Read by QxMD icon Read

Harmful Algae

Juliette L Smith, Mengmeng Tong, David Kulis, Donald M Anderson
Previous studies indicate differences in bloom magnitude and toxicity between regional populations, and more recently, between geographical isolates of Dinophysis acuminata; however, the factors driving differences in toxicity/toxigenicity between regions/strains have not yet been fully elucidated. Here, the roles of prey strains (i.e., geographical isolates) and their associated attributes (i.e., biovolume and nutritional content) were investigated in the context of growth and production of toxins as a possible explanation for regional variation in toxicity of D...
September 2018: Harmful Algae
Carolin Peter, Bernd Krock, Allan Cembella
The marine dinoflagellate Lingulodinium polyedra is a toxigenic species capable of forming high magnitude and occasionally harmful algal blooms (HABs), particularly in temperate coastal waters throughout the world. Three cultured isolates of L. polyedra from a fjord system on the Skagerrak coast of Sweden were analyzed for their growth characteristics and to determine the effects of a strong salinity gradient on toxin cell quotas and composition. The cell quota of yessotoxin (YTX) analogs, as determined by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), ranged widely among strains...
September 2018: Harmful Algae
Qing-Chun Zhang, Ren-Cheng Yu, Zhen-Fan Chen, Li-Mei Qiu, Yun-Feng Wang, Fan-Zhou Kong, Hui-Xia Geng, Yue Zhao, Peng Jiang, Tian Yan, Ming-Jiang Zhou
Recurrent green tides have been recorded in the Yellow Sea for 11 consecutive years. The origin of floating green algae in the Yellow Sea, however, remains a subject of debate. Previous studies suggest that the major bloom-forming green alga Ulva prolifera represent a unique ecotype different from other attached populations of U. prolifera in China. In this study, 97 green algal samples collected during the 2012 green-tide event and from other locations along the coastline of China were analyzed. Based on the sequences of nuclear ribosomal RNA gene (rDNA) internal transcribed spacer (ITS) region and 5S rDNA spacer region, the green alga U...
September 2018: Harmful Algae
Zhaohe Luo, Bernd Krock, Antonia Giannakourou, Amalia Venetsanopoulou, Kalliopi Pagou, Urban Tillmann, Haifeng Gu
The marine dinoflagellate Azadinium poporum produce azaspiracids (AZA) and has been recorded widely in the world. However, information on its biogeography is still limited, especially in view of the fact that A. poporum comprises several genetically differentiated groups. A total of 18 strains of A. poporum were obtained from the Eastern Mediterranean area by incubating surface sediment collected from Ionian Sea of Greece. The morphology of these strains was examined with light microscopy and scanning electron microscopy...
September 2018: Harmful Algae
Sigitas Šulčius, Hanna Mazur-Marzec, Irma Vitonytė, Kotryna Kvederavičiūtė, Jolita Kuznecova, Eugenijus Šimoliūnas, Karin Holmfeldt
The effect of cyanophage infection and lysis on the dynamics of the hepatotoxin nodularin (NOD) and other non-ribosomal peptides (NRPs) produced by cyanobacteria is poorly understood. In this study, changes in concentration of NOD and other NRPs during cyanophage infection of the filamentous cyanobacteria Nodularia spumigena were assessed using incubation experiments. Viral infection and lysis were associated with a significant reduction (93% at the 96 h post infection) of N. spumigena cell density. While no correlation between N...
September 2018: Harmful Algae
Hwa Lin Yong, Nurin Izzati Mustapa, Li Keat Lee, Zhen Fei Lim, Toh Hii Tan, Gires Usup, Haifeng Gu, R Wayne Litaker, Patricia A Tester, Po Teen Lim, Chui Pin Leaw
Few studies have investigated the effect of fine-scale habitat differences on the dynamics of benthic harmful dinoflagellate assemblages. To determine how these microhabitat differences affect the distribution and abundance of the major benthic harmful dinoflagellate genera in a tropical coral reef ecosystem, a field study was undertaken between April-September 2015 and January 2016 on the shallow reef flat of the fringing reef of Rawa Island, Terengganu, Malaysia. Sampling of benthic dinoflagellates was carried out using an artificial substrate sampling method (fiberglass screens)...
September 2018: Harmful Algae
J Merijn Schuurmans, Bregje W Brinkmann, A Katharina Makower, Elke Dittmann, Jef Huisman, Hans C P Matthijs
Harmful cyanobacteria producing toxic microcystins are a major concern in water quality management. In recent years, hydrogen peroxide (H2 O2 ) has been successfully applied to suppress cyanobacterial blooms in lakes. Physiological studies, however, indicate that microcystin protects cyanobacteria against oxidative stress, suggesting that H2 O2 addition might provide a selective advantage for microcystin-producing (toxic) strains. This study compares the response of a toxic Microcystis strain, its non-toxic mutant, and a naturally non-toxic Microcystis strain to H2 O2 addition representative of lake treatments...
