, and Jason J. Venkiteswaran. "Extreme rainfall drives early onset cyanobacterial bloom." FACETS 5, no. 1 (January 1, 2020): 899–920. http://dx.doi.org/10.1139/facets-2020-0022.
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The increasing prevalence of cyanobacteria-dominated harmful algal blooms is strongly associated with nutrient loading and changing climatic patterns. Changes to precipitation frequency and intensity, as predicted by current climate models, are likely to affect bloom development and composition through changes in nutrient fluxes and water column mixing. However, few studies have directly documented the effects of extreme precipitation events on cyanobacterial composition, biomass, and toxin production. We tracked changes in a eutrophic reservoir following an extreme precipitation event, describing an atypically early toxin-producing cyanobacterial bloom and successional progression of the phytoplankton community, toxins, and geochemistry. An increase in bioavailable phosphorus by more than 27-fold in surface waters preceded notable increases in Aphanizomenon flos-aquae throughout the reservoir approximately 2 weeks postevent and ∼5 weeks before blooms typically occur. Anabaenopeptin-A and three microcystin congeners (microcystin-LR, -YR, and -RR) were detected at varying levels across sites during the bloom period, which lasted between 3 and 5 weeks. These findings suggest extreme rainfall can trigger early cyanobacterial bloom initiation, effectively elongating the bloom season period of potential toxicity. However, effects will vary depending on factors including the timing of rainfall and reservoir physical structure.
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Zong, Jia-Min, Xin-Xin Wang, Qiao-Yan Zhong, Xiang-Ming Xiao, Jun Ma, and Bin Zhao. "Increasing Outbreak of Cyanobacterial Blooms in Large Lakes and Reservoirs under Pressures from Climate Change and Anthropogenic Interferences in the Middle–Lower Yangtze River Basin." Remote Sensing 11, no. 15 (July 25, 2019): 1754. http://dx.doi.org/10.3390/rs11151754.
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In recent decades, the increasing frequency and severity of cyanobacterial blooms in recreational lakes and water supply reservoirs have become a great concern to public health and a significant threat to the environment. Cyanobacterial bloom monitoring is the basis of early warning and treatment. Previous research efforts have always focused on monitoring blooms in a few specific lakes in China using moderate resolution imaging spectroradiometer (MODIS) images, which are available for the years 2000 onward. However, the lack of overall information on long-term cyanobacterial blooms in the lakes and reservoirs in the middle–lower Yangtze River (MLYR) basin is an obstacle to better understanding the dynamics of cyanobacterial blooms at a watershed scale. In this study, we extracted the yearly coverage area and frequency of cyanobacterial blooms that occurred from 1990 to 2016 in 30 large lakes and 10 reservoirs (inundation area >50 km2) by using time series Landsat satellite images from Google Earth Engine (GEE). Then, we calculated the cyanobacterial bloom area percentage (CAP) and the cyanobacterial bloom frequency index (CFI) and analyzed their inter-annual variation and trends. We also investigated the main driving forces of changes in the CAP and CFI in each lake and reservoir. We found that all reservoirs and more than 60% of lakes exhibited an increasing frequency and coverage area of cyanobacterial blooms under the pressures of climate change and anthropogenic interferences. Reservoirs were more prone to be affected by fertilizer consumption from their regional surroundings than lakes. High temperatures increased blooms of cyanobacteria, while precipitation in the lake and reservoir regions somewhat alleviated blooms. This study completes the data records of cyanobacterial blooms in large lakes and reservoirs located in hotspots of the MLYR basin and provides more baseline information before 2000, which will present references for water resource management and freshwater conservation.
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Fuentes, Norka, Catalina Ríos-Henríquez, and Patricio A. Díaz. "Hydroclimatic drivers associated with an unusual bloom of Microcystis aeruginosa and increase of CyanoHABs in a deep oligotrophic lake." Journal of Plankton Research 44, no. 1 (November 18, 2021): 68–72. http://dx.doi.org/10.1093/plankt/fbab079.
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Abstract Hydroclimatic and anthropogenic factors in climate change scenarios contribute to ecological changes of harmful cyanobacterial algal blooms in lakes. This study describes the variability of the bathymetric and temporal distribution of cyanobacterial communities in a deep oligotrophic lake. An increase of two to nine in the detection of CyanoHABs potential was observed, likely linked to nitrogen contributions to Lake Rupanco during the last 36 years related to changes in land use and the cultivation of salmonids. We recorded an unusual bloom of Microcystis aeruginosa in winter, 2017 at 30 m during the total mixing period of the lake, associated with the highest N/P index (16.24), the increase of total nitrogen (75 μg/L) and climatic conditions that favored the availability of nitrogen of this cyanobacterium. This study provides information on the causes of increased cyanobacteria in a deep oligotrophic lake. Long-term information on the composition of cyanobacterial communities is very helpful in determining ecological changes.
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Nowicka-Krawczyk, Paulina, Joanna Żelazna-Wieczorek, Izabela Skrobek, Maciej Ziułkiewicz, Michał Adamski, Ariel Kaminski, and Paweł Żmudzki. "Persistent Cyanobacteria Blooms in Artificial Water Bodies—An Effect of Environmental Conditions or the Result of Anthropogenic Change." International Journal of Environmental Research and Public Health 19, no. 12 (June 7, 2022): 6990. http://dx.doi.org/10.3390/ijerph19126990.
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Algal blooms are an emerging problem. The massive development of phytoplankton is driven partly by the anthropogenic eutrophication of aquatic ecosystems and the expansion of toxic cyanobacteria in planktonic communities in temperate climate zones by the continual increase in global temperature. Cyanobacterial harmful algal blooms (CyanoHABs) not only disturb the ecological balance of the ecosystem, but they also prevent the use of waterbodies by humans. This study examines the cause of an unusual, persistent bloom in a recreational, flow-through reservoir; the findings emphasize the role played by the river supplying the reservoir in the formation of its massive cyanobacterial bloom. Comprehensive ecosystem-based environmental studies were performed, including climate change investigation, hydrochemical analysis, and bio-assessment of the ecological state of the river/reservoir, together with monitoring the cyanobacteria content of phytoplankton. Our findings show that the persistent and dominant biomass of Microcystis was related to the N/P ratio, while the presence of Aphanizomenon and Dolichospermum was associated with the high-temperature end electric conductivity of water. Together with the increase in global temperature, the massive and persistent cyanobacterial bloom appears to be maintained by the inflow of biogenic compounds carried by the river and the high electric conductivity of water. Even at the beginning of the phenomenon, the reservoir water already contained cyanobacterial toxins, which excluded its recreational use for about half the year.
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Codd, G. A. "Cyanobacterial toxins: occurrence, properties and biological significance." Water Science and Technology 32, no. 4 (August 1, 1995): 149–56. http://dx.doi.org/10.2166/wst.1995.0177.
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All of the most commonly encountered genera of cyanobacteria which form blooms and scums in fresh-brackish- and marine waters include members capable of producing potent toxins. Poisonings of vertebrate and invertebrate animals following the ingestion of cyanobacterial bloom/scum material have been widely reported for many years and recognition of the adverse effects of cyanobacterial blooms and their toxins is increasing. This review considers the occurrence of toxic cyanobacterial populations and properties of the toxins themselves, of which at least 60 are now recognised. When rightfully regarded as microbial secondary metabolites, a range of possible functions for cyanobacterial toxins is presented. Whether cyanobacterial toxins contribute to the ability of cyanobacteria to dominate many eutrophic waterbodies is unknown, although understanding of the occurrence of the toxins in aquatic environments and their actions at the molecular level and with whole organisms in laboratory studies indicates that this is possible.
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Mishra, Sonal, Neha Kumari, Donat-P. Häder, and Rajeshwar P. Sinha. "Cyanobacterial Blooms and Their Implications in the Changing Environment." Advances in Environmental and Engineering Research 3, no. 1 (January 3, 2022): 1. http://dx.doi.org/10.21926/aeer.2201011.
