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harmful algal blooms

Zuomin Wang, Yuji Sakuno, Kazuhiko Koike, Shizuka Ohara
Harmful algal blooms (HABs) occur frequently in the Seto Inland Sea, bringing significant economic and environmental losses for the area, which is well known as one of the world's most productive fisheries. Our objective was to develop a quantitative model using in situ hyperspectral measurements in the Seto Inland Sea to estimate chlorophyll a (Chl- a ) concentration, which is a significant parameter for detecting HABs. We obtained spectra and Chl- a data at six stations from 12 ship-based surveys between December 2015 and September 2017...
August 13, 2018: Sensors
J Naouli, R Abouabdellah, A Bennouna, A Laissaoui, P W Swarzenski, H Ait Bouh, A Mesfioui, M-S Benbrahim, M-Y Dechraoui Bottein
Paralytic shellfish poisoning (PSP) events occur regularly along the Mediterranean and Atlantic coast of Morocco, and have been responsible for several severe cases of human intoxication. Along the southern Atlantic coast of Morocco, aquaculture and intensive artisanal fishing practices have recently been particularly heavily impacted, and toxic species have been observed in increasing intensity and frequency. In the 1990's a regulatory monitoring program was established for the coastal waters off Morocco by the National Institute of Fisheries Research (INRH), to reduce the risk of intoxication with biotoxins...
August 10, 2018: Journal of Environmental Radioactivity
Alexis D Fischer, Michael L Brosnahan, Donald M Anderson
Many dinoflagellate cysts experience dormancy, a reversible state that prevents germination during unfavorable periods. Several of these species also cause harmful algal blooms (HABs), so a quantitative understanding of dormancy cycling is desired for better prediction and mitigation of bloom impacts. This study examines the effect of cold exposure on the duration of dormancy in Alexandrium catenella, a HAB dinoflagellate that causes paralytic shellfish poisoning (PSP). Mature, dormant cysts from Nauset Marsh (Cape Cod, MA USA) were stored at low but above freezing temperatures for up to six months...
June 18, 2018: Protist
Ke Chen, Joel Allen, Jingrang Lu
The community structures of phytoplankton are important factors and indicators of lake water quality. Harmful algal blooms severely impact water supply, recreational activities and wildlife habitat. This study aimed to examine the phytoplankton composition and variations using microscopy, and identify harmful Cyanobacteria in weekly samples taken from four sites at Harsha Lake in southwest Ohio. Over the course of the summer in 2015, the phytoplankton of Harsha Lake consisted mainly of 13 taxa belonging to Bacillariophyta, Chlorophyta, Cryptophyta, Cyanobacteria, Dinophyta and Euglenophyta...
October 31, 2017: Journal of Water Resource and Protection
Marc Long, Kévin Tallec, Philippe Soudant, Christophe Lambert, Fabienne Le Grand, Géraldine Sarthou, Dianne Jolley, Hélène Hégaret
Harmful microalgal blooms are a threat to aquatic organisms, ecosystems and human health. Toxic dinoflagellates of the genus Alexandrium are known to produce paralytic shellfish toxins and to release bioactive extracellular compounds (BECs) with potent cytotoxic, hemolytic, ichtyotoxic and allelopathic activity. Negative allelochemical interactions refer to the chemicals that are released by the genus Alexandrium and that induce adverse effects on the physiology of co-occurring protists and predators. Releasing BECs gives the donor a competitive advantage that may help to form dense toxic blooms of phytoplankton...
July 27, 2018: Environmental Pollution
Fuxing Zhang, Qian Ye, Qiuliang Chen, Ke Yang, Danyang Zhang, Zhangran Chen, Shasha Lu, Xueping Shao, Yongxiang Fan, Luming Yao, Lina Ke, Tianling Zheng, Hong Xu
Prorocentrum donghaiense blooms frequently occur in the Yangtze River Estuary and the adjacent East China Sea. These blooms have damaged marine ecosystems and caused enormous economic losses over the past two decades. Thus, highly efficient, low-cost, ecofriendly approaches must be developed to control P. donghaiense blooms. In this study, a bacterial strain (Y42) was identified as Paracoccus sp. and used to lyse P. donghaiense The supernatant of the Y42 culture was able to lyse P. donghaiense, and the algicidal activity of this Y42 supernatant was stable under different temperatures and durations of light exposure and over a wide pH range...