September 2018: Harmful Algae
Marianna Lanari, Margareth S Copertino, Leonir A Colling, Fábio C Bom
Macroalgal blooms can trigger adverse biogeochemical conditions at the sediment-water interface of shallow coastal areas, hence threatening critical habitats such as seagrasses meadows. The direction and magnitude of macroalgal blooms impacts on the aquatic ecosystem can be context-dependent, varying according to the local hydrodynamic conditions. Thus, studies investigating the impacts of stagnant algal depositions on the benthos may fail to address realistic situations and interactions which are common in well-flushed systems...
September 2018: Harmful Algae
Kathryn L Van Alstyne
Ulva lactuca and Ulvaria obscura are seaweeds that form green tides on Salish Sea shores. They have similar macroscopic morphologies but differ in their biochemistries and physiological responses. To understand how they are affected by changes in environmental conditions, a factorial experiment was conducted in which algae were grown in artificial seawater with either low (10 μM) or high (160 μM) nitrate (NO3 - ) concentrations at high (29 mol photons·m-2. day-1 ) and low (4 mol photons·m-2. day-1 ) light levels...
September 2018: Harmful Algae
Miaomiao Zhao, Xinyi Chen, Ning Ma, Qiuyue Zhang, Dong Qu, Ming Li
To form Microcystis blooms, Microcystis must be competitively dominant to other phytoplankton species to produce enough biomass. The aim of this study was to determine the competition mechanisms between Microcystis aeruginosa and Scenedesmus obliquus. M. aeruginosa and S. obliquus were separately cultured in the filtrate of mono and mixed cultures of M. aeruginosa and S. obliquus with varying treatments concerning N, P and iron availability. The inhibition rate for M. aeruginosa was 20-31% when cultured in mono and mixed culture filtrates enriched with N and P, but this rate was reduced to -15 to 19% when cultured in filtrates enriched with N, P and iron...
September 2018: Harmful Algae
Holly A Bowers, John P Ryan, Kendra Hayashi, April L Woods, Roman Marin, G Jason Smith, Katherine A Hubbard, Gregory J Doucette, Christina M Mikulski, Alyssa G Gellene, Yanwu Zhang, Raphael M Kudela, David A Caron, James M Birch, Christopher A Scholin
Monterey Bay, California experiences near-annual blooms of Pseudo-nitzschia that can affect marine animal health and the economy, including impacts to tourism and commercial/recreational fisheries. One species in particular, P. australis, has been implicated in the most toxic of events, however other species within the genus can contribute to widespread variability in community structure and associated toxicity across years. Current monitoring methods are limited in their spatial coverage as well as their ability to capture the full suite of species present, thereby hindering understanding of HAB events and limiting predictive accuracy...
September 2018: Harmful Algae
John R Beaver, Claudia E Tausz, Kyle C Scotese, Amina I Pollard, Richard M Mitchell
Many species of cyanobacteria are capable of producing toxins and causing nuisance blooms, however response to environmental conditions is likely taxon-specific. Environmental factors influencing cyanobacterial composition and toxin production in lakes have been examined in many studies; yet are often confined to individual water bodies, or to a small number of systems within the same region. Here, data from the 2012 USEPA National Lakes Assessment are used to examine relationships between biovolume of common potentially-toxigenic cyanobacteria (Aphanizomenon spp...
September 2018: Harmful Algae
Hee Chang Kang, Hae Jin Jeong, Kim So Jin, Ji Hyun You, Jin Hee Ok
The genus Alexandrium often forms harmful algal blooms causing human illness and large-scale mortality of fish and shellfish. Thus, Alexandrium bloom dynamics are primary concerns for scientists, government officials, aquaculture farmers, and the public. To understand bloom dynamics, mortality due to predation needs to be assessed; however, interactions between many Alexandrium species and their potential predators have not previously been reported. Thus, feeding by five common heterotrophic dinoflagellates (Oxyrrhis marina, Gyrodinium dominans, Polykrikos kofoidii, Pfiesteria piscicida, and Oblea rotunda) and a naked ciliate (Strombidinopsis sp...
September 2018: Harmful Algae
Francisco Rodríguez, Pilar Riobó, Guillermo D Crespín, Antonio H Daranas, Caterina R de Vera, Manuel Norte, José Javier Fernández, Santiago Fraga
Three strains of the toxic benthic dinoflagellate Prorocentrum hoffmannianum were isolated in the Canary Islands (north-east Atlantic Ocean, Spain). The identity of the strains was determined by phylogenetic analyses of partial LSU rDNA (D1-D2 regions) but their morphology based on SEM images corresponded to P. maculosum. Their toxin profiles were analyzed by liquid chromatography and high resolution mass spectrometry analysis (LC-HRMS) on cell extracts and culture media. Okadaic acid and three analogs were detected in all strains...
