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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
Barbara C Sendall, Glenn B McGregor
Strains of the freshwater filamentous, benthic cyanobacterium Scytonema crispum Agardh isolated from six sites in subtropical south-east Queensland were characterised using a combination of phenotypic and genetic traits. Morphologically, the strains were consistent with the description of Scytonemataceae sensu stricto, and the description of Scytonema crispum. However, phylogenetic analysis of the 16S rRNA gene, the 16S-23S rRNA operon, and the nifH gene revealed that these strains and three others from outside Australia formed a monophyletic clade distinct from Scytonema and other species in the Scytonemataceae...
December 2018: Harmful Algae
Urban Tillmann, Bente Edvardsen, Bernd Krock, Kirsty F Smith, Ruth F Paterson, Daniela Voß
Azaspiracids (AZA) are a group of lipophilic polyether compounds which have been implicated in shellfish poisoning incidents around Europe. They are produced by a few species of the dinophycean genera Azadinium and Amphidoma (Amphidomataceae). The presence of AZA toxins in Norway is well documented, but knowledge of the distribution and diversity of Azadinium and other Amphidomataceae along the Norwegian coast is rather limited and poorly documented. On a research survey along the Norwegian coast in 2015 from the Skagerrak in the South to Trondheimsfjorden in the North, plankton samples from 67 stations were analysed for the presence of Azadinium and Amphidoma and their respective AZA by on-board live microscopy, real-time PCR assays specific for Amphidomataceae, and liquid chromatography-tandem mass spectrometry (LC-MS/MS)...
December 2018: Harmful Algae
Se Hyeon Jang, Hae Jin Jeong, Yeong Du Yoo
The genus Gambierdiscus produces ciguatera toxins, which has led to extensive studies of this genus. Epiphytic dinoflagellate cells were isolated from coralline macroalgae collected from the coastal waters of Jeju Island, Korea, and two clonal cultures were established. The morphology of these cells was examined using light and scanning electron microscopy, and the sequences of the small subunit (SSU), large subunit (LSU), and internal transcribed spacer (ITS) region of rDNA were determined. The phylogenetic trees based on SSU, LSU (D1-D3), and LSU (D8-D10) rDNA showed the two Korean isolates forming a clade with unidentified strains named Gambierdiscus sp...
December 2018: Harmful Algae
Stefano Accoroni, Martina Ceci, Luciana Tartaglione, Tiziana Romagnoli, Alessandra Campanelli, Mauro Marini, Sonia Giulietti, Carmela Dell'Aversano, Cecilia Totti
The benthic dinoflagellate Prorocentrum hoffmannianum M.A. Faust is typical of tropical warm waters and produces biotoxins responsible for diarrhetic shellfish poisoning (DSP). In this study, the effect of temperature and nutrient limitation on growth and toxin production of P. hoffmannianum isolated from field samples collected in the Florida Keys was investigated. Batch culture experiments were ran at two temperatures (i.e. 21 ± 0.1 and 27 ± 0.1 °C) and under nitrogen-limited (14.7 μmol L-1 N-NO3 - and 18...
December 2018: Harmful Algae
Brittanie L Dabney, Reynaldo Patiño
Glyphosate-based herbicides (GBH) are widely used around the globe. While generally toxic to phototrophs, organic phosphorus in glyphosate can become available to glyphosate-resistant phytoplankton and contribute to algal bloom development. Few studies have examined the effects of GBH on growth of eukaryotic microalgae and information for the toxic bloom-forming haptophyte, Prymnesium parvum, is limited. Using a batch-culture system, this study examined the effects on P. parvum growth of a single application of Roundup Weed and Grass Killer Super Concentrate Plus® (Roundup SC), Roundup Weed and Grass Killer Ready-to-Use III® (Roundup RtU), and technical-grade glyphosate at low concentrations [0-1000 μg glyphosate acid equivalent (ae) l-1 ]...
December 2018: Harmful Algae
Amanda J Foss, Christopher O Miles, Ingunn A Samdal, Kjersti E Løvberg, Alistair L Wilkins, Frode Rise, J Atle H Jaabæk, Peter C McGowan, Mark T Aubel
In the summer of 2012, over 750 dead and dying birds were observed at the Paul S. Sarbanes Ecosystem Restoration Project at Poplar Island, Maryland, USA (Chesapeake Bay). Clinical signs suggested avian botulism, but an ongoing dense Microcystis bloom was present in an impoundment on the island. Enzyme-linked immunosorbent assay (ELISA) analysis of a water sample indicated 6000 ng mL-1 of microcystins (MCs). LC-UV/MS analysis confirmed the presence of MC-LR and a high concentration of an unknown MC congener (m/z 1037...
