scholarly journals Microbial and chemical dynamics of a toxic dinoflagellate bloom

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9493
Author(s):  
Nastassia V. Patin ◽  
Emily Brown ◽  
Gabriella Chebli ◽  
Claire Garfield ◽  
Julia Kubanek ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Economic Damage ◽  
Sequence Variant ◽  
Toxic Dinoflagellate ◽  
Bloom Formation ◽  
Intracellular Metabolite Pools ◽  
Domain Level ◽  
Dinoflagellate Bloom

Harmful Algal Blooms (HABs) exert considerable ecological and economic damage and are becoming increasingly frequent worldwide. However, the biological factors underlying HABs remain uncertain. Relationships between algae and bacteria may contribute to bloom formation, strength, and duration. We investigated the microbial communities and metabolomes associated with a HAB of the toxic dinoflagellate Karenia brevis off the west coast of Florida in June 2018. Microbial communities and intracellular metabolite pools differed based on both bacterial lifestyle and bloom level, suggesting a complex role for blooms in reshaping microbial processes. Network analysis identified K. brevis as an ecological hub in the planktonic ecosystem, with significant connections to diverse microbial taxa. These included four flavobacteria and one sequence variant unidentified past the domain level, suggesting uncharacterized diversity in phytoplankton-associated microbial communities. Additionally, intracellular metabolomic analyses associated high K. brevis levels with higher levels of aromatic compounds and lipids. These findings reveal water column microbial and chemical characteristics with potentially important implications for understanding HAB onset and duration.

scholarly journals Long-Term Eutrophication and Dynamics of Bloom-Forming Microbial Communities during Summer HAB in Large Arctic Lake

Environments ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 82
Author(s):  
Nikolay Kashulin ◽  
Tatiana Kashulina ◽  
Alexander Bekkelund
Keyword(s):  
Microbial Communities ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Temporal Dynamics ◽  
Arctic Lakes ◽  
Genetic Traits ◽  
Genetic Mechanisms ◽  
Redfield Ratios ◽  
Lake Imandra

Harmful algal blooms (HABs) in arctic lakes are recent phenomena. In our study, we performed a long-term analysis (1990–2017) of the eutrophication of Lake Imandra, a large subarctic lake, and explored the biodiversity of bloom-forming microorganisms of a 2017 summer HAB. We performed a 16Sr rRNA metabarcoding study of microbial communities, analysed the associations between N, P, C, and chlorophyll concentrations in the lake water, and developed models for the prediction of HABs based on total P concentration. We have demonstrated that blooms in Lake Imandra occur outside of optimal Redfield ratios and have a nonlinear association with P concentrations. We found that recent summer HABs in a lake occur as simultaneous blooms of a diatom Aulacoseira sp. and cyanobacteria Dolichospermum sp. We have studied the temporal dynamics of microbial communities during the bloom and performed an analysis of the publicly available Dolichospermum genomes to outline potential genetic mechanisms beneath simultaneous blooming. We found genetic traits requisite for diatom-diazotroph associations, which may lay beneath the simultaneous blooming of Aulacoseira sp. and Dolichospermum sp. in Lake Imandra. Both groups of organisms have the ability to store nutrients and form a dormant stage. All of these factors will ensure the further development of the HABs in Lake Imandra and the dispersal of these bloom-forming species to neighboring lakes.

scholarly journals Machine Learning Classification Algorithms for Predicting Karenia brevis Blooms on the West Florida Shelf

2021 ◽  
Vol 9 (9) ◽  
pp. 999
Author(s):  
Marvin F. Li ◽  
Patricia M. Glibert ◽  
Vyacheslav Lyubchich
Keyword(s):  
Machine Learning ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Large River ◽  
Karenia Brevis ◽  
Machine Learning Algorithms ◽  
Support Vector ◽  
Economic Damage ◽  
The West ◽  
Machine Learning Classification

Harmful algal blooms (HABs), events that kill fish, impact human health in multiple ways, and contaminate water supplies, have increased in frequency, magnitude, and impacts in numerous marine and freshwaters around the world. Blooms of the toxic dinoflagellate Karenia brevis have resulted in thousands of tons of dead fish, deaths to many other marine organisms, numerous respiratory-related hospitalizations, and tens to hundreds of millions of dollars in economic damage along the West Florida coast in recent years. Four types of machine learning algorithms, Support Vector Machine (SVM), Relevance Vector Machine (RVM), Naïve Bayes classifier (NB), and Artificial Neural Network (ANN), were developed and compared in their ability to predict these blooms. Comparing the 21 year monitoring dataset of K. brevis abundance, RVM and NB were found to have better skills in bloom prediction than the other two approaches. The importance of upwelling-favorable northerly winds in increasing K. brevis probability, and of onshore westerly winds in preventing blooms from dispersing offshore, were quantified using RVM, and all models were used to explore the importance of large river flows and the nutrients they supply in regulating blooms. These models provide new tools for management of these devastating algal blooms.