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Cyanobacteria are the most ancient phytoplankton that first appeared at least 2.5 billion years ago and have a prolonged evolutionary history. They can form impenetrable and toxic blooms in aquatic ecosystems such as freshwater and marine environments. Cyanobacterial blooms produce cyanotoxins that endanger ecosystem functioning and deteriorate water quality used for recreation, drinking, and in fisheries, thus, adversely affecting human health and the economy. Some bloom-producing genera are Aphanizomenon, Planktothrix, Cylindrospermopsis, Nodularia, Trichodesmium, Dolichospermum, and Microcystis. They increase turbidity and suppress submerged aquatic vegetation. Due to the microbial bloom-mediated environmental degradation, oxygen scarcity might occur, inducing hypoxia and anoxia, and resulting in the death of fish and benthic invertebrates. Several cyanotoxins cause many diseases related to digestion, liver, and neurological disorders when ingested by birds and mammals, including humans. Global changes resulting from human impacts like eutrophication, rising CO2 levels, and global warming are major driving forces for the enhancement of cyanobacterial blooms in many aquatic systems worldwide. Various management strategies such as nutrient load reduction, hydrodynamic changes, and chemical and biological controls have been used to reduce bloom occurrence and proliferation of cyanobacteria. In this chapter, we have discussed the approaches regarding the understanding of how global changes affect cyanobacterial blooms and also suggested effective prediction and management strategies.
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Vanderley, Rayane F., Kemal A. Ger, Vanessa Becker, Maria Gabriela T. A. Bezerra, and Renata Panosso. "Abiotic factors driving cyanobacterial biomass and composition under perennial bloom conditions in tropical latitudes." Hydrobiologia 848, no. 4 (January 18, 2021): 943–60. http://dx.doi.org/10.1007/s10750-020-04504-7.
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AbstractWhile warming and eutrophication have increased the frequency and magnitude of harmful cyanobacterial blooms globally, the scenario for many eutrophic tropical freshwaters is a perennial year-round bloom. Yet, the drivers of persistent blooms are less understood when conditions such as light, temperature, and nutrients favor cyanobacteria growth year-round, and especially in regions facing recurrent periods of drought. In order to understand the drivers of cyanobacteria dominance, we assessed the abiotic conditions related to the abundance and dominance of the two dominant bloom-forming genera Raphidiopsis and Microcystis, in six shallow, man-made lakes located in the semiarid Northeastern region of Brazil during a prolonged regional drought. Lower water level corresponded to increased phosphorous and nitrogen concentration and, consequently, phytoplankton biomass. Cyanobacterial biomass was also proportional to phosphorus concentrations during year-round blooms. Yet, the two dominant cyanobacterial genera, Raphidiopsis and Microcystis, seldom co-occurred temporally and the switch between them was driven by water transparency. Our results illustrate the effects of drought induced water level reductions on the biomass and composition of cyanobacterial blooms in tropical shallow man-made lakes. Given the ideal year-round conditions (i.e., high light and temperature), droughts may be expected to intensify the risk and multitude of problems associated with eutrophication.
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Tsyrenova, D. D., S. V. Zaitseva, O. P. Dagurova, V. B. Dambaev, and D. D. Barkhutova. "Cyanobacteria in freshwater Lake Dikoye (Pribaikalsky district, Buryatia, Siberia) under intensive eutrophication." IOP Conference Series: Earth and Environmental Science 908, no. 1 (November 1, 2021): 012009. http://dx.doi.org/10.1088/1755-1315/908/1/012009.
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Abstract We studied freshwater Lake Dikoye located in the coastal zone of Lake Baikal. Negative changes associated with cyanobacterial bloom were observed in the lake. Phototrophs were represented by cyanobacteria, green algae, and diatoms. In the microbial community, Cyanobacteria were the dominant phylum and accounted for up to 48% of the total diversity. Cyanobacteria were represented by 7 genera and 9 species. Microcystis aeruginosa, a potentially toxic species, was dominant among cyanobacteria. According to chlorophyll a content, the lake should be assigned to eutrophic ones. The bacterial eutrophication index for the lake studied varied from 1.17 (middle eutrophic) to 28.2 (hypereutrophic) during cyanobacterial bloom.
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Wang, Mengmeng, Huifen Zhang, Menggaoshan Chen, Liuyan Yang, and Yichen Yang. "Dark accelerates dissolved inorganic phosphorus release of high-density cyanobacteria." PLOS ONE 15, no. 12 (December 22, 2020): e0243582. http://dx.doi.org/10.1371/journal.pone.0243582.
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Bloom-forming cyanobacteria dramatically influence nutrient cycling in eutrophic freshwater lakes. The phosphorus (P) assimilation and release of bloom-forming cyanobacteria significantly may also affect the phosphorus source and amounts in water. To understand the phosphorus release process of bloom-forming cyanobacteria below the accumulated surface and sedimentary bloom-forming cyanobacteria, the degradation of bloom-forming cyanobacteria dominated by Microcystis spp. at different cell density in the dark was investigated over a 25-day microcosm experiment. The dissolved inorganic phosphorus (DIP) and dissolved total phosphorus (DTP) contents increased with the increment of cyanobacterial density, and the dark status markedly increased the proportion of DIP in water during the decline period of bloom-forming cyanobacteria. Meanwhile, the process of cyanobacterial apoptosis accompanied by the changes of malondialdehyde (MDA) and phosphatase (AKP) contents, and the increases of superoxide dismutase (SOD) and catalase (CAT) activities of cyanobacteria in the dark, especially in low-density groups (5.23×108 cells L-1), which further affect the physicochemical water parameters. Moreover, the DIP release from high-density cyanobacteria (7.86×107 cells L-1~5.23×108 cells L-1) resulted from the relative abundance of organophosphorus degrading bacteria in the dark. Therefore, the fast decay of cyanobacteria in the dark could accelerate DIP release, the high DIP release amount from accumulated bloom-cyanobacteria provide adequate P quickly for the sustained growth of cyanobacteria.
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Li, Jingtai, Yao Liu, Siying Xie, Min Li, Li Chen, Cuiling Wu, Dandan Yan, and Zhaoqing Luan. "Landsat-Satellite-Based Analysis of Long-Term Temporal Spatial Dynamics of Cyanobacterial Blooms: A Case Study in Taihu Lake." Land 11, no. 12 (December 4, 2022): 2197. http://dx.doi.org/10.3390/land11122197.
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Cyanobacterial blooms in large and shallow freshwater lakes have become one of the most severe ecological problems threatening the environment and public health. Although great progress has been made in Taihu Lake in cyanobacterial bloom monitoring, most previous studies have used MODIS images with a resolution greater than 250 m, available after 2000, while the fine-scale studies on its long-term spatio-temporal dynamics to date are insufficient. This study monitored the spatiotemporal distribution of cyanobacterial blooms in Taihu Lake between 1984 and 2021 using Landsat images of 30 m resolution on the cloud computation platform Google Earth Engine and calculated the cyanobacterial blooms’ area percentage and the cyanobacterial bloom frequency index. Then, we investigated the influence of water quality and meteorological factors on area and frequency using Spearman correlation and principal component analysis. The results show that cyanobacterial blooms spread from the northern to the central, western, and eastern parts of Taihu Lake from 1984 to 2021. With the exception of East Lake, the area and frequency of cyanobacterial blooms increased significantly. Hypereutrophic water conditions, high temperatures, abundant sunshine hours, and low wind velocities all favor cyanobacteria blooms in Taihu Lake, and the key influencing factors of dynamics in cyanobacterial blooms are the comprehensive trophic level index, annual sunshine hours, and annual maximum wind speed. This study can serve as a reference for lake eutrophication monitoring and water resource management and protection.
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Srivastava, Ankita, Chi-Yong Ahn, Ravi Kumar Asthana, Hyung-Gwan Lee, and Hee-Mock Oh. "Status, Alert System, and Prediction of Cyanobacterial Bloom in South Korea." BioMed Research International 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/584696.
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Bloom-forming freshwater cyanobacterial genera pose a major ecological problem due to their ability to produce toxins and other bioactive compounds, which can have important implications in illnesses of humans and livestock. Cyanobacteria such asMicrocystis, Anabaena, Oscillatoria, Phormidium, andAphanizomenonspecies producing microcystins and anatoxin-a have been predominantly documented from most South Korean lakes and reservoirs. With the increase in frequency of such blooms, various monitoring approaches, treatment processes, and prediction models have been developed in due course. In this paper we review the field studies and current knowledge on toxin producing cyanobacterial species and ecological variables that regulate toxin production and bloom formation in major rivers (Han, Geum, Nakdong, and Yeongsan) and reservoirs in South Korea. In addition, development of new, fast, and high-throughput techniques for effective monitoring is also discussed with cyanobacterial bloom advisory practices, current management strategies, and their implications in South Korean freshwater bodies.
