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Harmful Algae

Ricardo Bermejo, Svenja Heesch, Michéal Mac Monagail, Moya O'Donnell, Eve Daly, Robert J Wilkes, Liam Morrison
Although nutrient enrichment of estuarine and coastal waters is considered a key factor for the development of green tides, the extent, distribution, and species composition of blooms vary among systems of similar nutrient loading, which compromises our ability to predict these events based on information about nutrient status alone. Additional factors may play a role in the control and development of macroalgal blooms. The identification of relevant scales of variation is a necessary prerequisite before explanatory models can be proposed and tested...
January 2019: Harmful Algae
Silvia E Newell, Timothy W Davis, Thomas H Johengen, Duane Gossiaux, Ashley Burtner, Danna Palladino, Mark J McCarthy
Western Lake Erie (WLE) experiences anthropogenic eutrophication and annual, toxic cyanobacterial blooms of non-nitrogen (N) fixing Microcystis. Numerous studies have shown that bloom biomass is correlated with an increased proportion of soluble reactive phosphorus loading from the Maumee River. Long term monitoring shows that the proportion of the annual Maumee River N load of non-nitrate N, or total Kjeldahl nitrogen (TKN), has also increased significantly (Spearman's ρ = 0.68, p = 0.001) over the last few decades and is also significantly correlated to cyanobacterial bloom biomass (Spearman's ρ = 0...
January 2019: Harmful Algae
M Á Lezcano, R Agha, S Cirés, A Quesada
The ability of cyanobacteria to produce toxins and other secondary metabolites is patchily distributed in natural populations, enabling the use of cellular oligopeptide compositions as markers to classify strains into ecologically-relevant chemotypical subpopulations. The composition and spatiotemporal distribution of Microcystis chemotypes within and among waterbodies was studied at different time scales by analyzing (i) Microcystis strains isolated between 1998 and 2007 from different Spanish reservoirs and (ii) individual Microcystis aeruginosa colonies collected from pelagic and littoral habitats in Valmayor reservoir (Spain) during a bloom...
January 2019: Harmful Algae
Hai-Long Huang, Qian-Wen Shao, Xiao-Juan Zhu, Jie Luo, Ran Meng, Cheng-Xu Zhou, Peng Zhu, Yi-Feng Zhu, Xiao-Jun Yan
Athecate dinoflagellate Karlodinium veneficum is a universal toxic species possessing karlotoxins recognized especially as ichthyotoxic as well as cytotoxic and hemolytic. Blooms of K. veneficum, both single-species or accompanied with other species, occurred more frequently worldwide in recent years, including the coastal region of China. Normally, K. veneficum present in relatively low abundance in phytoplankton communities in estuary regions. Being small and difficult to identify with light microscopy, it has been ignored for a long time till its blooming and toxins being confirmed...
January 2019: Harmful Algae
Timothy W Davis, Richard Stumpf, George S Bullerjahn, Robert Michael L McKay, Justin D Chaffin, Thomas B Bridgeman, Christopher Winslow
Toxic cyanobacterial harmful algal blooms (cyanoHABs) are one of the most significant threats to the security of Earth's surface freshwaters. In the United States, the Federal Water Pollution Control Act of 1972 (i.e., the Clean Water Act) requires that states report any waterbody that fails to meet applicable water quality standards. The problem is that for fresh waters impacted by cyanoHABs, no scientifically-based framework exists for making this designation. This study describes the development of a data-based framework using the Ohio waters of western Lake Erie as an exemplar for large lakes impacted by cyanoHABs...
January 2019: Harmful Algae
Chao Zhang, Senjie Lin
Dinoflagellates are a major group of protists widely distributed in the aquatic environments. Many species in this lineage are able to form harmful algal blooms (HAB), some even producing toxins, making this phylum the most important contributors of HAB in the marine ecosystem. Despite the ecological importance, the molecular mechanisms underpinning the basic biology and HAB formation of dinoflagellates are poorly understood. While the high-throughput sequencing studies have documented a large and growing number of genes in dinoflagellates, their functions remained to be experimentally proven using a functional genetic tool...
January 2019: Harmful Algae
Justyna J Hampel, Mark J McCarthy, Michelle Neudeck, George S Bullerjahn, Robert Michael L McKay, Silvia E Newell
Sandusky Bay, Lake Erie, receives high nutrient loadings (nitrogen and phosphorus) from the Sandusky River, which drains an agricultural watershed. Eutrophication and cyanobacterial harmful algal blooms (cyanoHABs) persist throughout summer. Planktothrix agardhii is the dominant bloom-forming species and the main producer of microcystins in Sandusky Bay. Non-N2 fixing cyanobacteria, such as Planktothrix and Microcystis, thrive on chemically reduced forms of nitrogen, such as ammonium (NH4 + ) and urea. Ammonium regeneration and potential uptake rates and total microbial community demand for NH4 + were quantified in Sandusky Bay...
