What makes a cyanobacterial bloom disappear? A review of the abiotic and biotic cyanobacterial bloom loss factors

Harmful Algae, Journal Year: 2024, Volume and Issue: 133, P. 102599 - 102599

Published: Feb. 9, 2024

Cyanobacterial blooms present substantial challenges to managers and threaten ecological public health. Although the majority of cyanobacterial bloom research management focuses on factors that control initiation, duration, toxicity, geographical extent, relatively little role loss processes in how these are regulated. Here, we define a process terms population dynamics as any removes cells from population, thereby decelerating or reducing development extent blooms. We review abiotic (e.g., hydraulic flushing oxidative stress/UV light) biotic allelopathic compounds, infections, grazing, resting cells/programmed cell death) known govern loss. found dominant depend several system specific including genera-specific traits, situ physicochemical conditions, microbial, phytoplankton, consumer community composition. also address context discuss perspectives predicting changing climate may directly indirectly affect A deeper understanding their underlying mechanisms help mitigate negative consequences improve current strategies.

Language: Английский

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Fate of a toxic Microcystis aeruginosa bloom introduced into a subtropical estuary from a flow-managed canal and management implications

Journal of Environmental Management, Journal Year: 2025, Volume and Issue: 375, P. 124362 - 124362

Published: Feb. 1, 2025

The Caloosahatchee Estuary in southwest Florida, USA, is regularly subject to the introduction of toxic Microcystis aeruginosa blooms, often originating from eutrophic Lake Okeechobee via C-43 Canal. focus this study was determine responses one these introduced blooms progressively elevated salinity levels as bloom water mass moved through estuary. In upper estuary, salinities were freshwater, and surface large colonies M. observed, along with peak microcystin toxin concentrations up 107 μg L-1, all particulate fraction. mid-estuary, increased 2-6, again 259 however, significant extracellular also observed (i.e., 17.8 L-1), suggesting a level osmotic stress on aeruginosa. lower ranged 6 25 very few viable but 0.5 L-1) present throughout column. It noteworthy that average total column + extracellular) remained constant movement during its transit revealing negligible rate degradation ten-day transit. results provide insights into changes distribution gradient, which has implications for management risks ecosystem human health, how may be affected by releases three control structures Discharge rates play major roles Canal-Caloosahatchee ecosystem. potential discharge regulation are discussed perspectives allochthonous autochthonous origin.

Language: Английский

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Climate change and the aquatic continuum: A cyanobacterial comeback story

Environmental Microbiology Reports, Journal Year: 2022, Volume and Issue: 15(1), P. 3 - 12

Published: Sept. 12, 2022

Billions of years ago, the Earth's waters were dominated by cyanobacteria. These microbes amassed to such formidable numbers, they ushered in a new era-starting with Great Oxidation Event-fuelled oxygenic photosynthesis. Throughout following eon, cyanobacteria ceded portions their global aerobic power photoautotrophs rise eukaryotes (i.e. algae and higher plants), which co-existed aquatic ecosystems. Yet while cyanobacteria's ecological success story is one most notorious within our planet's biogeochemical history, scientists this day still seek unlock secrets triumph. Now, Anthropocene has era fuelled excessive nutrient inputs greenhouse gas emissions, are again reshaping biomes. In response, we experiencing an increase cyanobacterial bloom distribution, duration, frequency, leading unbalanced, many instances degraded, A critical component resurgence freshwater-marine continuum: serves transport blooms, toxins produce, on premise that "water flows downhill". Here, identify drivers contributing comeback discuss future implications context environmental human health along continuum. This Minireview addresses overlooked problem freshwater marine continuum effects nutrients toxic blooms moving these waters. Marine research have historically been conducted isolation independently another. Yet, approach fails account for interchangeable transit biology through between systems, phenomenon becoming major around globe. highlights what know challenges lie ahead.

Language: Английский

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Harmful algal bloom aerosols and human health

EBioMedicine, Journal Year: 2023, Volume and Issue: 93, P. 104604 - 104604

Published: May 8, 2023

Harmful algal blooms (HABs) are increasing across many locations globally. Toxins from HABs can be incorporated into aerosols and transported inland, where subsequent exposure inhalation induce adverse health effects. However, the relationship between HAB outcomes remains unclear despite potential for population-level exposures. In this review, we synthesized current state of knowledge identified evidence gaps in human health. Aerosols Karenia brevis, Ostreopsis sp., cyanobacteria were linked with respiratory outcomes. most works did not directly measure aerosol or toxin concentrations instead relied on proxy metrics exposure, such as cell nearby waterbodies. Furthermore, number studies epidemiological designs was limited. Significant uncertainties remain regarding effects other species; threshold dose dose-response relationship; concurrent exposures to mixtures toxins sources, microplastics metals; impact long-term exposures; disparities associated potentially vulnerable subpopulations. Additional employing multifaceted assessment methods leveraging large databases could address improve our understanding public burden HABs.

Language: Английский

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A tale of two blooms: do ecological paradigms for algal bloom success and succession require revisiting?

Journal of Great Lakes Research, Journal Year: 2024, Volume and Issue: 50(3), P. 102336 - 102336

Published: April 1, 2024

Lake Erie algal bloom discussions have historically focused on cyanobacteria, with foundational "blooms like it hot" and "high nutrient" paradigms considered as primary drivers behind cyanobacterial success. Yet, recent surveys rediscovered winter-spring diatom blooms, introducing another key player in the eutrophication story which has been overlooked. These blooms (summer vs. winter) treated solitary events separated by spatial temporal gradients. However, new evidence suggests they may not be so isolated, linked a manner that manifests an cycle. Equally notable are emerging reports of cold and/or oligotrophic freshwaters, interpreted some shifts classical paradigms. led many to ask "what is bloom?". Furthermore, questioning classic caused others wonder if we overlooking additional factors constrain In light data ideas, revisited concepts within context derived five take-aways: 1) Additional bloom-formers (diatoms) need included discussions, 2) The term "bloom" must reinforced clear definition quantitative metrics for each event, 3) Algal should studied solitarily, 4) Shifts physiochemical conditions serve alternative interpretation potential ecological paradigms, 5) success succession (i.e., pH light) require consideration.