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Giannuzzi, Leda, Julián Bacciadone, and Graciela L. Salerno. "A Promising Use of Trimethyl Chitosan for Removing Microcystis aeruginosa in Water Treatment Processes." Microorganisms 10, no. 10 (October 18, 2022): 2052. http://dx.doi.org/10.3390/microorganisms10102052.
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The increase in cyanobacterial blooms linked to climate change and the eutrophication of water bodies is a global concern. The harmful cyanobacterium Microcystis aeruginosa is one of the most common bloom-forming species whose removal from fresh water and, in particular, from that used for water treatment processes, remains a crucial goal. Different biodegradable and environmentally friendly coagulants/flocculants have been assayed, with chitosan showing a very good performance. However, chitosan in its original form is of limited applicability since it is only soluble in acid solution. The objective of this work was therefore to test the coagulant/flocculant capacity of trimethylchitosan (TMC), a chitosan derivative produced from residues of the fishing industry. TMC has a constitutively net positive charge enabling it to remain in solution regardless of the pH. Results show that even at alkaline pHs, common during cyanobacterial blooms, TMC is effective in removing buoyant cyanobacteria from the water column, both in test tube and Jar-Test experiments. Cell integrity was confirmed by fluorescent stain and electron microscopy. Our findings lead us to conclude that the use of TMC to remove bloom cells early in the treatment of drinking water is both feasible and promising.
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Zakeel, M. C. M., P. A. Weerasinghe, H. C. D. Wijayawardhana, and B. A. D. G. Kumari. "Preliminary Study to Find Occurrence and Dynamics of Toxic Cyanobacteria in Nuwara wewa and Nachchaduwa wewa, Two Man-made Reservoirs in Sri Lanka." International Journal for Innovation Education and Research 6, no. 5 (May 31, 2018): 179–91. http://dx.doi.org/10.31686/ijier.vol6.iss5.1040.
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Bloom of cyanobacteria in water bodies causes devastating problems to the ecosystem and humans when they depend on these waters for drinking purpose. Microcystin and nodularin, produced by some cyanobacteria, are toxic for human and many other aquatic organisms. Nuwara wewa and Nachchaduwa wewa are two important reservoirs supplying water for drinking purpose in addition to agricultural use. Therefore, preliminary study was conducted to evaluate these reservoirs for the presence of toxic cyanobacteria and their dynamics is of importance to take proper measures to control cyanobacterial growth and to ensure supply of quality water for human drinking purpose. Water samples were collected for 12 months from both reservoirs and physic-chemicals parameters of water were also recorded. Correlations between the physico-chemical parameters of water and the cyanobacterial density were established. Toxic cyanobacteria were isolated and identified using conventional and molecular methods. 16S rRNA gene and mcy-A gene were targeted for molecular identification using PCR. Cyanobacterial density had strong positive correlations with some physico-chemical parameters such as pH, temperature and dissolved oxygen in both reservoirs. These parameters can be used as good indicators to evaluate the condition these reservoirs with respect to cyanobacterial bloom. Some cyanobacterial isolates recovered from both reservoirs harboured mcy-A gene, showing the potential of microcystin production.
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Facey, Jordan A., Simon C. Apte, and Simon M. Mitrovic. "A Review of the Effect of Trace Metals on Freshwater Cyanobacterial Growth and Toxin Production." Toxins 11, no. 11 (November 5, 2019): 643. http://dx.doi.org/10.3390/toxins11110643.
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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.
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Jalili, Farhad, Hana Trigui, Juan Francisco Guerra Maldonado, Sarah Dorner, Arash Zamyadi, B. Jesse Shapiro, Yves Terrat, Nathalie Fortin, Sébastien Sauvé, and Michèle Prévost. "Can Cyanobacterial Diversity in the Source Predict the Diversity in Sludge and the Risk of Toxin Release in a Drinking Water Treatment Plant?" Toxins 13, no. 1 (January 1, 2021): 25. http://dx.doi.org/10.3390/toxins13010025.
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Conventional processes (coagulation, flocculation, sedimentation, and filtration) are widely used in drinking water treatment plants and are considered a good treatment strategy to eliminate cyanobacterial cells and cell-bound cyanotoxins. The diversity of cyanobacteria was investigated using taxonomic cell counts and shotgun metagenomics over two seasons in a drinking water treatment plant before, during, and after the bloom. Changes in the community structure over time at the phylum, genus, and species levels were monitored in samples retrieved from raw water (RW), sludge in the holding tank (ST), and sludge supernatant (SST). Aphanothece clathrata brevis, Microcystis aeruginosa, Dolichospermum spiroides, and Chroococcus minimus were predominant species detected in RW by taxonomic cell counts. Shotgun metagenomics revealed that Proteobacteria was the predominant phylum in RW before and after the cyanobacterial bloom. Taxonomic cell counts and shotgun metagenomic showed that the Dolichospermum bloom occurred inside the plant. Cyanobacteria and Bacteroidetes were the major bacterial phyla during the bloom. Shotgun metagenomics also showed that Synechococcus, Microcystis, and Dolichospermum were the predominant detected cyanobacterial genera in the samples. Conventional treatment removed more than 92% of cyanobacterial cells but led to cell accumulation in the sludge up to 31 times more than in the RW influx. Coagulation/sedimentation selectively removed more than 96% of Microcystis and Dolichospermum. Cyanobacterial community in the sludge varied from raw water to sludge during sludge storage (1–13 days). This variation was due to the selective removal of coagulation/sedimentation as well as the accumulation of captured cells over the period of storage time. However, the prediction of the cyanobacterial community composition in the SST remained a challenge. Among nutrient parameters, orthophosphate availability was related to community profile in RW samples, whereas communities in ST were influenced by total nitrogen, Kjeldahl nitrogen (N- Kjeldahl), total and particulate phosphorous, and total organic carbon (TOC). No trend was observed on the impact of nutrients on SST communities. This study profiled new health-related, environmental, and technical challenges for the production of drinking water due to the complex fate of cyanobacteria in cyanobacteria-laden sludge and supernatant.
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Puyana, Mónica, Alberto Acosta, Katherine Bernal-Sotelo, Trigal Velásquez-Rodríguez, and Freddy Ramos. "Spatial scale of cyanobacterial blooms in Old Providence Island, Colombian Caribbean." Universitas Scientiarum 20, no. 1 (August 31, 2014): 83. http://dx.doi.org/10.11144/javeriana.sc20-1.sscb.
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The frequency and expansion of cyanobacterial blooms have increased in coastal waters worldwide. These may be facilitated by excessive nutrient input and global warming, exerting negative consequences in marine ecosystems, communities and habitats. Although reports of cyanobacterial blooms are frequent, their causes, consequences and spatial extent are not completely understood, hence restricting regional management actions. From 2009 to 2012 we examined the spatial extent of cyanobacterial blooms in the reef systems off Providencia Island, Colombia. We also identified the main taxa involved in those blooms and evaluated bloom cover within substrate types. Blooms of benthic cyanobacteria consisted of complex microbial consortia belonging to the genera Okeania, Lyngbya, Symploca, Phormidium, Oscillatoria or Spirulina. Cyanobacteria were present in different ecosystems, geomorphological zones and substrate types, particularly at the northwest, east and southeast portions of the island. The soft bottoms, sea grasses and reef ecosystems around Providencia Island are subject to cyanobacterial blooms of varying intensity. There is a strong need to further study the frequency, scale and duration of these events to understand their impact on an ecosystem basis and on the services these provide.
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Lee, Bokjin, Heejun Kang, Hye-cheol Oh, Jaehwan Ahn, Saerom Park, Sang-Leen Yun, and Seogku Kim. "Long-Term Examination of Water Chemistry Changes Following Treatment of Cyanobacterial Bloom with Coagulants and Minerals." International Journal of Environmental Research and Public Health 19, no. 20 (October 20, 2022): 13577. http://dx.doi.org/10.3390/ijerph192013577.