July 27, 2018: Applied and Environmental Microbiology
Masato Yamamichi, Takehiro Kazama, Kotaro Tokita, Izumi Katano, Hideyuki Doi, Takehito Yoshida, Nelson G Hairston, Jotaro Urabe
Light is a fundamental driver of ecosystem dynamics, affecting the rate of photosynthesis and primary production. In spite of its importance, less is known about its community-scale effects on aquatic ecosystems compared with those of nutrient loading. Understanding light limitation is also important for ecosystem management, as human activities have been rapidly altering light availability to aquatic ecosystems. Here we show that decreasing light can paradoxically increase phytoplankton abundance in shallow lakes...
July 4, 2018: Proceedings. Biological Sciences
Adam Michael Lewis, Lewis Nicholas Coates, Andrew D Turner, Linda Percy, Jane Lewis
Alexandrium minutum is a globally distributed harmful algal bloom species with many strains that are known to produce paralytic shellfish toxins (PSTs) and consequently represent a concern to human and ecosystem health. This review highlights that A. minutum typically occurs in sheltered locations, with cell growth occurring during periods of stable water conditions. Sediment characteristics are important in the persistence of this species within a location, with fine sediments providing cyst deposits for ongoing inoculation to the water column...
July 26, 2018: Journal of Phycology
M Pesce, A Critto, S Torresan, E Giubilato, M Santini, A Zirino, W Ouyang, A Marcomini
There is high confidence that the anthropogenic increase of atmospheric greenhouse gases (GHGs) is causing modifications in the Earth's climate. Coastal waterbodies such as estuaries, bays and lagoons are among those most affected by the ongoing changes in climate. Being located at the land-sea interface, such waterbodies are subjected to the combined changes in the physical-chemical processes of atmosphere, upstream land and coastal waters. Particularly, climate change is expected to alter phytoplankton communities by changing their environmental drivers (especially climate-related), thus exacerbating the symptoms of eutrophication events, such as hypoxia, harmful algal blooms (HAB) and loss of habitat...
July 1, 2018: Science of the Total Environment
Karold Viviana Coronado-Franco, John Josephraj Selvaraj, José Ernesto Mancera Pineda
The current capacity in the Caribbean region to enhance the knowledge about algal blooms and harmful algal blooms has several logistical constraints. This work aimed to explore the detection of possible algal blooms using Moderate Resolution Imaging Spectroradiometer (MODIS) Fluorescence Line Height (FLH) data in the Colombian Caribbean Sea between 2003 and 2013. Monthly FLH images with 4 km of spatial resolution were processed and classified. The relationship between the Sea Surface Temperature (SST) and the FLH were explored using a Geographically Weighted Regression...
August 2018: Marine Pollution Bulletin
Aseem R Rath, Smita Mitbavkar, Arga Chandrashekar Anil
Seasonal and spatial phytoplankton distribution in relation to environmental factors was investigated in New Mangalore Port, a major port along the west coast of India. A well-mixed water column characterized the non-monsoon seasons, whereas it was weakly stratified during monsoon. Water quality index (TRIX) scores indicated good water quality except during pre-monsoon (inner zone surface) and monsoon (near bottom waters). Surface abundance of tychopelagic diatoms (Paralia sulcata, Melosira nummuloides, Cylindrotheca closterium, and Nitzschia sigma) was higher during non-monsoon seasons...
July 23, 2018: Environmental Monitoring and Assessment
Huajun Zhang, Kai Wang, Lixin Shen, Heping Chen, Fanrong Hou, Xiaoyan Zhou, Demin Zhang, Xiangyu Zhu
Harmful algal blooms (HABs) are serious ecological disasters in coastal areas, significantly influencing biogeochemical cycles driven by bacteria. The shifts in microbial communities during HABs have been widely investigated, yet the assembly mechanism of microbial communities during HABs is poorly understood. Here using 16S rRNA gene amplicon sequencing, we analyzed the microbial communities during an early spring diatom bloom, in order to investigate the dynamics of microbial assembly process. Rhodobacteraceae , Flavobacteriaceae, and Microbacteriaceae were the main bacterial families during the bloom...
