Plasticity and Multiplicity of Trophic Modes in the Dinoflagellate Karlodinium and Their Pertinence to Population Maintenance and Bloom Dynamics

As the number of mixotrophic protists has been increasingly documented, “mixoplankton”, a third category separated from the traditional categorization of plankton into “phytoplankton” and “zooplankton”, has become a new paradigm and research hotspot in aquatic plankton ecology. While species of dinoflagellates are a dominant group among all recorded members of mixoplankton, the trophic modes of Karlodinium, a genus constituted of cosmopolitan toxic species, were reviewed due to their representative features as mixoplankton and harmful algal blooms (HABs)-causing dinoflagellates. Among at least 15 reported species in the genus, three have been intensively studied for their trophic modes, and all found to be phagotrophic. Their phagotrophy exhibits multiple characteristics: (1) omnivority, i.e., they can ingest a variety of preys in many forms; (2) flexibility in phagotrophic mechanisms, i.e., they can ingest small preys by direct engulfment and much bigger preys by myzocytosis using a peduncle; (3) cannibalism, i.e., species including at least K. veneficum can ingest the dead cells of their own species. However, for some recently described and barely studied species, their tropical modes still need to be investigated further regarding all of the above-mentioned aspects. Mixotrophy of Karlodinium plays a significant role in the population dynamics and the formation of HABs in many ways, which thus deserves further investigation in the aspects of physiological ecology, environmental triggers (e.g., levels of inorganic nutrients and/or presence of preys), energetics, molecular (genes and gene expression regulations) and biochemical (e.g., relevant enzymes and signal molecules) bases, origins, and evaluation of the advantages of being a phagotroph.

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Fish Kill Incidents and Harmful Algal Blooms in Omani Waters

Journal of Agricultural and Marine Sciences [JAMS] ◽

10.24200/jams.vol16iss0pp23-33 ◽

2011 ◽

Vol 16 ◽

pp. 23 ◽

Cited By ~ 6

Author(s):

Hamed Mohammed Al Gheilani ◽

Kazumi Matsuoka ◽

Abdulaziz Yahya AlKindi ◽

Shehla Amer ◽

Colin Waring

Keyword(s):

Harmful Algal Blooms ◽

Algal Blooms ◽

Red Tide ◽

Ecological Impacts ◽

Red Tides ◽

Fish Kill ◽

Noctiluca Scintillans ◽

Trichodesmium Erythraeum ◽

Toxic Species ◽

Desalination Plants

Red tide, one of the harmful algal blooms (HABs) is a natural ecological phenomenon and often this event is accompanied by severe impacts on coastal resources, local economies, and public health. The occurrence of red tides has become more frequent in Omani waters in recent years. Some of them caused fish kill, damaged fishery resources and mariculture, threatened the marine environment and the osmosis membranes of desalination plants. However, a number of them have been harmless. The most common dinoflagellate Noctiluca scintillans is associated with the red tide events in Omani waters. Toxic species like Karenia selliformis, Prorocentrum arabianum, and Trichodesmium erythraeum have also been reported recently. Although red tides in Oman have been considered a consequence of upwelling in the summer season (May to September), recent phytoplankton outbreaks in Oman are not restricted to summer. Frequent algal blooms have been reported during winter (December to March). HABs may have contributed to hypoxia and/or other negative ecological impacts.

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Photodynamic Controls of Harmful Algal Blooms by an Ultra-efficient and Degradable AIEgen-based Photosensitizer

10.26434/chemrxiv.12471557.v1 ◽

2020 ◽

Author(s):

Qiang Yue ◽

Xuewen He ◽

Neng Yan ◽

sidan tian ◽

Chenchen LIU ◽

...

Keyword(s):

Harmful Algal Blooms ◽

Algal Blooms ◽

Water Solubility ◽

Irradiation Time ◽

Effective Means ◽

Cost Effective ◽

Weather Conditions ◽

New Paradigm ◽

Green Governance ◽

Positively Charged

Harmful <a></a><a>algal blooms</a> (HAB) have severe impacts on human health, aquatic ecosystems, and economy. There is still a lack of effective means to control the algal blooms. Herein, a positively charged photosensitizer with aggregation induced emission (AIE) characteristics, namely TVP-A, is reported for its super-efficient, cost-effective, and eco-friendly governance of HAB. TVP-A possesses a characteristically high quantum yield of harvesting white light into reactive oxygen species (ROS). Attributed to its positive charges, TVP-A has good water solubility and can quickly adsorb onto algal cells floating on the water surface. It effectively triggers cell death through oxidative destruction of the nuclei and chloroplasts of algae. The extremely low effective concentration of TVP-A and the short irradiation time by natural light in removing algal blooms ensure its application at large scales under most weather conditions, without affecting other existing organisms. The slow but consistent self-degradation of TVP-A during the photodynamic controls of algal blooms avoids generating any environmental residues or secondary pollution to environmental systems. TVP-A thereby serves as an excellent candidate for the green governance of HAB, and this work represents a new paradigm for the development of efficient and degradable AIEgens for future environmental applications.