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The abundant growth in cyanobacterial blooms poses severe ecological threats with a high risk to aquatic organisms and global public health. Control of cyanobacterial blooms involves spraying cyanobacteria removal materials, including coagulants. However, little is known about the fate of the coagulated-cyanobacteria-laden water. Here, we examined long-term changes in water quality following treatment with various coagulants and minerals for cyanobacterial removal when the coagulated cyanobacterial cells were not removed from the water. An experiment in a controlled water system tested the effects of six different compounds, one conventional coagulant, two natural inorganic coagulants, and three minerals. All tested coagulants and minerals exhibited >75% of cyanobacterial removal efficiency. However, compared to the control, higher concentrations of nitrogen were observed from some samples treated during the experimental period. After 20 months, the final total phosphorus concentration of the raw water increased 20-fold compared to the initial concentration to 11.82 mg/L, indicating significant nutrient release over time. Moreover, we observed that the decomposition of sedimented cyanobacterial cells caused the release of intracellular contents into the supernatant, increasing phosphorous concentration over time. Therefore, cyanobacterial cells should be removed from water after treatment to prevent eutrophication and maintain water quality.
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Valadez-Cano, Cecilio, Kristen Hawkes, Rossella Calvaruso, Adrian Reyes-Prieto, and Janice Lawrence. "Amplicon-based and metagenomic approaches provide insights into toxigenic potential in understudied Atlantic Canadian lakes." FACETS 7 (January 1, 2022): 194–214. http://dx.doi.org/10.1139/facets-2021-0109.
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Cyanobacterial blooms and their toxigenic potential threaten freshwater resources worldwide. In Atlantic Canada, despite an increase of cyanobacterial blooms in the last decade, little is known about the toxigenic potential and the taxonomic affiliation of bloom-forming cyanobacteria. In this study, we employed polymerase chain reaction (PCR) and metagenomic approaches to assess the potential for cyanotoxin and other bioactive metabolite production in Harvey Lake (oligotrophic) and Washademoak Lake (mesotrophic) in New Brunswick, Canada, during summer and early fall months. The PCR survey detected the potential for microcystin (hepatotoxin) and anatoxin-a (neurotoxin) production in both lakes, despite a cyanobacterial bloom only being visible in Washademoak. Genus-specific PCR associated microcystin production potential with the presence of Microcystis in both lakes. The metagenomic strategy provided insight into temporal variations in the microbial communities of both lakes. It also permitted the recovery of a near-complete Microcystis aeruginosa genome with the genetic complement to produce microcystin and other bioactive metabolites such as piricyclamide, micropeptin/cyanopeptolin, and aeruginosin. Our approaches demonstrate the potential for production of a diverse complement of bioactive compounds and establish important baseline data for future studies of understudied lakes, which are frequently affected by cyanobacterial blooms.
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Stuparyk, Blake R., Mark Graham, Jenna Cook, Mitchell A. Johnsen, Karen K. Christensen-Dalsgaard, and Rolf D. Vinebrooke. "Experimental culling of minnows suppresses cyanobacterial bloom under low-nutrient conditions." Canadian Journal of Fisheries and Aquatic Sciences 76, no. 11 (November 2019): 2102–9. http://dx.doi.org/10.1139/cjfas-2018-0396.
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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.
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Huo, Yan, Yuanze Li, Wei Guo, Jin Liu, Cuiping Yang, Lin Li, Haokun Liu, and Lirong Song. "Evaluation of Cyanobacterial Bloom from Lake Taihu as a Protein Substitute in Fish Diet—A Case Study on Tilapia." Toxins 13, no. 10 (October 19, 2021): 735. http://dx.doi.org/10.3390/toxins13100735.
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The utility of cyanobacterial bloom is often hindered by concerns about the toxin content. Over three years of investigation, we found that the toxin content of cyanobacterial bloom in Lake Taihu was always low in June and higher in late summer and autumn. The findings enabled us to compare the effects of diets containing low and high toxic cyanobacterial blooms on the growth and consumption safety of tilapia. There were no negative effects on the growth of tilapia, and the muscle seemed to be safe for human consumption in the treatment of 18.5% low toxic cyanobacterial bloom. Therefore, limitations of the utilization of cyanobacterial biomass can be overcome by selecting low toxic cyanobacterial bloom that can be found and collected in large lakes.
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Moffitt, Michelle C., and Brett A. Neilan. "Characterization of the Nodularin Synthetase Gene Cluster and Proposed Theory of the Evolution of Cyanobacterial Hepatotoxins." Applied and Environmental Microbiology 70, no. 11 (November 2004): 6353–62. http://dx.doi.org/10.1128/aem.70.11.6353-6362.2004.
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ABSTRACT Nodularia spumigena is a bloom-forming cyanobacterium which produces the hepatotoxin nodularin. The complete gene cluster encoding the enzymatic machinery required for the biosynthesis of nodularin in N. spumigena strain NSOR10 was sequenced and characterized. The 48-kb gene cluster consists of nine open reading frames (ORFs), ndaA to ndaI, which are transcribed from a bidirectional regulatory promoter region and encode nonribosomal peptide synthetase modules, polyketide synthase modules, and tailoring enzymes. The ORFs flanking the nda gene cluster in the genome of N. spumigena strain NSOR10 were identified, and one of them was found to encode a protein with homology to previously characterized transposases. Putative transposases are also associated with the structurally related microcystin synthetase (mcy) gene clusters derived from three cyanobacterial strains, indicating a possible mechanism for the distribution of these biosynthetic gene clusters between various cyanobacterial genera. We propose an alternative hypothesis for hepatotoxin evolution in cyanobacteria based on the results of comparative and phylogenetic analyses of the nda and mcy gene clusters. These analyses suggested that nodularin synthetase evolved from a microcystin synthetase progenitor. The identification of the nodularin biosynthetic gene cluster and evolution of hepatotoxicity in cyanobacteria reported in this study may be valuable for future studies on toxic cyanobacterial bloom formation. In addition, an appreciation of the natural evolution of nonribosomal biosynthetic pathways will be vital for future combinatorial engineering and rational design of novel metabolites and pharmaceuticals.
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Sinang, S. C., E. S. Reichwaldt, and A. Ghadouani. "Local nutrient regimes determine site-specific environmental triggers of cyanobacterial and microcystin variability in urban lakes." Hydrology and Earth System Sciences 19, no. 5 (May 7, 2015): 2179–95. http://dx.doi.org/10.5194/hess-19-2179-2015.
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Abstract. Toxic cyanobacterial blooms in urban lakes present serious health hazards to humans and animals and require effective management strategies. Managing such blooms requires a sufficient understanding of the controlling environmental factors. A range of them has been proposed in the literature as potential triggers for cyanobacterial biomass development and cyanotoxin (e.g. microcystin) production in freshwater systems. However, the environmental triggers of cyanobacteria and microcystin variability remain a subject of debate due to contrasting findings. This issue has raised the question of whether the relevance of environmental triggers may depend on site-specific combinations of environmental factors. In this study, we investigated the site-specificity of environmental triggers for cyanobacterial bloom and microcystin dynamics in three urban lakes in Western Australia. Our study suggests that cyanobacterial biomass, cyanobacterial dominance and cyanobacterial microcystin content variability were significantly correlated to phosphorus and iron concentrations. However, the correlations were different between lakes, thus suggesting a site-specific effect of these environmental factors. The discrepancies in the correlations could be explained by differences in local nutrient concentration. For instance, we found no correlation between cyanobacterial fraction and total phosphorous (TP) in the lake with the highest TP concentration, while correlations were significant and negative in the other two lakes. In addition, our study indicates that the difference of the correlation between total iron (TFe) and the cyanobacterial fraction between lakes might have been a consequence of differences in the cyanobacterial community structure, specifically the presence or absence of nitrogen-fixing species. In conclusion, our study suggests that identification of significant environmental factors under site-specific conditions is an important strategy to enhance successful outcomes in cyanobacterial bloom control measures.
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Riba, Milán, Attila Kiss-Szikszai, Sándor Gonda, Gergely Boros, Zoltán Vitál, Andrea Kériné Borsodi, Gergely Krett, Gábor Borics, Andrea Zsuzsanna Ujvárosi, and Gábor Vasas. "Microcystis Chemotype Diversity in the Alimentary Tract of Bigheaded Carp." Toxins 11, no. 5 (May 22, 2019): 288. http://dx.doi.org/10.3390/toxins11050288.