scholarly journals Distribusi dan Kelimpahan Kista Pyrodinium bahamense di Perairan Rawan Marak Alga Berbahaya di Indonesia

2021 ◽  
Vol 6 (1) ◽  
pp. 37
Author(s):  
Arief Rachman ◽  
Mariana D. B. Intan ◽  
Hikmah Thoha ◽  
Oksto Ridho Sianturi ◽  
Estelle Masseret
Keyword(s):  
Coastal Waters ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Risk Level ◽  
Distribution Data ◽  
Toxic Dinoflagellate ◽  
Literature Study ◽  
Potential Source ◽  
Pyrodinium Bahamense ◽  
Negative Impacts

<strong>Distribution and abundance of <em>Pyrodinium bahamense</em> cyst in the harmful algal blooms risk waters in Indonesia. </strong><em>Pyrodinium bahamense</em>as Harmful Algal Blooms (HABs) is one of the rising environmental problems in the coastal areas of Southeast Asia, particularly in Indonesia. Cyst bank formed after the blooms of <em>P. bahamense</em> is a potential source for the future blooming events. Therefore, an effort to describe the distribution and abundance of <em>P. bahamense</em> cyst banks in Indonesian coastal waters is necessary as a part of the mitigation strategy against the negative impacts of those toxic dinoflagellate blooms. This study was done as a desk study, which included a literature study, reanalysed of previous research data, and reanalysed of preserved samples or stored raw samples. Data and samples used in this study were collected and analysed from part of past researches in Lampung Bay, Jakarta Bay, Cirebon coastal waters, and Ambon Bay. This study also included an analysis to determine the <em>P. Bahamense </em>HABs risk level in the studied areas based on the cyst density and distribution data. Results showed a low density of <em>P. bahamense </em>cyst in Lampung Bay and Jakarta Bay, with cyst density &lt;50 cysts.g<sup>-1</sup> wet sediment. In contrast, the bottom sediments of Ambon Bay and Cirebon coastal waters contained high cyst density, which reached &gt;1,000 cysts.g<sup>-1</sup> wet sediment. Based on those data, the <em>P. Bahamense </em>HABs risk in Jakarta Bay and Lampung Bay would be generally much lower compared to Ambon Bay and Cirebon waters. The existence of cyst banks in those coastal waters may indicate  a possibility of future blooms of <em>P. bahamense</em>.

scholarly journals Zooming in on dynamics of marine microbial communities in the phycosphere of Akashiwo sanguinea (Dinophyta) blooms

2020 ◽  
Author(s):  
Seung Won Jung ◽  
Joonsang Park ◽  
Junsoo Kang ◽  
Hyun-Jung Kim ◽  
Hyung Min Joo ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Microbial Communities ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Close Association ◽  
Time Lag ◽  
Inorganic Phosphorus ◽  
Dna Viruses ◽  
Akashiwo Sanguinea ◽  
Nucleocytoplasmic Large Dna Viruses

Abstract Background: Characterising ecological relationships between viruses, bacteria, and phytoplankton in the ocean are critical to understanding the ecosystem, yet these relationships are infrequently investigated together. To understand the dynamics of microbial communities and environmental factors in harmful algal blooms (HABs), we examined the environmental factors and microbial communities during Akashiwo sanguinea HABs in the Jangmok coastal waters of South Korea by metagenomics. Results: Specific bacterial communities showed synergistic and antagonistic relationships with A. sanguinea bloom. Endoparasitic dinoflagellate Amoebophrya sp. 1 controlled the bloom dynamics, as an increase in their abundance was correlated with HAB decline. In the nucleocytoplasmic large DNA viruses, abundance of Pandoraviridae increased following an increase in HAB. Operational taxonomic units and environmental factors associated with A. sanguinea were also visualized by network analysis: A. sanguinea-Amoebophrya sp. 1 (r=0.81, Time-lag: 2 day) and A. sanguinea-Pandoravirus dulcis (0.64, 0 day) relationships showed close association. A. sanguinea-dissolved organic carbon and -dissolved inorganic phosphorus relationships were also very closely correlated (each 0 day time-lag, respectively). Conclusions: Microbial communities and the environment dynamically and complexly changed in A. sanguinea bloom, and a rapid turnover of microorganisms could respond to ecological interactions. A. sanguinea bloom dramatically changes the environments through their exudation of dissolved carbohydrates by autotrophic processes, followed by changes in microbial communities involving host-specific viruses, bacteria, and parasitoids. Thus, microbial communities in HAB ecology are composed of various organisms and they interact in a complex way. Therefore, to interpret their ecosystem, the complex reactions among various microorganisms should be studied rather than studying a simple 1:1 reaction, such as a prey-predator interaction.

scholarly journals Auxotrophic interactions: a stabilizing attribute of aquatic microbial communities?