January 2019: Harmful Algae
Grant C Pitcher, Charles J Foord, Brett M Macey, Lisa Mansfield, Anna Mouton, Marie E Smith, Steven J Osmond, Lynndal van der Molen
A large dinoflagellate bloom in Walker Bay (South Africa) in January 2017 impacted 3 land-based abalone farms resulting in the death of several million animals. Satellite-derived images of Chl-a from the Ocean and Land Colour Imager (OLCI) on board the European Space Agency Sentinel-3 A showed bloom initiation in late December 2016 and dispersal in mid-February 2017. The bloom was dominated by two dinoflagellate species identified by light microscopy as Gonyaulax spinifera (Claparède & Lachmann) Diesing, 1866 and Lingulodinium polyedrum (Stein) Dodge, 1989...
January 2019: Harmful Algae
Aurélie Boisnoir, Pierre-Yves Pascal, Sébastien Cordonnier, Rodolphe Lemée
Epibenthic dinoflagellates were monitored monthly over an 18 month period in Guadeloupe and Martinique (Lesser Antilles, Caribbean Sea). These islands are located in the second most affected ciguatera fish poisoning (CFP) region of the world. Guadeloupe presented five times more total epibenthic dinoflagellates and two times less abundant Gambierdiscus spp. compared to Martinique, although the area of frequent CFP outbreaks covers Guadeloupe and not Martinique. Results did not show any clear seasonal variations of benthic dinoflagellates abundances...
January 2019: Harmful Algae
Kyung Ha Lee, Hae Jin Jeong, Kitack Lee, Peter J S Franks, Kyeong Ah Seong, Sung Yeon Lee, Moo Joon Lee, Se Hyeon Jang, Eric Potvin, An Suk Lim, Eun Young Yoon, Yeong Du Yoo, Nam Seon Kang, Kwang Young Kim
Phytoplankton production in coastal waters influences seafood production and human health and can lead to harmful algal blooms. Water temperature and eutrophication are critical factors affecting phytoplankton production, although the combined effects of warming and nutrient changes on phytoplankton production in coastal waters are not well understood. To address this, phytoplankton production changes in natural waters were investigated using samples collected over eight months, and under 64 different initial conditions, established by combining four different water temperatures (i...
January 2019: Harmful Algae
Sofie Bjørnholt Binzer, Daniel Killerup Svenssen, Niels Daugbjerg, Catharina Alves-de-Souza, Ernani Pinto, Per Juel Hansen, Thomas Ostenfeld Larsen, Elisabeth Varga
Harmful blooms formed by planktonic microalgae (HABs) in both freshwater and coastal waters regularly lead to severe mortalities of fish and invertebrates causing substantial economic losses of marine products worldwide. The mixotrophic haptophyte Prymnesium parvum is one of the most important microalgae associated with fish kills. Here 26 strains of P. parvum with a wide geographical distribution were screened for the production of prymnesins, the suspected causative allelochemical toxins. All investigated strains produced prymnesins, indicating that the toxins play an important role for the organism...
January 2019: Harmful Algae
Xinjie Wang, Xinqian Feng, Yang Zhuang, Jianghuan Lu, Yang Wang, Rodrigo J Gonçalves, Xi Li, Yongliang Lou, Wanchun Guan
A batch culture experiment was conducted to study the interactive effects of ocean acidification (OA) and solar ultraviolet radiation (UVR, 280-400 nm) on the harmful dinoflagellate Karenia mikimotoi. Cells were incubated in 7-days trials under four treatments. Physiological (growth, pigments, UVabc ) and toxicity (hemolytic activity and its toxicity to zebrafish embryos) response variables were measured in four treatments, representing two factorial combinations of CO2 (400 and 1000 μatm) and solar irradiance (with or without UVR)...
January 2019: Harmful Algae
Manthos Panou, Sevasti-Kiriaki Zervou, Triantafyllos Kaloudis, Anastasia Hiskia, Spyros Gkelis
The cyanobacterium Cylindrospermopsis raciborskii represents a challenge for researchers and it is extensively studied for its toxicity and invasive behaviour, which is presumably enhanced by global warming. Biogeography studies indicate a tropical origin for this species, with Greece considered as the expansion route of C. raciborskii in Europe. The widening of its geographic distribution and the isolation of strains showing high optimum growth temperature underline its ecological heterogeneity, suggesting the existence of different ecotypes...