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Most cyanobacterial organisms included in the genus Microcystis can produce a wide repertoire of secondary metabolites. In the mid-2010s, summer cyanobacterial blooms of Microcystis sp. occurred regularly in Lake Balaton. During this period, we investigated how the alimentary tract of filter-feeding bigheaded carps could deliver different chemotypes of viable cyanobacteria with specific peptide patterns. Twenty-five Microcystis strains were isolated from pelagic plankton samples (14 samples) and the hindguts of bigheaded carp (11 samples), and three bloom samples were collected from the scums of cyanobacterial blooms. An LC-MS/MS-based untargeted approach was used to analyze peptide patterns, which identified 36 anabaenopeptin, 17 microginin, and 13 microcystin variants. Heat map clustering visualization was used to compare the identified chemotypes. A lack of separation was observed in peptide patterns of Microcystis that originated from hindguts, water samples, and bloom-samples. Except for 13 peptides, all other congeners were detected from the viable and cultivated chemotypes of bigheaded carp. This finding suggests that the alimentary tract of bigheaded carps is not simply an extreme habitat, but may also supply the cyanobacterial strains that represent the pelagic chemotypes.
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Kim, Song-Gun, Sung-Keun Rhee, Chi-Yong Ahn, So-Ra Ko, Gang-Guk Choi, Jin-Woo Bae, Yong-Ha Park, and Hee-Mock Oh. "Determination of Cyanobacterial Diversity during Algal Blooms in Daechung Reservoir, Korea, on the Basis of cpcBA Intergenic Spacer Region Analysis." Applied and Environmental Microbiology 72, no. 5 (May 2006): 3252–58. http://dx.doi.org/10.1128/aem.72.5.3252-3258.2006.
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ABSTRACT The detection and prevention of cyanobacterial blooms are important issues in water quality management. As such, the diversity and community dynamics of cyanobacteria during cyanobacterial bloom in the Daechung Reservoir, Korea, were studied by analyzing the intergenic spacer (IGS) region between phycocyanin subunit genes cpcB and cpcA (cpcBA IGS). To amplify the cpcBA IGS from environmental samples, new PCR primers that could cover a wider range of cyanobacteria than previously known primers were designed. In the samples taken around the bloom peak (2 September 2003), seven groups of cpcBA IGS sequences were detected, and none of the amplified cpcBA IGSs was closely related to the cpcBA IGS from chloroplasts. Apart from the Microcystis-, Aphanizomenon (Anabaena)-, Pseudanabaena-, and Planktothrix (Oscillatoria)-like groups, the three other groups of cpcBA IGS sequences were only distantly related to previously reported sequences (<85% similarity to their closest relatives). The most prominent changes during the bloom were the gradual decrease and eventual disappearance of the Aphanizomenon (Anabaena)-like group before the bloom peak and the gradual increase and sudden disappearance of Planktothrix (Oscillatoria)-like groups right after the bloom peak. The community succession profile obtained based on the cpcBA IGS analysis was also supported by a PCR-denaturing gradient gel electrophoresis analysis of the 16S rRNA genes.
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Wilson, Kim M., Mark A. Schembri, Peter D. Baker, and Christopher P. Saint. "Molecular Characterization of the Toxic Cyanobacterium Cylindrospermopsis raciborskii and Design of a Species-Specific PCR." Applied and Environmental Microbiology 66, no. 1 (January 1, 2000): 332–38. http://dx.doi.org/10.1128/aem.66.1.332-338.2000.
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ABSTRACT Cylindrospermopsis raciborskii is a toxic-bloom-forming cyanobacterium that is commonly found in tropical to subtropical climatic regions worldwide, but it is also recognized as a common component of cyanobacterial communities in temperate climates. Genetic profiles of C. raciborskii were examined in 19 cultured isolates originating from geographically diverse regions of Australia and represented by two distinct morphotypes. A 609-bp region of rpoC1, a DNA-dependent RNA polymerase gene, was amplified by PCR from these isolates with cyanobacterium-specific primers. Sequence analysis revealed that all isolates belonged to the same species, including morphotypes with straight or coiled trichomes. Additional rpoC1 gene sequences obtained for a range of cyanobacteria highlighted clustering of C. raciborskii with other heterocyst-producing cyanobacteria (orders Nostocales andStigonematales). In contrast, randomly amplified polymorphic DNA and short tandemly repeated repetitive sequence profiles revealed a greater level of genetic heterogeneity amongC. raciborskii isolates than did rpoC1 gene analysis, and unique band profiles were also found among each of the cyanobacterial genera examined. A PCR test targeting a region of therpoC1 gene unique to C. raciborskii was developed for the specific identification of C. raciborskiifrom both purified genomic DNA and environmental samples. The PCR was evaluated with a number of cyanobacterial isolates, but a PCR-positive result was only achieved with C. raciborskii. This method provides an accurate alternative to traditional morphological identification of C. raciborskii.
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Bowling, L. "Occurrence and possible causes of a severe cyanobacterial bloom in Lake Cargelligo, New South Wales." Marine and Freshwater Research 45, no. 5 (1994): 737. http://dx.doi.org/10.1071/mf9940737.
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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.
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Zhao, C. S., X. Pan, S. T. Yang, X. L. Wang, X. J. Liu, Y. Sun, Y. Yang, and T. L. Pan. "Drivers of cyanobacterial blooms in lakes and reservoirs in Jinan City, China." Marine and Freshwater Research 71, no. 5 (2020): 626. http://dx.doi.org/10.1071/mf18376.
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Cyanobacterial blooms are a serious issue and frequently occur in lakes and reservoirs. Understanding how topography and human activities affect cyanobacterial dominance and blooms can greatly enhance the success of restoration projects to reduce blooms. Therefore, in this study the dominant species of cyanobacteria were determined by calculating the break point of the cumulative dominance curve for multiple sites in Jinan, China. In addition, the key drivers affecting the dominant cyanobacteria species were identified by canonical correspondence analysis and correlations between topography, human activities and the key drivers of the dominant cyanobacteria were investigated using random forests analysis. Merismopedia glauca, Merismopedia tenuissima, Microcystis aeruginosa, Oscillatoria tenuis, Phormidium tenus and Raphidiopsis sinensia were determined to be the dominant species. The key drivers of cyanobacterial bloom development were total phosphorus (TP), ammonium nitrogen (NH3-N), water temperature and total hardness. Topography and human activities were highly correlated with the key driving factors. The higher the altitude, the greater the effect of water temperature on the cyanobacteria community. In the area where sewage irrigation was present and a large amount of chemical fertiliser was used, total hardness had a greater effect on the cyanobacteria community. In areas where the population was more concentrated, TP and NH3-N had greater effects on the cyanobacteria community.
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Lee, T. J., K. Nakano, and M. Matsumura. "A novel strategy for cyanobacterial bloom control by ultrasonic irradiation." Water Science and Technology 46, no. 6-7 (September 1, 2002): 207–15. http://dx.doi.org/10.2166/wst.2002.0681.
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The application of ultrasonic irradiation to control cyanobacterial blooms was evaluated in actual eutrophic lake water. Ten prototype units of the Ultrasonic Irradiation System (USIS) were installed in the 32 ha Lake Senba, and the water and sediment quality were monitored for 2 years. By incorporating the ultrasonication process with the on-going strategy, particularly flushing with induction water, cyanobacterial blooms can be controlled effectively. In addition, a significant improvement in the conditions of the lake in terms of chlorophyll-a, COD and T-P was attained. Moreover, the feasibility of ultrasonic irradiation and bacterial assisted control of cyanobacterial blooms was also evaluated in laboratory conditions. The destruction of gas vacuoles brought about by ultrasonic irradiation promoted close contact between cyanobacteria and their lysing Myxobacter leading to immediate and accelerated destruction of the cells.
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Celikkol, Sukriye, Nathalie Fortin, Nicolas Tromas, Herinandrianina Andriananjamanantsoa, and Charles W. Greer. "Bioavailable Nutrients (N and P) and Precipitation Patterns Drive Cyanobacterial Blooms in Missisquoi Bay, Lake Champlain." Microorganisms 9, no. 10 (October 4, 2021): 2097. http://dx.doi.org/10.3390/microorganisms9102097.