July 13, 2018: Applied and Environmental Microbiology
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
Jiangbing Qiu, Cheryl Rafuse, Nancy I Lewis, Aifeng Li, Fanping Meng, Daniel G Beach, Pearse McCarron
The dinoflagellate genus Alexandrium Halim has frequently been associated with harmful algal blooms. Although a number of species from this genus are known to produce paralytic shellfish toxins (PST) and/or cyclic imines (CI), studies on comprehensive toxin profiling using techniques capable of detecting the full range of PST and CI analogues are limited. Isolates of Alexandrium spp. from Atlantic Canada were analyzed by targeted and untargeted liquid chromatography-tandem mass spectrometry (LC-MS). Results showed a number of distinct profiles and wide ranging cell quotas of PST and spirolides (SPX) in both A...
July 2018: Harmful Algae
Huan Wang, Rong Zhu, Jia Zhang, Leyi Ni, Hong Shen, Ping Xie
The occurrence of algal blooms in drinking water sources and recreational water bodies have been increasing and causing severe environmental problems worldwide, particularly when blooms dominated by Microcystis spp. Bloom prediction and early warning mechanisms are becoming increasingly important for preventing harmful algal blooms in freshwater ecosystems. Chlorophyll fluorescence parameters (CFpars) have been widely used to evaluate growth scope and photosynthetic efficiency of phytoplankton. According to our 2-year monthly monitor datasets in Lake Erhai, a simple but convenient method was established to predict Microcystis blooms and algal cell densities based on a CFpar representing maximal photochemical quantum yield of Photosystems II (PSII) of algae...
2018: Frontiers in Plant Science
Ja Young Cho, Joong Kyun Kim
To help remedy damage from harmful algal blooms, an attempt was made to isolate an algicidal substance previously observed to be present in mackerel muscle hydrolysate. Crude extract was obtained by cold acetone precipitation, and it dissolved best in water. Through molecular weight cut-off determination and tricine-SDS PAGE, the algicidal substance was determined to be a peptide of <1 kDa. Based on this result, purification was first performed using size exclusion chromatography and preparative reverse phase high-performance liquid chromatography...
September 1, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Simon Pouil, Rachel J Clausing, Marc Metian, Paco Bustamante, Marie Yasmine Dechraoui-Bottein
Marine organisms are exposed to and affected by a multitude of chemicals present in seawater and can accumulate in their tissues a wide range of contaminants as well as natural biotoxins associated with harmful algal blooms (HABs). Trace elements and biotoxins may modify physiological functions in exposed organisms, and studies have been conducted to better understand their respective kinetics and effects in marine species. Despite the increasing concern of concurrent toxic HABs and pollution events due to anthropogenic pressures and global change, very little information is available on their combined effects...
July 6, 2018: Journal of Environmental Radioactivity
Igor Mrdjen, Jiyoung Lee
Microcystin (MC) is a hepatotoxin produced by various cyanobacteria during harmful algal blooms (HAB's) in freshwater environments. Advanced treatment methods can remove MC from drinking water, but are costly and do not address recreational water exposure and ecosystem health concerns. Here we investigate the feasibility of utilizing plastics as a MC-adsorbing material, for use in water resources used for recreation, agriculture, aquaculture and drinking water. Water containing 20 µg/L MC-LR was exposed to polypropylene (PP) plastic for a six-day period at varying temperatures (22, 37, 65°C)...
July 9, 2018: Journal of Environmental Science and Health. Part A, Toxic/hazardous Substances & Environmental Engineering
Murendeni Magonono, Paul Johan Oberholster, Shonhai Addmore, Makumire Stanley, Jabulani Ray Gumbo
The presence of harmful algal blooms (HABs) and cyanotoxins in drinking water sources poses a great threat to human health. The current study employed molecular techniques to determine the occurrence of non-toxic and toxic cyanobacteria species in the Limpopo River basin based on the phylogenetic analysis of the 16S rRNA gene. Bottom sediment samples were collected from selected rivers: Limpopo, Crocodile, Mokolo, Mogalakwena, Nzhelele, Lephalale, Sand Rivers (South Africa); Notwane (Botswana); and Shashe River and Mzingwane River (Zimbabwe)...
July 3, 2018: Toxins
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