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harmful algal blooms

María Cristina Casero, David Velázquez, Miguel Medina-Cobo, Antonio Quesada, Samuel Cirés
Cyanobacterial harmful algal blooms (CyanoHABs) are complex communities that include coexisting toxic and non-toxic strains only distinguishable by genetic methods. This study shows a water-management oriented use of next generation sequencing (NGS) to specifically pinpoint toxigenic cyanobacteria within a bloom simultaneously containing three of the most widespread cyanotoxins (the hepatotoxins microcystins, MCs; and the neurotoxins anatoxin-a, ATX, and saxitoxins, STXs). The 2013 summer bloom in Rosarito reservoir (Spain) comprised 33 cyanobacterial OTUs based on 16S rRNA metabarcoding, 7 of which accounted for as much as 96...
February 6, 2019: Science of the Total Environment
Matthew C Randall, Gregory T Carling, Dylan B Dastrup, Theron Miller, Stephen T Nelson, Kevin A Rey, Neil C Hansen, Barry R Bickmore, Zachary T Aanderud
Lakes worldwide are impacted by eutrophication and harmful algal or cyanobacteria blooms (HABs) due to excessive nutrients, including legacy P released from sediments in shallow lakes. Utah Lake (northern Utah, USA) is a shallow lake with urban development primarily on the east side of the watershed, providing an opportunity to evaluate HABs in relation to a gradient of legacy sediment P. In this study, we investigated sediment composition and P concentrations in sediment, pore water, and the water column in relation to blooms of harmful cyanobacteria species...
2019: PloS One
Alejandro Ortiz, Jorge M Navarro, Gemita Pizarro, Paola A Villanueva, Cristian J Segura
The neurotoxic complex saxitoxin, is a group of marine toxins that historically has significantly impacted human health and the ability to utilize marine resources. A steady increase in the distribution and intensity of Alexandrium catenella blooms in Chile, and around the world, has caused major ecological and socioeconomic impacts, putting this type of dinoflagellate, and its toxicity, in the spotlight. Ostrea chilensis is a commercially and ecologically important resource harvested from wild populations and farmed in centers of southern Chile, where it is exposed to large harmful algal blooms of the type that can cause paralysis in humans...
February 4, 2019: Marine Environmental Research
Yi-Hua Lyu, Yue-Xia Zhou, Yi Li, Jin Zhou, Yi-Xiao Xu
Bacteria play an important role in preventing algal blooms and reducing their harm to the environment. To improve the algicidal activity of Pseudoalteromonas SP48 which had an inhibition effect on dinoflagellate Alexandrium tamarense, its growth medium and fermentation conditions were optimized for this bacterium. In this study, we used two steps to establish the optimum conditions. First, the proper proportion of medium was selected based on an orthogonal design. Then, the fermentation conditions were further optimized through uniform design in an enlarged 5L bioreactor...
February 7, 2019: MicrobiologyOpen
Shan Xiao, Lin Wei, Zongqin Hong, Li Rao, Yanliang Ren, Jian Wan, Lingling Feng
By using a new Fragment-Based Virtual Screen strategy, two series of novel FBA-II inhibitors (thiourea derivatives) were de novo discovered based on the active site of fructose-1, 6-bisphosphate aldolase from Cyanobacterial (CyFBA). In comparison, most of the N-(2-benzoylhydrazine-1-carbonothioyl) benzamide derivatives (L14∼L22) exhibit higher CyFBA-II inhibitory activities compared to N-(phenylcarbamothioyl) benzamide derivatives (L1∼L13). Especially, compound L14 not only shows higher CyFBA-II activity (Ki  = 0...
January 24, 2019: Bioorganic & Medicinal Chemistry
Yanbin Cui, Arvid Masud, Nirupam Aich, John D Atkinson
Lake Erie experiences annual harmful algal blooms (HAB), but generated HAB biomass may provide a waste-based precursor for environmental remediation materials. Three classes of materials (i.e., algal powder biosorbent, porous carbon, and iron/carbon (Fe/C) composite) are prepared from HAB biomass. Algal powder is nonporous with diverse functional groups. Porous carbon, prepared via one-pot carbonization and activation, has surface area up to 430 m2 /g. Fe/Cs are prepared by cultivating HAB biomass in iron-rich media, followed by one-pot pyrolysis...
January 23, 2019: Journal of Hazardous Materials
Andrea Zsuzsanna Ujvárosi, Milán Riba, Tamás Garda, Gyöngyi Gyémánt, György Vereb, Márta M-Hamvas, Gábor Vasas, Csaba Máthé
Overproduction of toxic cyanobacteria is a type of harmful algal blooms (HABs). The heptapeptide microcystins (MCs) are one of the most common cyanotoxins. There is increasing research concerning the effects of MCs on growth and physiology of vascular plants, however there is a lack of studies on their direct effects on aquatic macrophytes in the real environment. Here we report the occurrence of a MC producing HAB in Lake Bárdos, Hungary in 2012 with harmful effects on cytological, histological and biochemical parameters of Ceratophyllum submersum (soft hornwort) plants naturally growing at the blooming site...
January 22, 2019: Science of the Total Environment
Roberto Cortés-Altamirano, Rosalba Alonso-Rodríguez, David Alberto Salas-de-León
A 35-year record of algal blooms in Mazatlan Bay is reviewed in order to register bloom-forming species and their seasonal presence, duration, degree of toxicity and environmental impact. A total of 202 algal blooms have been recorded and 25 dominant species identified: 6 toxic, 5 harmful and 14 harmless species. A harmless species, Myrionecta rubra, tended to decrease in frequency, while toxic species Gymnodinium catenatum and Margalefidinium polykrikoides showed a clear trend towards an increase in frequency...