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Anthropogenic activities release large amounts of nitrogen (N) and phosphorus (P) nutrients into the environment. Sources of nutrients include surface and sub-surface runoffs from agricultural practices with the application of chemical fertilizers and manure as well as combined sewer overflows (CSOs). Nutrient runoffs contribute to the eutrophication of aquatic ecosystems and enhance the growth of cyanobacteria. Precipitation is an important driving force behind the runoff of nutrients from agricultural fields into surrounding water bodies. To understand the dynamics between nutrient input, precipitation and cyanobacterial growth in Missisquoi Bay, Lake Champlain (Quebec), one location in Pike River (a major tributary into the bay) and four locations in Missisquoi Bay were monitored from April to November in 2017 and 2018. Biweekly water samples were analyzed using chemical methods and high-throughput sequencing of 16S rRNA gene amplicons. High concentrations of N and P were typically measured in April and May. Three major spikes in nutrient concentrations were observed in early and mid-summer as well as early fall, all of which were associated with intense cumulative precipitation events of 40 to 100 mm within 7 days prior to sampling. Despite the high concentrations of nutrients in the spring and early summer, the cyanobacterial blooms appeared in mid to late summer as the water temperature increased. Dolichospermum sp. was the major bloom-forming cyanobacterium during both summers. A second intense bloom event of Microcystis was also observed in the fall (October and November) for both years. Variation in the cyanobacteria population was strongly associated with inorganic and readily available fractions of N and P such as nitrites and nitrates (NOx), ammonia (NH3) and dissolved organic phosphorus (DOP). During blooms, total Kjeldahl nitrogen (TKN) and total particulate phosphorus (TPP) fractions had a substantial influence on total nitrogen (TN) and total phosphorus (TP) concentrations, respectively. The abundance of bacteria involved in the metabolism of nitrogen compared to that of phosphorus revealed the importance of nitrogen on overall microbial dynamics as well as CB formation in the bay. Our findings emphasize the combined influence of precipitation events, temperature and several bioavailable fractions of nitrogen and phosphorus on cyanobacterial bloom episodes.
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Li, Ji, Kevin Sellner, Allen Place, Jeffrey Cornwell, and Yonghui Gao. "Mitigation of CyanoHABs Using Phoslock® to Reduce Water Column Phosphorus and Nutrient Release from Sediment." International Journal of Environmental Research and Public Health 18, no. 24 (December 18, 2021): 13360. http://dx.doi.org/10.3390/ijerph182413360.
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Cyanobacterial blooms can be stimulated by excessive phosphorus (P) input, especially when diazotrophs are the dominant species. A series of mesocosm experiments were conducted in a lake dominated by a cyanobacteria bloom to study the effects of Phoslock®, a phosphorus adsorbent. The results showed that the addition of Phoslock® lowered the soluble reactive phosphate (SRP) concentrations in water due to efficient adsorption and mitigated the blooms. Once settled on the sediments, Phoslock® serves as a barrier to reduce P diffusion from sediments into the overlying waters. In short-term (1 day) incubation experiments, Phoslock® diminished or reversed SRP effluxes from bottom sediments. At the same time, the upward movement of the oxic–anoxic interface through the sediment column slightly enhanced NH4+ release and depressed N2 release, suggesting the inhibition of nitrification and denitrification. In a long-term (28 days) experiment, Phoslock® hindered the P release, reduced the cyanobacterial abundance, and alleviated the bloom-driven enhancements in the pH and oxygen. These results suggest that, through suppression of internal nutrient effluxes, Phoslock® can be used as an effective control technology to reduce cyanobacteria blooms common to many freshwater systems.
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Neilan, BA, PR Hawkins, PT Cox, and AE Goodman. "Towards a molecular taxonomy for the bloom-forming cyanobacteria." Marine and Freshwater Research 45, no. 5 (1994): 869. http://dx.doi.org/10.1071/mf9940869.
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Regions of the 16s subunit of the ribosomal RNA gene of the bloom-associated cyanobacterial genera Microcystis and Anabaena have been sequenced and found to provide strain-specific sequence information. Comparisons of the DNA sequence of these cyanobacteria indicated that the strains examined are related and that probes diagnostic for bloom-forming and toxigenic strains in water samples can be designed.
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Oliver, Sofia Lizarralde, Priscilla Venâncio Ikefuti, and Helena Ribeiro. "Cyanobacteria bloom variations and atmospheric variables, an environmental health contribution." Ambiente e Agua - An Interdisciplinary Journal of Applied Science 15, no. 4 (July 13, 2020): 1. http://dx.doi.org/10.4136/ambi-agua.2523.
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Urbanization in river basins contributes to the anthropogenic eutrophication of their water bodies, leading to the proliferation of toxic algae such as cyanobacteria. There is a characteristic pattern of seasonality in algal blooms and cyanobacterial communities, although these algae may be present or even dominant for most of the year, causing practical problems associated with high cyanobacterial biomass and potential health threats. The increased concentration of toxins originating from these algae, cyanotoxins, in water-supply reservoirs puts the population at serious risk, since they are not removed by conventional treatment and filtration. This study analyzed possible associations between climate elements and cyanobacteria biomass in the Guarapiranga dam reservoir, located in the metropolitan region of São Paulo, Brazil. Meteorological variables were studied exclusively in relation to the cyanobacteria biomass, in order to perceive the influence of weather and climate in this complex system and to provide data for modeling future climate change scenarios. For this purpose, cyanobacteria count data were used for the period from 2010 to 2016, grouped by month, in addition to the atmospheric variables. The strongest correlation with the blooms was with Irradiation and Total Rainfall, explaining 30% of cases of the occurrence of cyanobacteria proliferation at the point of collection GU 101. Despite the notable influence of climatic seasonality on the algae blooms, this difference varies and is not homogeneous, depending on the location and the species studied.
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Metcalf, James S., Sandra Anne Banack, James T. Powell, Fiona J. M. Tymm, Susan J. Murch, Larry E. Brand, and Paul Alan Cox. "Public health responses to toxic cyanobacterial blooms: perspectives from the 2016 Florida event." Water Policy 20, no. 5 (July 18, 2018): 919–32. http://dx.doi.org/10.2166/wp.2018.012.
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Abstract In June 2016, massive cyanobacterial blooms occurred in the St. Lucie River in Florida, caused by nutrient and cyanobacterial-laden water releases from Lake Okeechobee. We independently collected and analyzed bloom material for cyanotoxin diversity and concentrations. The concentrations of microcystins, potent hepatotoxins, present in the bloom material greatly exceeded World Health Organization Guideline Values for drinking and recreational water. We also detected the neurotoxins anatoxin-a(S) and β-N-methylamino-L-alanine (BMAA). The Florida State Governor declared a state of emergency, but many affected aquatic recreational areas in St. Lucie County remained open during the bloom event without adequate hazard notification to citizens. During the bloom event, issues with preparedness, communication, sampling, analysis, closures and contingencies were observed. We suggest better ways that cyanobacterial bloom events can be predicted, managed, and mitigated in the future throughout the world. As similar problems with cyanobacterial bloom frequency and occurrence present worldwide, understanding governmental responses to the 2016 Florida incident can help in the development of effective mitigation and management strategies for future bloom events.
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Solis, Michał, Barbara Pawlik-Skowrońska, Małgorzata Adamczuk, and Renata Kalinowska. "Dynamics of small-sized Cladocera and their algal diet in lake with toxic cyanobacterial water blooms." Annales de Limnologie - International Journal of Limnology 54 (2018): 6. http://dx.doi.org/10.1051/limn/2018001.
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Species composition and quantitative structure of small-sized Cladocera community and their algal diet before, during and after cyanobacterial blooms were studied in highly eutrophic lake. The objective of the study was to investigate, how the mass development of toxin-producing cyanobacteria affect the abundances of small-sized Cladocera and their preferences within consumed algal cells. Cyanobacterial blooms were predominantly constituted by microcystin-producing genera Planktothrix, Dolichospermum, Microcystis. The concentration of intracellular microcystins in lake water ranged 0.0–23.61 μg dm−3. Bosmina longirostris, B. coregonii, Diaphanosoma brachyurum and Daphnia cucullata were dominant in Cladocera community. The highest abundances of B. longirostris occurred in periods without cyanobacterial blooms and B. coregonii during blooms and after them. The maximum abundances of D. cucullata were observed before and after the cyanobacterial blooms, while the abundance of D. brachyurum was the highest at the beginning of blooms. Small Bacillariophyceae, small Chlorophyceae and Cryptophyceae were the most abundant among identified algal cells detected in digestive tracts of the Cladocera dominants. Tracts of D. cucullata, B. longirostris and B. coregonii contained the highest number of Bacillariophyceae always before blooms. During cyanobacterial blooms, cells of small Chlorophyceae predominated in tracts of D. cucullata. After bloom, cells of Cryptomonas spp. were mainly consumed both by D. cucullata and by B. coregonii. Fragments of Dolichospermum spp., besides Bacillariophyceae and Cryptomonas spp. cells, were occasionally found in tracts of D. brachyurum. Our study indicated that blooms constituted by toxin-producing cyanobacteria may influence quantitative and qualitative structure of the small-sized Cladocera community.