December 2018: Harmful Algae
Chunyun Zhang, Guofu Chen, Yuanyuan Wang, Rui Sun, Xiaoli Nie, Jin Zhou
Harmful algal blooms (HAB) involving toxic microalgae have posed a serious threat to the marine industry and environment in the past several decades. Efficient techniques are required to monitor the marine environment to provide an effective warning of imminent HAB. Sequenced the partial large subunit rDNA (D1-D2) sequences of eight toxic harmful algae that are commonly distributed along the Chinese coast were cloned. Specific padlock probes (PLP) that contain linker regions composed of universal primer binding sites and Zip sequences were designed from the obtained target DNA...
December 2018: Harmful Algae
Aletta T Yñiguez, Jennifer Maister, Cesar L Villanoy, Josephine Dianne Deauna, Eileen Peñaflor, Aldwin Almo, Laura T David, Garry A Benico, Ellen Hibay, Irmi Mora, Sandra Arcamo, Jun Relox, Rhodora V Azanza
In contrast to temperate Harmful Algal Blooms (HABs), knowledge on the mechanisms driving tropical HABs are less well studied. The interaction of a seasonal temperature window, cysts (for certain species) and large-scale transport are some of the key processes in temperate HABs. In the Philippines, HABs occur not along long open coastlines, but in embayments that are highly influenced by run-off and stratification. These embayments are typically also the sites of cultured or wild harvest shellfish and other aquaculture activities...
December 2018: Harmful Algae
Jayme Smith, Paige Connell, Richard H Evans, Alyssa G Gellene, Meredith D A Howard, Burton H Jones, Susan Kaveggia, Lauren Palmer, Astrid Schnetzer, Bridget N Seegers, Erica L Seubert, Avery O Tatters, David A Caron
Blooms of the marine diatom genus Pseudo-nitzschia that produce the neurotoxin domoic acid have been documented with regularity along the coast of southern California since 2003, with the occurrence of the toxin in shellfish tissue predating information on domoic acid in the particulate fraction in this region. Domoic acid concentrations in the phytoplankton inhabiting waters off southern California during 2003, 2006, 2007, 2011 and 2017 were comparable to some of the highest values that have been recorded in the literature...
November 2018: Harmful Algae
Caitlin E Moyer, Emma M Hiolski, David J Marcinek, Kathi A Lefebvre, Donald R Smith, Yi Zuo
Domoic acid (DA) is a neurotoxin produced during harmful algal blooms that accumulates in marine organisms that serve as food resources for humans. While acute DA neurotoxicity can cause seizures and hippocampal lesions, less is known regarding how chronic, subacute DA exposure in adulthood impacts the hippocampus. With more frequent occurrences of harmful algal blooms, it is important to understand the potential impact of repeated, low-level DA exposure on human health. To model repeated, low-dose DA exposure, adult mice received a single low-dose (0...
November 2018: Harmful Algae
Nina Lundholm, Bernd Krock, Uwe John, Jette Skov, Jinfeng Cheng, Marina Pančić, Sylke Wohlrab, Kristie Rigby, Torkel Gissel Nielsen, Erik Selander, Sara Harðardóttir
Grazers can induce toxin (domoic acid, DA) production in diatoms. The toxic response has been observed in two species of Pseudo-nitzschia and was induced by Calanus copepods. In this study, interactions between diatoms and copepods were further explored using different species of diatoms and copepods. All herbivorous copepods induced toxin production, whereas exposure to carnivorous copepods did not. In line with this, increasing the number of herbivorous copepods resulted in even higher toxin production. The induced response is thus only elicited by copepods that pose a real threat to the responding cells, which supports that the induced toxin production in diatoms evolved as an inducible defense...
November 2018: Harmful Algae
Nancy I Lewis, Stephen S Bates, Michael A Quilliam
The commercial demand for domoic acid (DA), the phycotoxin responsible for Amnesic Shellfish Poisoning, is currently met by extraction from a diminishing supply of stockpiled contaminated mussels (Mytilus edulis). As this supply becomes scarce, a more reliable source is needed. Purification of the toxin from an algal source would be easier and more economical than from shellfish tissue if algal growth and yield of toxin were maximized. This project was initiated to determine if DA could be produced using large-scale semi-continuous algal cultures, which should reduce labour and shorten the time required for biomass production...
November 2018: Harmful Algae
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