2019: PloS One
Jing Zeng, Baoling Yin, Yetang Wang, Baojuan Huai
Harmful algal blooms (HABs) are one of primary worldwide environmental problems with severe consequences for aquatic ecosystems, human health, marine fisheries and local economy. During the past few decades, coastal waters of China Seas have experienced a significant increase in the occurrence of the HAB events, which is common across the vast majority of coastal waters of the world. Here we report the absence of the widespread increase over the early 21st century in China Seas. Both frequency and coverage area of annual HAB events have decreased at statistically significant rates for the 2000-2017 period...
February 2019: Marine Pollution Bulletin
Isidro José Tamele, Marisa Silva, Vitor Vasconcelos
The occurrence of Harmful Algal Blooms (HABs) and bacteria can be one of the great threats to public health due to their ability to produce marine toxins (MTs). The most reported MTs include paralytic shellfish toxins (PSTs), amnesic shellfish toxins (ASTs), diarrheic shellfish toxins (DSTs), cyclic imines (CIs), ciguatoxins (CTXs), azaspiracids (AZTs), palytoxin (PlTXs), tetrodotoxins (TTXs) and their analogs, some of them leading to fatal outcomes. MTs have been reported in several marine organisms causing human poisoning incidents since these organisms constitute the food basis of coastal human populations...
January 21, 2019: Toxins
Xiaokai Zhang, Boling Li, Hai Xu, Mona Wells, Boris Tefsen, Boqiang Qin
Eutrophication or excessive nutrient richness is an impairment of many freshwater ecosystems and a prominent cause of harmful algal blooms. It is generally accepted that nitrogen and phosphorus nutrients are the primary causative factor, however, for systems subject to large anthropogenic perturbation, this may no longer be true, and the role of micronutrients is often overlooked. Here we report a study on Lake Tai (Taihu), a large, spatially diverse and hypereutrophic lake in China. We performed small-scale mesocosm nutrient limitation bioassays using boron, iron, cobalt, copper, molybdenum, nitrogen and phosphorus on phytoplankton communities sampled from different locations in Taihu to test the relative effects of micronutrients on in situ algal assemblages...
December 21, 2018: Water Research
Gongduan Fan, Minchen Bao, Xiaomei Zheng, Liang Hong, Jiajun Zhan, Zhong Chen, Fangshu Qu
Metal-organic Frameworks (MOFs) as a new type of nanomaterials are extensively used in various fields of environment pollution remediation. However, the MOFs are rarely applied in the removal of cyanobacterial blooms, and more fundamental investigation is warrant for more insights into mechanisms for algae inhibition. In this study, Cu-MOF-74 was synthesized by a simple hydrothermal method, and its inhibitory effect on the growth of Microcystis aeruginosa was studied. Furthermore, its mechanisms were explored with respect to metal ion release, agglomeration, shading and algal cell membrane breakage, production of extracellular hydroxyl radical and intracellular reactive oxygen species...
December 19, 2018: Journal of Hazardous Materials
Manlu Li, Yuelu Jiang, Chia-Ying Chuang, Jin Zhou, Xiaoshan Zhu, Daoyi Chen
Harmful algal blooms (HAB), heavily influenced by human activities, pose serious hazard to aquatic ecology and human health. In this study, we monitored the physiological responses and paralytic shellfish poisoning toxins (PSTs) of the toxin-producing HAB species Alexandrium tamarense under titanium dioxide nanoparticles (n TiO2 ) exposure in the concentration range of 2-320 mg L-1 over a period of 13 days. The results showed the acute inhibition of n TiO2 on the algal growth, photosynthetic efficiency and esterase activity at all concentrations except 2 mg L-1 ...
January 9, 2019: Aquatic Toxicology
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
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
Michaela E Larsson, Kirsty F Smith, Martina A Doblin
Environmental variables such as temperature, salinity and irradiance are significant drivers of microalgal growth and distribution. Therefore, understanding how these variables influence fitness of potentially toxic microalgal species is particularly important. In this study, strains of the potentially harmful epibenthic dinoflagellate species Coolia palmyrensis, C. malayensis and C. tropicalis were isolated from coastal shallow water habitats on the east coast of Australia and identified using the D1-D3 region of the large subunit (LSU) ribosomal DNA (rDNA)...
January 11, 2019: Journal of Phycology
Justine Castrec, Hélène Hégaret, Marianne Alunno-Bruscia, Maïlys Picard, Philippe Soudant, Bruno Petton, Myrina Boulais, Marc Suquet, Isabelle Quéau, Dominique Ratiskol, Valentin Foulon, Nelly Le Goïc, Caroline Fabioux
Harmful algal blooms are a threat to aquatic organisms and coastal ecosystems. Among harmful species, the widespread distributed genus Alexandrium is of global importance. This genus is well-known for the synthesis of paralytic shellfish toxins which are toxic for humans through the consumption of contaminated shellfish. While the effects of Alexandrium species upon the physiology of bivalves are now well documented, consequences on reproduction remain poorly studied. In France, Alexandrium minutum blooms have been recurrent for the last decades, generally appearing during the reproduction season of most bivalves including the oyster Crassostrea gigas...
November 27, 2018: Environmental Pollution
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