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Kopp, Radovan, Miroslava Palíková, Stanislav Navrátil, Zdenek Kubíček, Andrea Ziková, and Jan Mareš. "Modulation of Biochemical and Haematological Indices of Silver Carp (Hypophthalmichthys molitrix Val.) Exposed to Toxic Cyanobacterial Water Bloom." Acta Veterinaria Brno 79, no. 1 (2010): 135–46. http://dx.doi.org/10.2754/avb201079010135.
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The aim of this study was to evaluate the influence of toxic cyanobacterial water bloom on the blood indices of two-year-old silver carp (Hypophthalmichthys molitrixVal.). Experimental fish (336 ± 32 mm length, 365 ± 112 g weight) were exposed to a natural population of cyanobacterial water bloom (mainlyMicrocystis aeruginosaandM. ichthyoblabe) that contained microcystins (total concentration 133–284 μg g-1(DW), concentration in water 2.8–7.4 μg l-1). Haematological indices showed marked changes in fish exposed to the cyanobacterial population compared to the control group. Statistical evaluation of the influence of cyanobacterial water bloom on biochemical and haematological indices of silver carp showed a distinct decrease of albumin, alkaline phosphatase, cholesterol, glucose, total protein, creatinine, lactate, lactate dehydrogenase, phosphorus, iron, cholinesterase, haemoglobin, haematocrit, erythrocyte and leukocyte compared to the control. Values of alanine aminotransferase were significantly increased compared to the control. After exposure to the cyanobacterial water bloom, the silver carp were kept in pure water for monitoring the persistence of biochemical and haematological indices. Influence of the cyanobacterial population on values of albumin, alkaline phosphatase, cholesterol, total protein, glucose, creatinine, phosphorus, iron, cholinesterase, erythrocyte and haematocrit persisted up to 28 days after the end of exposure. Duration of exposure, toxicity and density of cyanobacterial water bloom had an important impact on individual biochemical and haematological indices.
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Jalili, Farhad, Saber Moradinejad, Arash Zamyadi, Sarah Dorner, Sébastien Sauvé, and Michèle Prévost. "Evidence-Based Framework to Manage Cyanobacteria and Cyanotoxins in Water and Sludge from Drinking Water Treatment Plants." Toxins 14, no. 6 (June 15, 2022): 410. http://dx.doi.org/10.3390/toxins14060410.
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Freshwater bodies and, consequently, drinking water treatment plants (DWTPs) sources are increasingly facing toxic cyanobacterial blooms. Even though conventional treatment processes including coagulation, flocculation, sedimentation, and filtration can control cyanobacteria and cell-bound cyanotoxins, these processes may encounter challenges such as inefficient removal of dissolved metabolites and cyanobacterial cell breakthrough. Furthermore, conventional treatment processes may lead to the accumulation of cyanobacteria cells and cyanotoxins in sludge. Pre-oxidation can enhance coagulation efficiency as it provides the first barrier against cyanobacteria and cyanotoxins and it decreases cell accumulation in DWTP sludge. This critical review aims to: (i) evaluate the state of the science of cyanobacteria and cyanotoxin management throughout DWTPs, as well as their associated sludge, and (ii) develop a decision framework to manage cyanobacteria and cyanotoxins in DWTPs and sludge. The review identified that lab-cultured-based pre-oxidation studies may not represent the real bloom pre-oxidation efficacy. Moreover, the application of a common exposure unit CT (residual concentration × contact time) provides a proper understanding of cyanobacteria pre-oxidation efficiency. Recently, reported challenges on cyanobacterial survival and growth in sludge alongside the cell lysis and cyanotoxin release raised health and technical concerns with regards to sludge storage and sludge supernatant recycling to the head of DWTPs. According to the review, oxidation has not been identified as a feasible option to handle cyanobacterial-laden sludge due to low cell and cyanotoxin removal efficacy. Based on the reviewed literature, a decision framework is proposed to manage cyanobacteria and cyanotoxins and their associated sludge in DWTPs.
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Pawelec, Anna J., Mariusz R. Sapota, and Justyna Kobos. "The effect of algal blooms on fish in their inshore nursery grounds in the Gulf of Gdańsk." Journal of the Marine Biological Association of the United Kingdom 98, no. 1 (September 12, 2017): 97–104. http://dx.doi.org/10.1017/s0025315417001606.
Full textAbstract:
Studies of cyanobacterial bloom dynamics show that the highest biomass accumulation of Nodularia spumigena is observed in the shallowest area of the Gulf of Gdańsk in summer. In the same region and time, the highest fish abundance is observed. Mostly young individuals of gobies, small sandeel, flounder, three-spine stickleback and young herring occur. In this work we compare how toxic blooms of cyanobacteria influence the number and structure of fish communities in a coastal zone. The results obtained in our study were rather unexpected. More fish species were caught and the biomass of fish was higher during a bloom than in a month following the sampling (no bloom).
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Moustaka-Gouni, M., U. Sommer, M. Katsiapi, and E. Vardaka. "Monitoring of cyanobacteria for water quality: doing the necessary right or wrong?" Marine and Freshwater Research 71, no. 5 (2020): 717. http://dx.doi.org/10.1071/mf18381.
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Cyanobacteria are an essential biological component of phytoplankton water quality assessment. However, there are some problems associated with the widely used everyday practices of sampling, estimation and use of cyanobacteria when calculating phytoplankton indices assessing water quality. Many indices were developed during the implementation of the Water Framework Directive, considered the most innovative European environmental legislation. Most indices include cyanobacteria as a composition or bloom metric. Problems with the indices concern the exclusion of most chroococcalean taxa from cyanobacterial biovolume estimations in lakes and reservoirs of the Mediterranean region, treatment of the mucilage of colonial chroococcalean taxa in biovolume estimations and overlooking of deep-water cyanobacterial blooms due to sampling depth. These problems may lead to a biased view of water quality. In this paper we argue in favour of including all cyanobacteria taxa and their mucilage in biovolume estimations and considering a sampling depth that covers deep-water maxima, such as those formed by Planktothrix rubescens or colonial chroococcalean taxa.
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Gu, Peng, Qi Li, Hao Zhang, Xin Luo, Weizhen Zhang, Zheng Zheng, and Xingzhang Luo. "Effects of Cyanobacteria on Phosphorus Cycling and Other Aquatic Organisms in Simulated Eutrophic Ecosystems." Water 12, no. 8 (August 12, 2020): 2265. http://dx.doi.org/10.3390/w12082265.
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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.
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Mohan, Renju, Twinkle Sathish, and Kunnatholickal Balakrishnan Padmakumar. "Occurrence of potentially toxic cyanobacteria Microcystis aeruginosa in aquatic ecosystems of central Kerala (south India)." Annales de Limnologie - International Journal of Limnology 56 (2020): 18. http://dx.doi.org/10.1051/limn/2020015.
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Microcystis aeruginosa is a potentially toxic bloom-forming freshwater cyanobacterium, usually found in eutrophic water bodies worldwide. The present study reports the occurrence of Microcystis aeruginosa and its bloom in freshwater ponds along central Kerala (south India). Monitoring of cyanobacterial blooms was conducted from May 2019 to February 2020 along the aquatic ecosystems of central Kerala and the M. aeruginosa blooms were recorded from two freshwater ponds of Kochi. Massive blooms of M. aeruginosa was observed during the period prior to summer monsoon (May) with an abundance of 1.17 × 106 cells L‑1 (Station 1) and during early summer (February) latter being more thick scum (2 × 108 cells L‑1) with high chlorophyll a. Dense aggregates of M. aeruginosa scums were more prevalent during the periods characterised by higher Surface Water Temperature (SWT). The nutrient characteristic pattern of the study area showed the abundance of M. aeruginosa correlated very well with higher dissolved nitrate (96.7 μmol L‑1) and phosphate (19.88 μmol L‑1) concentrations. Thus in the stable freshwater ponds with higher SWT and nutrients were the major factors influencing the growth and abundance of the cyanobacteria M. aeruginosa. Toxicological studies conducted revealed that the Microcystis bloom was hepatotoxic, inflicting fish mortality.