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Photodynamic Controls of Harmful Algal Blooms by an Ultra-efficient and Degradable AIEgen-based Photosensitizer

10.26434/chemrxiv.12471557 ◽

2020 ◽

Author(s):

Qiang Yue ◽

Xuewen He ◽

Neng Yan ◽

sidan tian ◽

Chenchen LIU ◽

...

Keyword(s):

Harmful Algal Blooms ◽

Algal Blooms ◽

Water Solubility ◽

Irradiation Time ◽

Effective Means ◽

Cost Effective ◽

Weather Conditions ◽

New Paradigm ◽

Green Governance ◽

Positively Charged

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Unmanned aerial system based spectroradiometer for monitoring harmful algal blooms: A new paradigm in water quality monitoring

Journal of Great Lakes Research ◽

10.1016/j.jglr.2019.03.006 ◽

2019 ◽

Vol 45 (3) ◽

pp. 444-453 ◽

Cited By ~ 10

Author(s):

Richard H. Becker ◽

Michael Sayers ◽

Dustin Dehm ◽

Robert Shuchman ◽

Kaydian Quintero ◽

...

Keyword(s):

Water Quality ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Water Quality Monitoring ◽

Quality Monitoring ◽

Unmanned Aerial System ◽

New Paradigm

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Mini-Hydrocyclone Separation of Cyanobacterial and Green Algae: Impact on Cell Viability and Chlorine Consumption

Water ◽

10.3390/w11071473 ◽

2019 ◽

Vol 11 (7) ◽

pp. 1473

Author(s):

Saber Moradinejad ◽

Dries Vandamme ◽

Caitlin M. Glover ◽

Tahere Zadfathollah Seighalani ◽

Arash Zamyadi

Keyword(s):

Green Algae ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Separation Efficiency ◽

Scenedesmus Obliquus ◽

Free Chlorine ◽

Feed Water ◽

Toxic Species ◽

Water Matrix ◽

The Impact

The co-occurrence of non-toxic phytoplankton alongside cyanobacteria adds to the challenge of treating source waters with harmful algal blooms. The non-toxic species consume the oxidant and, thereby, reduce the efficacy of oxidation of both the extracellular and intracellular cyanotoxins. In this work, a 3D printed mini-hydrocyclone was used to separate a mixture of non-toxic green algae, Scenedesmus obliquus, from a toxic species of cyanobacteria, Microcystis aeruginosa. When water is pumped through the mini-hydrocyclone, cells exit through an overflow or underflow port depending on their size, shape, and density relative to the other cells and particles in the water matrix. The overflow port contains the cells that are smaller and less dense since these particles move toward the center of the hydrocyclone. In this work, the majority (>93%) of Microcystis cells were found in the overflow while the underflow contained primarily the Scenedesmus (>80%). This level of separation efficiency was maintained over the 30-min experiment and the majority of both cells (>86%) remained viable following the separation, which indicates that the pumping combined with forces exerted within the mini-hydrocyclone were not sufficient to cause cell death. The impact of free chlorine on the cells both pre-separation and post-separation was evaluated at two doses (1 and 2 mg/L). After separation, the overflow, which contained primarily Microcystis, had at least a 24% reduction in the free chlorine decay rate as compared to the feed water, which contained both species. This reduction in chlorine consumption shows that the cells separated via mini-hydrocyclone would likely require lower doses of oxidant to produce a similar level of degradation of the cyanotoxins present in either the extracellular or intracellular form. However, future work should be undertaken to evaluate this effect in natural bloom samples.

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Advances in the Detection of Toxic Algae Using Electrochemical Biosensors

Biosensors ◽

10.3390/bios10120207 ◽

2020 ◽

Vol 10 (12) ◽

pp. 207

Author(s):

Linda K. Medlin ◽

Maria Gamella ◽

Gerardo Mengs ◽

Verónica Serafín ◽

Susana Campuzano ◽

...