September 2018: Harmful Algae
Connor B Driscoll, Kevin A Meyer, Sigitas Šulčius, Nathan M Brown, Gregory J Dick, Huansheng Cao, Giedrius Gasiūnas, Albertas Timinskas, Yanbin Yin, Zachary C Landry, Timothy G Otten, Timothy W Davis, Susan B Watson, Theo W Dreher
In order to better understand the relationships among current Nostocales cyanobacterial blooms, eight genomes were sequenced from cultured isolates or from environmental metagenomes of recent planktonic Nostocales blooms. Phylogenomic analysis of publicly available sequences placed the new genomes among a group of 15 genomes from four continents in a distinct ADA clade (Anabaena/Dolichospermum/Aphanizomenon) within the Nostocales. This clade contains four species-level groups, two of which include members with both Anabaena-like and Aphanizomenon flos-aquae-like morphology...
July 2018: Harmful Algae
Mark W Vandersea, Steven R Kibler, Patricia A Tester, Kristine Holderied, Dominic E Hondolero, Kim Powell, Steve Baird, Angela Doroff, Darcy Dugan, R Wayne Litaker
Despite the long history of paralytic shellfish poisoning (PSP) events in Alaska, little is known about the seasonal distribution and abundance of the causative organism, Alexandrium, or the environmental factors that govern toxic bloom development. To address this issue, a five year study (2012-2017) was undertaken in Kachemak Bay and lower Cook Inlet Alaska to determine how the occurrence of Alexandrium catenella, the dominant PSP-causing Alexandrium species, was influenced by temperature, salinity, nutrient concentrations, and other environmental factors...
July 2018: Harmful Algae
Monika Dhanji-Rapkova, Alison O'Neill, Benjamin H Maskrey, Lewis Coates, Mickael Teixeira Alves, Rebecca J Kelly, Robert G Hatfield, Stephanie J Rowland-Pilgrim, Adam M Lewis, Myriam Algoet, Andrew D Turner
Official control biotoxin testing of bivalve molluscs from Great Britain has been conducted by Cefas for over a decade. Reflecting the changes in legislation, bioassays were gradually replaced by analytical methods, firstly for analysis of Paralytic shellfish toxins, followed by introduction of liquid chromatography tandem mass spectrometric (LCMS/MS) method for lipophilic toxins (LTs) in 2011. Twelve compounds, representing three main groups of regulated lipophilic toxins, as well as two non-regulated cyclic imines were examined in over 20,500 samples collected between July 2011 and December 2016...
July 2018: Harmful Algae
Rodrigo M Montes, Ximena Rojas, Paulina Artacho, Alfredo Tello, Renato A Quiñones
Harmful algal blooms (HABs) have affected salmon farms in Chile since the early 1970's, causing massive losses in fish. Two large HABs occurred in 2002 and 2009, during which Alexandrium catenella blooms killed tons of salmon over an extended geographic area in southern Chile. At the beginning of 2016, high and persistent densities of Pseudochattonella cf. verruculosa and A. catenella were detected in the estuarine and marine ecosystems of southern Chile. Mortality for this latter event reached 27 million salmon and trout (i...
July 2018: Harmful Algae
Houshuo Jiang, David M Kulis, Michael L Brosnahan, Donald M Anderson
Predator-prey interactions of planktonic protists are fundamental to plankton dynamics and include prey selection, detection, and capture as well as predator detection and avoidance. Propulsive, morphology-specific behaviors modulate these interactions and therefore bloom dynamics. Here, interactions between the mixotrophic, harmful algal bloom (HAB) dinoflagellate Dinophysis acuminata and its ciliate prey Mesodinium rubrum were investigated through quantitative microvideography using a high-speed microscale imaging system (HSMIS)...
July 2018: Harmful Algae
Mohamed Amine Hachani, Amel Dhib, Afef Fathalli, Boutheina Ziadi, Souad Turki, Lotfi Aleya
The spatio-temporal distribution of epiphytic and planktonic microalgae coupled with environmental factors was investigated for a one-year period in the Gulf of Tunis (northeastern Tunisia). Harmful microalgae assemblages were dominated by three toxic epiphytic dinoflagellates: Ostreopsis sp., Prorocentrum lima and Coolia monotis. They were observed, both on macrophytes (1.03 × 105 cells g-1 FW ; 1.3 × 104 cells g-1 FW and 865 cells g-1 FW, respectively) and in the water column (2.35 × 104 cells L-1 ; 3...
July 2018: Harmful Algae
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"