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Palíková, Miroslava, Radovan Kopp, Jan Mareš, Stanislav Navrátil, Zdenek Kubíček, Lubomír Chmelař, Hana Banďouchová, and Jiří Pikula. "Selected Haematological and Biochemical Indices of Nile Tilapia (Oreochromis niloticus) Reared in the Environment with Cyanobacterial Water Bloom." Acta Veterinaria Brno 79, no. 9 (2010): S63—S71. http://dx.doi.org/10.2754/avb201079s9s063.
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The aim of this study was to evaluate the influence of toxic cyanobacterial water blooms on blood indices in the Nile tilapia (Oreochromis niloticus). Experimental fish were exposed to natural cyanobacterial water blooms (consisting mainly of Microcystis aeruginosa and M. ichthyoblabe) which contained microcystins (total concentration 1187 - 1211 μg g-1 of dry weight and 17.4 - 25.4 μg l-1 of water) for 28 days without additional feeding. Control groups of fish were kept in another pond without apparent cyanobacterial bloom formation. Experimental and control rearing ponds had the same water source. After exposure, fish were placed in dechlorinated potable water for the same period. Statistical evaluation of the influence of cyanobacterial water bloom on biochemical indices of experimental fish showed a distinct increase of alkaline phosphatase (p ⪬ 0.05), total bilirubin (p ⪬ 0.001), creatinine (p ⪬ 0.01), lactate (p ⪬ 0.01) and urea (p ⪬ 0.01) when compared to controls. After transfer to the dechlorinated potable water the experimental group showed significantly lower values of phosphorus (p ⪬ 0.001), urea (p ⪬ 0.01) and cholinesterase (p ⪬ 0.05) and higher values of lactate (p ⪬ 0.05) and iron (p ⪬ 0.05) compared to controls. It may be concluded that the exposure of the Nile tilapia to the environment containing cyanobacterial water bloom influenced only some biochemical indices. However, this modulation is to a much lower degree compared to the common carp and silver carp.
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Al-Tebrineh, Jamal, Troco Kaan Mihali, Francesco Pomati, and Brett A. Neilan. "Detection of Saxitoxin-Producing Cyanobacteria and Anabaena circinalis in Environmental Water Blooms by Quantitative PCR." Applied and Environmental Microbiology 76, no. 23 (October 8, 2010): 7836–42. http://dx.doi.org/10.1128/aem.00174-10.
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ABSTRACT Saxitoxins (STXs) are carbamate alkaloid neurotoxins produced by marine “red tide” dinoflagellates and several species of freshwater filamentous cyanobacteria, including Anabaena circinalis, Aphanizomenon spp., Lyngbya wollei, and Cylindrospermopsis raciborskii. A specific quantitative PCR (qPCR) method based on SYBR green chemistry was developed to quantify saxitoxin-producing Anabaena circinalis cyanobacteria, which are major bloom-forming freshwater cyanobacteria. The aim of this study was to infer the potential toxigenicity of samples by determining the copy number of a unique and unusual polyketide synthase (PKS) sequence (sxtA) in the STX biosynthesis gene cluster identified in cyanobacteria. Our qPCR approach was applied to water samples collected from different Australian lakes, dams, and rivers. The STX concentration and cyanobacterial cell density of these blooms were also determined by high-pressure liquid chromatography (HPLC) and microscopic cell counting, respectively. STX concentrations correlated positively with STX gene copy numbers, indicating that the latter can be used as a measure of potential toxigenicity in Anabaena circinalis and possibly other cyanobacterial blooms. The qPCR method targeting STX genes can also be employed for both monitoring and ecophysiological studies of toxic Anabaena circinalis blooms and potentially several other STX-producing cyanobacteria.
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Pham, Thanh Luu, Tran Thi Hoang Yen, Tran Thanh Thai, and Ngo Xuan Quang. "Using quantitative real-time polymerase chain reaction (qRT-PCR) for detection microcystin producing cyanobacteria." Science and Technology Development Journal 24, no. 2 (May 12, 2021): first. http://dx.doi.org/10.32508/stdj.v24i2.2523.
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Introduction: Cyanobacterial blooms (CBs) have become a growing concern worldwide. In the natural environment, potentially toxic (can produce toxins) and non-toxic (can not produce toxins) colonies often co-exist within a bloom.
Methods: The present study aimed to quantify toxic and non-toxic cells of cyanobacteria in the Tri An Reservoir (TAR) using a quantitative real-time polymerase chain reaction (qRT-PCR).
Results: Results showed that the Microcystis genus dominated the cyanobacterial communities in the TAR. Microcystis was also the primary microcystins (MC) producing cyanobacteria in the water. Total cyanobacteria and Microcystis cells ranged from 152103 to 27106 copy/L and from 105103 to 19106 copy/L, respectively. The cell number of potentially MC-producing cyanobacteria (corresponding to the Microcystis mcyD gene) varied from 27103 to 13106 copy/L. MC concentrations often present in raw water with a concentration of up to 4.8 mg/L. Our results showed that the MC concentration in raw water was positively correlated with the mcyD copy number, suggesting that Microcystis spp. are the main toxin producers in the TAR's surface water.
Conclusion: Our study suggested that qRT-PCR techniques and traditional count are comparable and could be used to quantify cyanobacteria. In addition, the qRT-PCR techniques can determine the toxic cyanobacterial cells and could be used as a tool for early monitoring of toxic cyanobacteria in lakes and reservoirs.
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Li, Jiajin, Chujun Zou, Ran Liao, Liang Peng, Hongjian Wang, Zhiming Guo, and Hui Ma. "Characterization of Intracellular Structure Changes of Microcystis under Sonication Treatment by Polarized Light Scattering." Biosensors 11, no. 8 (August 17, 2021): 279. http://dx.doi.org/10.3390/bios11080279.
Full textAbstract:
Cyanobacterial bloom is one of the most urgent global environmental issues, which eventually could threaten human health and safety. Sonication treatment (ST) is a potential effective method to control cyanobacteria blooms in the field. Currently, the bottleneck of extensive application of ST is the difficulty to estimate the ST effect on the cyanobacterial cells and then determine suitable ST times in the field. In this study, cyanobacterial Microcystis samples sonicated at different times were first measured by a spectrophotometer to calculate the removal efficiency of Microcystis cells. Additionally, they were observed by TEM to reveal the intracellular structure changes of the cells. Then the samples were measured by an experimental setup based on polarized light scattering to measure the polarization parameters. Experimental results indicated that the polarization parameters can effectively characterize the intracellular structural changes of Microcystis cells with different ST times, which is quite consistent with the results for removal efficiency and TEM images. Further, the optimal ST time can be inferred by the polarization parameters. These results demonstrate that polarized light scattering can be a potentially powerful tool to explore suitable times for sonication treatment of cyanobacteria blooms.
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Koreivienė, Judita, Olga Belous, and Jūratė Kasperovičienė. "Variations of microcystins in freshwater ecosystems." Botanica Lithuanica 19, no. 2 (December 1, 2013): 139–48. http://dx.doi.org/10.2478/botlit-2013-0017.
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Abstract Koreivienė J., Belous O., Kasperovičienė J., 2012: Variations of microcystins in freshwater ecosystems [Mikrocystinai gėlavandenėse ekosistemose]. - Bot. Lith., 19(2): 139-148 Increased frequency, severity of harmful algae blooms and their extent worldwide have become a global challenge due to the production of toxins that are released to the water. Cyanotoxins are detected in 25-75% of blooms. Hazardous hepatotoxin-microcystin potential producers, spatial and temporal variations of toxins as well as their variations depending on environmental variables are discussed in this overview. The most common species among microcystin producers belong to the genera Dolichospermum and Microcystis. Variations of the amount of microcystins detected through the bloom are associated with the dominant cyanobacteria species or its genotype. The abundance of toxic cyanobacteria genotype and cyanotoxin values increase with the rise of water temperature and nutrient concentrations in the freshwaters. On the seasonal basis, cell-bound microcystin concentrations increase with bloom development, whereas extracellular cyanotoxin values rise with the senescing of bloom after cyanobacterial cell lysis.