December 2018: Harmful Algae
Susanna A Wood, Laura Biessy, Jonathan Puddick
Proliferations of potentially toxic, mat-forming Microcoleus are increasing in streams globally. A range of cyanotoxins are produced by Microcoleus, with the neurotoxic anatoxins (anatoxin-a, dihydro-anatoxin-a, homoanatoxin-a and dihydro-homoanatoxin-a) the most commonly reported. The anatoxins produced by Microcoleus are thought to be largely contained within the cells. More knowledge on whether anatoxins are been released into the overlying stream water is required to better assess health risks to human, animals, and aquatic organisms...
December 2018: Harmful Algae
J Sam Murray, Michael J Boundy, Andrew I Selwood, D Tim Harwood
Ciguatera fish poisoning is a serious human health issue that is highly localized to tropical and sub-tropical coastal areas, affecting many of the indigenous island communities intrinsically linked to reef systems for sustenance and trade. It is caused by the consumption of reef fish contaminated with ciguatoxins and is reported as the most common cause of non-bacterial food poisoning. The causative toxins bioaccumulate up the food web, from small herbivorous fish that graze on microalgae of the genus Gambierdiscus into the higher trophic level omnivorous and carnivorous fish predating on them...
December 2018: Harmful Algae
Xinguo Shi, Lemian Liu, Yue Li, Yuchun Xiao, Guangmao Ding, Senjie Lin, Jianfeng Chen
The relationship between algicidal bacteria and harmful-algal-bloom-forming dinoflagellates is understudied and their action modes are largely uncharacterized. In this study, an algicidal bacterium (FDHY-03) was isolated from a bloom of Prorocentrum donghaiense and the characteristics of its action against P. donghaiense was investigated at physiological, molecular, biochemical and cytological levels. 16S rDNA sequence analysis placed this strain in the genus of Alteromonas in the subclass of γ-proteobacteria...
December 2018: Harmful Algae
L Meroni, M Chiantore, M Petrillo, V Asnaghi
In the last few decades, Ostreopsis spp., toxic benthic dinolagellates of tropical origin, generated large interest in the Mediterranean Sea, where several bloom events have been observed. Ecology and proliferation dynamics of O. cf. ovata are driven by complex interactions among biotic and abiotic drivers, and understanding mechanisms triggering bloom events is still far from being complete. The aim of the present study is to highlight the role of different habitat conditions, elucidating the effects of i) exposure to hydrodynamic conditions, ii) macroalgal community and iii) urbanisation level, in driving O...
December 2018: Harmful Algae
Jorge I Mardones, Lana Shabala, Sergey Shabala, Juan José Dorantes-Aranda, Andreas Seger, Gustaaf M Hallegraeff
Harmful algal blooms (HAB) are responsible for massive mortalities of wild and aquacultured fish due to noticeable gill damage, but the precise fish-killing mechanisms remain poorly understood. A non-invasive microelectrode ion flux estimation (MIFE) technique was successfully applied to assess changes in membrane-transport processes in a model fish gill cell line exposed to harmful microplankton. Net Ca2+ , H+ , K+ ion fluxes in the rainbow trout cell line RTgill-W1 were monitored before and after addition of lysed cells of this Paralytic Shellfish Toxins (PST) producer along with purified endocellular dinoflagellate PST...
December 2018: Harmful Algae
Hae Jin Jeong, Kyung Ha Lee, Yeong Du Yoo, Nam Seon Kang, Jae Yoon Song, Tae Hoon Kim, Kyeong Ah Seong, Jae Seong Kim, Eric Potvin
Among mixotrophic dinoflagellates, the maximum mixotrophic growth rate of the red-tide dinoflagellate Paragymnodinium shiwhaense is relatively high, whereas mortality due to predation is low. To investigate the effects of major environmental parameters on P. shiwhaense, growth and ingestion rates of one strain of P. shiwhaense on the algal prey species Amphidinium carterae (also a dinoflagellate) were determined under various light intensities (0-500 μE m-2 s-1 ), water temperatures (5-30 °C), and salinities (5-40)...
December 2018: Harmful Algae
Jerilyn Ritzman, Amy Brodbeck, Sara Brostrom, Scott McGrew, Stacia Dreyer, Terrie Klinger, Stephanie K Moore
In the spring of 2015, a massive harmful algal bloom (HAB) of the toxin-producing diatom Pseudo-nitzschia occurred on the U.S. West Coast, resulting in the largest recorded outbreak of the toxin domoic acid and causing fisheries closures. Closures extended into 2016 and generated an economic shock for coastal fishing communities. This study examines the economic and sociocultural impacts of the Dungeness crab and razor clam fisheries closures on two fishing-dependent communities. Semi-structured interviews were conducted with 36 community members from two communities impacted by the event - Crescent City, California and Long Beach, Washington...
December 2018: Harmful Algae
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