Language: Английский

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Aerobic anoxygenic phototrophs play important roles in nutrient cycling within cyanobacterial Microcystis bloom microbiomes

Microbiome, Journal Year: 2024, Volume and Issue: 12(1)

Published: May 13, 2024

Abstract Background During the bloom season, colonial cyanobacterium Microcystis forms complex aggregates which include a diverse microbiome within an exopolymer matrix. Early research postulated simple mutualism existing with bacteria benefitting from rich source of fixed carbon and receiving recycled nutrients. Researchers have since hypothesized that represent community synergistic interacting species, interactome, each unique metabolic capabilities are critical to growth, maintenance, demise blooms. Research has also shown aggregate-associated taxonomically different free-living in surrounding water. Moreover, identified little overlap functional potential between members its microbiome, further supporting interactome concept. However, we still lack verification general interaction know about taxa pathways nutrient metabolite cycling aggregates. Results 7-month study bacterial communities comparing Lake Taihu, China, found aerobic anoxygenic phototrophic (AAP) were significantly more abundant than samples, suggesting possible role for AAP overall aggregate function. We then analyzed gene composition 102 high-quality metagenome-assembled genomes (MAGs) bloom-microbiome 10 lakes spanning four continents, compared 12 complete revealed possessed complementary biochemical could serve C, N, S, P cycling. Mapping published transcripts blooms onto comprehensive non-AAP MAG database (226 MAGs) indicated observed high levels expression genes involved bacteria. Conclusions Our results provide strong corroboration first evidence may play important microbiomes.

Language: Английский

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Occurrence, Distribution and Toxins of Benthic Cyanobacteria in German Lakes

Toxics, Journal Year: 2023, Volume and Issue: 11(8), P. 643 - 643

Published: July 25, 2023

Cyanobacteria are favored by climate change and global warming; however, to date, most research monitoring programs have focused on planktic cyanobacteria. Benthic cyanobacteria blooms also increase pose a risk animal human health; there is limited knowledge of their occurrence, distribution the toxins involved, especially in relation conspecifics. Therefore, we analyzed benthic life forms cyanobacterial communities 34 lakes Germany, including cyanotoxins. Community analyses were based microscopic examination Illumina sequencing 16S rRNA gene. The cyanotoxins carried out using LC-MS/MS ELISA. Observed mats containing consisted mainly Nostocales Oscillatoriales, being present 35% lakes. Anatoxin was abundant cyanotoxin samples, reaching maximum concentrations 45,000 µg/L, whereas microcystin predominate open-water up 18,000 µg/L. Based results, specific at toxic could be identified. Our findings suggest that should receive greater attention, ideally complementing existing sampling with little additional effort.

Language: Английский

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Metabarcoding vs Microscopy: Comparison of Methods To Monitor Phytoplankton Communities

ACS ES&T Water, Journal Year: 2023, Volume and Issue: 3(8), P. 2671 - 2680

Published: July 21, 2023

Phytoplankton are used worldwide to monitor the environmental status of aquatic systems. Long-time series microscopy-analyzed phytoplankton available from many monitoring stations. The microscopy method is, however, time-consuming and has shortcomings. DNA metabarcoding been suggested as an alternative method, but consistency between different methods needs further investigation. We performed a comparative study analyzing micro- nanophytoplankton. For metabarcoding, 25–1000 mL seawater was filtered, extracted, 18S 16S rRNA gene amplicons sequenced. microscopy, based on Utermöhl we evaluated use three metrics: abundance, biovolume, carbon biomass. At genus, species, unidentified taxa levels, generally showed higher taxonomic diversity than already captured at lowest filtration volume tested, 25 mL. Metabarcoding displayed relatively similar distribution patterns group level. results that relative abundances amplicon level best fitted biomass metric. promising for implementing complement in monitoring, especially if databases were improved group-level indices could be applied classify state water bodies.

Language: Английский

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Unveiling the link between Raphidiopsis raciborskii blooms and saxitoxin levels: Evaluating water quality in tropical reservoirs, Brazil

Environmental Pollution, Journal Year: 2024, Volume and Issue: 344, P. 123401 - 123401

Published: Jan. 21, 2024

Language: Английский

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Exploring factors that affect Microcystis abundance in the sacramento san joaquin delta

Harmful Algae, Journal Year: 2024, Volume and Issue: 138, P. 102682 - 102682

Published: June 25, 2024

Cyanobacteria harmful algal blooms (cHABs) are increasing in frequency, intensity and duration estuaries worldwide. In the upper San Francisco Estuary, also known as Sacramento Joaquin Delta (Delta), cHABs have been a topic of concern over past two decades. response, managers urgently working to understand factors that drive identify feasible management options avert ecological human health consequences. We used six year data set explore relationships between flow parameters, temperature, Microcystis biovolume determine potential for managing large scale hydrodynamic conditions address cHABs. looked at relationship low salinity zone see if it could be proxy residence time, because time is positively related cyanobacteria abundance. found not useful area experiences most severe Our finding suggest climatic (i.e., temperature water type) greatest influence on Delta, with higher during years lower temperatures. Further, there interannual differences cannot fully explained by parameters or meaning other included our model may involved. conclude actions increase ineffective reducing desired levels temperatures remain high.

Language: Английский

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