2020 ◽  
Vol 96 (11) ◽  
Author(s):  
Winifred M Johnson ◽  
Harriet Alexander ◽  
Raven L Bier ◽  
Dan R Miller ◽  
Mario E Muscarella ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Theoretical Work ◽  
Microbial Interactions ◽  
Ecosystem Structure ◽  
Community Members ◽  
Aquatic Microorganisms ◽  
The Stability

ABSTRACT Auxotrophy, or an organism's requirement for an exogenous source of an organic molecule, is widespread throughout species and ecosystems. Auxotrophy can result in obligate interactions between organisms, influencing ecosystem structure and community composition. We explore how auxotrophy-induced interactions between aquatic microorganisms affect microbial community structure and stability. While some studies have documented auxotrophy in aquatic microorganisms, these studies are not widespread, and we therefore do not know the full extent of auxotrophic interactions in aquatic environments. Current theoretical and experimental work suggests that auxotrophy links microbial community members through a complex web of metabolic dependencies. We discuss the proposed ways in which auxotrophy may enhance or undermine the stability of aquatic microbial communities, highlighting areas where our limited understanding of these interactions prevents us from being able to predict the ecological implications of auxotrophy. Finally, we examine an example of auxotrophy in harmful algal blooms to place this often theoretical discussion in a field context where auxotrophy may have implications for the development and robustness of algal bloom communities. We seek to draw attention to the relationship between auxotrophy and community stability in an effort to encourage further field and theoretical work that explores the underlying principles of microbial interactions.

scholarly journals A theoretical modeling framework for motile and colonial harmful algae

2021 ◽  
Author(s):  
Jackie Taylor ◽  
M. Carme Calderer ◽  
Miki Hondzo ◽  
Vaughan Voller
Keyword(s):  
Colony Formation ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Harmful Algal Bloom ◽  
Modeling Framework ◽  
Transport Dynamics ◽  
Bloom Formation ◽  
Highly Sensitive ◽  
Vertical Distributions ◽  
Colony Dynamics

1. Harmful algal blooms are increasing in both severity and frequency across the globe. Many bloom-forming species are capable of vertical motility and colony formation. The cyanobacterium Microcystis aeruginosa is a common example of such a species, yet current models poorly predict vertical distributions of M. aeruginosa. 2. To couple the hydrodynamics, buoyancy, and the colony dynamics of Microcystis, we present a system of one-dimensional advection-diffusion-aggregation equations with Smoluchowski aggregation terms. 3. Results indicate Smoluchowski aggregation accurately describes the colony dynamics of M. aeruginosa. Further, transport dynamics are strongly dependent on colony size, and aggregation processes are highly sensitive to algal concentration and wind-induced mixing. Both of these findings have direct consequences to harmful algal bloom formation. 4. While the theoretical framework outlined in this manuscript was derived for M. aeruginosa, both motility and colony formation are common among bloom-forming algae. As such, this coupling of vertical transport and colony dynamics is a useful step for improving forecasts of surface harmful algal blooms.

scholarly journals Microbial Community Dynamics and Assembly Follow Trajectories of an Early-Spring Diatom Bloom in a Semienclosed Bay

2018 ◽  
Vol 84 (18) ◽  
Author(s):  
Huajun Zhang ◽  
Kai Wang ◽  
Lixin Shen ◽  
Heping Chen ◽  
Fanrong Hou ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Nitrogen Metabolism ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Biogeochemical Cycles ◽  
Early Spring ◽  
Diatom Bloom ◽  
Ecological Processes ◽  
Content Type