Keyword(s):

Harmful Algal Blooms ◽

Algal Blooms ◽

Detection System ◽

Amperometric Detection ◽

Toxic Algae ◽

Toxic Species ◽

Sandwich Hybridization ◽

Increased Sensitivity ◽

Novel Strategy ◽

Enzyme Molecules

Harmful algal blooms (HABs) are more frequent as climate changes and tropical toxic species move northward, especially along the Iberian Peninsula, a rich aquaculture area. Monitoring programs, detecting the presence of toxic algae before they bloom, are of paramount importance to protect ecosystems, aquaculture, human health and local economies. Rapid, reliable species identification methods using molecular barcodes coupled to biosensor detection tools have received increasing attention as an alternative to the legally required but impractical microscopic counting-based techniques. Our electrochemical detection system has improved, moving from conventional sandwich hybridization protocols using different redox mediators and signal probes with different labels to a novel strategy involving the recognition of RNA heteroduplexes by antibodies further labelled with bacterial antibody binding proteins conjugated with multiple enzyme molecules. Each change has increased sensitivity. A 150-fold signal increase has been produced with our newest protocol using magnetic microbeads (MBs) and amperometric detection at screen-printed carbon electrodes (SPCEs) to detect the target RNA of toxic species. We can detect as few as 10 cells L−1 for some species by using a fast (~2 h), simple (PCR-free) and cheap methodology (~2 EUR/determination) that will allow this methodology to be integrated into easy-to-use portable systems.

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255. Public Health Response to Harmful Algal Blooms

10.3320/1.2765781 ◽

2001 ◽

Author(s):

P. Webb

Keyword(s):

Public Health ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Public Health Response ◽

Health Response

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National coastal management challenges and needs

Shore & Beach ◽

10.34237/1008843 ◽

2020 ◽

pp. 34-43

Author(s):

Nicole Elko ◽

Tiffany Roberts Briggs

Keyword(s):

Coastal Management ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Local Community ◽

Extreme Event ◽

Technical Information ◽

Interdisciplinary Approach ◽

Beach Erosion ◽

The U.S

In partnership with the U.S. Geological Survey Coastal and Marine Hazards and Resources Program (USGS CMHRP) and the U.S. Coastal Research Program (USCRP), the American Shore and Beach Preservation Association (ASBPA) has identified coastal stakeholders’ top coastal management challenges. Informed by two annual surveys, a multiple-choice online poll was conducted in 2019 to evaluate stakeholders’ most pressing problems and needs, including those they felt most ill-equipped to deal with in their day-to-day duties and which tools they most need to address these challenges. The survey also explored where users find technical information and what is missing. From these results, USGS CMHRP, USCRP, ASBPA, and other partners aim to identify research needs that will inform appropriate investments in useful science, tools, and resources to address today’s most pressing coastal challenges. The 15-question survey yielded 134 complete responses with an 80% completion rate from coastal stakeholders such as local community representatives and their industry consultants, state and federal agency representatives, and academics. Respondents from the East, Gulf, West, and Great Lakes coasts, as well as Alaska and Hawaii, were represented. Overall, the prioritized coastal management challenges identified by the survey were: Deteriorating ecosystems leading to reduced (environmental, recreational, economic, storm buffer) functionality, Increasing storminess due to climate change (i.e. more frequent and intense impacts), Coastal flooding, both Sea level rise and associated flooding (e.g. nuisance flooding, king tides), and Combined effects of rainfall and surge on urban flooding (i.e. episodic, short-term), Chronic beach erosion (i.e. high/increasing long-term erosion rates), and Coastal water quality, including harmful algal blooms (e.g. red tide, sargassum). A careful, systematic, and interdisciplinary approach should direct efforts to identify specific research needed to tackle these challenges. A notable shift in priorities from erosion to water-related challenges was recorded from respondents with organizations initially formed for beachfront management. In addition, affiliation-specific and regional responses varied, such as Floridians concern more with harmful algal blooms than any other human and ecosystem health related challenge. The most common need for additional coastal management tools and strategies related to adaptive coastal management to maintain community resilience and continuous storm barriers (dunes, structures), as the top long-term and extreme event needs, respectively. In response to questions about missing information that agencies can provide, respondents frequently mentioned up-to-date data on coastal systems and solutions to challenges as more important than additional tools.

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