ABSTRACTHarmful algal blooms (HABs) are serious ecological disasters in coastal areas, significantly influencing biogeochemical cycles driven by bacteria. The shifts in microbial communities during HABs have been widely investigated, but the assembly mechanisms of microbial communities during HABs are poorly understood. Here, using 16S rRNA gene amplicon sequencing, we analyzed the microbial communities during an early-spring diatom bloom, in order to investigate the dynamics of microbial assembly processes.Rhodobacteraceae,Flavobacteriaceae, andMicrobacteriaceaewere the main bacterial families during the bloom. The 30 most abundant operational taxonomic units (OTUs) segregated into 4 clusters according to specific bloom stages, exhibiting clear successional patterns during the bloom process. The succession of microbial communities correlated with changes in the dynamics of algal species. Based on the β-nearest taxon distance, we constructed a simulation model, which demonstrated that the assembly of microbial communities shifted from strong heterogenous selection in the early stage of the bloom to stochasticity in the middle stage and then to strong homogeneous selection in the late and after-bloom stages. These successions were driven mainly by chlorophyllacontents, which were affected mainly bySkeletonema costatum. Moreover, functional prediction of microbial communities showed that microbial metabolic functions were significantly related to nitrogen metabolism. In summary, our results clearly suggested a dominant role of determinacy in microbial community assembly in HABs and will facilitate deeper understanding of the ecological processes shaping microbial communities during the algal bloom process.IMPORTANCEHarmful algal blooms (HABs) significantly influence biogeochemical cycles driven by bacteria. The shifts in microbial communities during HABs have been studied intensively, but the assembly mechanisms of microbial communities during HABs are poorly understood, with limited investigation of the balance of deterministic and stochastic processes in shaping microbial communities in HABs. In this study, the dynamics and assembly of microbial communities in an early-spring diatom bloom process were investigated. Our data both confirm previously observed general microbial successional patterns and show new detailed mechanisms for microbial assembly in HABs. These results will facilitate deeper understanding of the ecological processes shaping microbial communities in HABs. In addition, predictions of metabolic potential in this study will facilitate understanding of the influence of HABs on nitrogen metabolism in marine environments.

Comparison of bacterial communities associated with Prorocentrum donghaiense and Karenia mikimotoi strains from Chinese coastal waters

2020 ◽  
Vol 71 (12) ◽  
pp. 1662
Author(s):  
Ruoyu Guo ◽  
Pengbin Wang ◽  
Douding Lu ◽  
Xinfeng Dai
Keyword(s):  
Coastal Waters ◽  
Bacterial Communities ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Formation Mechanisms ◽  
Prorocentrum Donghaiense ◽  
Karenia Mikimotoi ◽  
Bloom Formation ◽  
Degrading Bacteria ◽  
Different Characteristics

The dinoflagellates Karenia mikimotoi (toxic) and Prorocentrum donghaiense (non-toxic) have caused serious blooms in Chinese coastal waters. Although many studies have investigated the mechanisms underlying the harmful algal blooms of these two species, research on bacterial communities associated with K. mikimotoi and P. donghaiense is still limited. In this study, the composition of associated bacterial communities of K. mikimotoi and P. donghaiense were investigated in cultured strains. The genera with the highest relative abundance in K. mikimotoi and P. donghaiense cultures were Balneola and Marinobacter respectively. There were 26 genera specifically present in K. mikimotoi cultures, including Alteromonas, Methylophaga and Thalassospira. Sixteen genera were specifically present in P. donghaiense cultures, including an unclassified genus belonging to Nannocystaceae, Loktanella and Roseivirga. Various aromatic hydrocarbons capable of degrading bacteria were detected in the K. mikimotoi culture, but not in the P. donghaiense culture; this may contribute to the toxicity or toxin synthesis of K. mikimotoi. The results of this study provide further insights into bloom formation mechanisms and elucidate the different characteristics of K. mikimotoi and P. donghaiense blooms.

scholarly journals Dinoflagellate cysts in surface sediments at Van Phong Bay, Khanh Hoa Province, Vietnam: distribution, abundance and potentially harmful algal blooms

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Phan Tan Luom ◽  
Doan Nhu Hai ◽  
Nguyen Ngoc Lam
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Surface Sediments ◽  
Diversity Index ◽  
Dry Weight ◽  
The Other ◽  
Dinoflagellate Cysts ◽  
Toxic Dinoflagellate ◽  
Scrippsiella Trochoidea ◽  
Different Types

Studies on dinoflagellate cysts provide important knowledge on the ecology of dinoflagellates and harmful algal blooms (HABs). In this study, distribution and abundance of dinoflagellate cysts in surface sediments from 17 stations at Van Phong Bay were analyzed. There were 55 different types of cysts representing 3 orders and 18 genera, and 8 unidentified cyst types recorded. Peridiniales was the most diverse order with 29 cyst types, including 20 Protoperidinium cyst types. There were 10 cyst types of 7 potential toxic dinoflagellate species and 4 of bloom forming species found, indicating a potential risk of harmful algal blooms in Van Phong Bay. Number of cyst types and density ranged from 12 to 31 types and from 115 to 3,760 per gram of dry weight sediment, respectively. Cysts of Leonella granifera were dominant at stations in the mouth of the Bay, while Scrippsiella trochoidea cysts dominated at all stations. Shannon diversity index (H') was low, varying from 1.192.72. There were two distinct cyst assemblages identified with 40% Bray-Curtis similarity, assemblage I with 2 stations (VP09 and VP10), and assemblage II with the other stations. 

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