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Registros recuperados: 18 | |
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Passy, Paul; Le Gendre, Romain; Garnier, Josette; Cugier, Philippe; Callens, Julie; Paris, Francois; Billen, Gilles; Riou, Philippe; Romero, Estela. |
Eutrophication of the Seine estuary and the Bay of the Seine is a crucial environmental issue for the management of ecosystems and economic activities related to fisheries and tourism. A large quantity of nutrients, especially nitrogen, is brought to the coastal zone by the Seine River, the main input of that area, but also by smaller rivers along the Normandy coast. This large delivery of nitrogen leads to an imbalance between nitrogen (N), phosphorus (P) and silica (Si), which affects the growth of planktonic organisms and can exacerbate the occurrence of harmful algal blooms (HABs). These events can be damaging for shellfish fisheries, an important economic resource for the region. The study describes a new modelling chain coupling a riverine and a... |
Tipo: Text |
Palavras-chave: Eutrophication; Harmful algal blooms; Nutrient load; Modelling; Water quality; Seine. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00300/41103/41542.pdf |
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Le Gac, Mickael; Metegnier, Gabriel; Chomerat, Nicolas; Malestroit, Pascale; Quere, Julien; Bouchez, Olivier; Siano, Raffaele; Destombe, Christophe; Guillou, Laure; Chapelle, Annie. |
Understanding divergence in the highly dispersive and seemingly homogeneous pelagic environment for organisms living as free drifters in the water column remains a challenge. Here, we analyzed the transcriptome wide mRNA sequences, as well as the morphology of 18 strains of Alexandrium minutum, a dinoflagellate responsible for Harmful Algal Blooms worldwide, to investigate the functional bases of a divergence event. Analysis of the joint site frequency spectrum (JSFS) pointed toward an ancestral divergence in complete isolations followed by a secondary contact resulting in gene flow between the two diverging groups, but heterogeneous across sites. The sites displaying fixed SNPs were associated with a highly restricted gene flow and a strong... |
Tipo: Text |
Palavras-chave: Dinoflagellates; Harmful algal blooms; Populations Genomics; Pseudocryptic species; Speciation. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00347/45857/45529.pdf |
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Lassudrie, Malwenn; Soudant, Philippe; Nicolas, Jean-louis; Miner, Philippe; Le Grand, Jacqueline; Lambert, Christophe; Le Goic, Nelly; Hegaret, Helene; Fabioux, Caroline. |
The Pacific oyster Crassostrea gigas is an important commercial species cultured throughout the world. Oyster production practices often include transfers of animals into new environments that can be stressful, especially at young ages. This study was undertaken to determine if a toxic Alexandrium bloom, occurring repeatedly in French oyster beds, could modulate juvenile oyster cellular immune responses (i.e. hemocyte variables). We simulated planting on commercial beds by conducting a cohabitation exposure of juvenile, “specific pathogen-free” (SPF) oysters (naïve from the environment) with previously field-exposed oysters to induce interactions with new microorganisms. Indeed, toxic Alexandrium spp. exposures have been reported to modulate bivalve... |
Tipo: Text |
Palavras-chave: Crassostrea gigas; Alexandrium; Harmful algal blooms; Hemocyte; Microbial challenge. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00314/42523/41894.pdf |
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Ajani, Penelope A.; Lim, Hong Chang; Verma, Arjun; Lassudrie, Malwenn; Mcbean, Katie; Doblin, Martina A.; Murray, Shauna A.. |
Certain species of the marine diatom genus Pseudo‐nitzschia are responsible for the production of the domoic acid (DA), a neurotoxin that can bioaccumulate in the food chain and cause amnesic shellfish poisoning (ASP) in animals and humans. This study extends our knowledge by reporting on the first observation of the potentially toxic species Pseudo‐nitzschia simulans from this region. One clonal strain of P. simulans was isolated from the East Australian Current and characterized using light and transmission electron microscopy, and phylogenetic analyses based on regions of the internal transcribed spacer (ITS) and the D1–D3 region of the large subunit (LSU) of the nuclear‐encoded ribosomal deoxyribonucleic acid (rDNA), as well as examined for DA... |
Tipo: Text |
Palavras-chave: Domoic acid; East Australian current; Harmful algal blooms; Phytoplankton; Shellfish. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00618/73047/75313.pdf |
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Lassudrie, Malwenn; Soudant, Philippe; Nicolas, Jean-louis; Fabioux, Caroline; Lambert, Christophe; Miner, Philippe; Le Grand, Jacqueline; Petton, Bruno; Hegaret, Helene. |
Blooms of toxic dinoflagellates can co-occur with mass mortality events associated with herpesvirus OsHV-1 μVar infection that have been decimating Pacific oyster Crassostrea gigas spat and juveniles every summer since 2008 in France. This study investigated the possible effect of a harmful dinoflagellate, Alexandrium catenella, a producer of Paralytic Shellfish Toxins (PSTs), upon the oyster spat–herpesvirus interaction. Oyster spat from a hatchery were challenged by cohabitation with oysters contaminated in the field with OsHV-1 μVar and possibly other pathogens. Simultaneously, the oysters were exposed to cultured A. catenella. Infection with OsHV-1 μVar and PST accumulation were measured after 4 days of experimental exposure. Exposure to Alexandrium... |
Tipo: Text |
Palavras-chave: Crassostrea gigas; OsHV-1 mu Var; Harmful algal blooms; Alexandrium; Host-pathogen interaction; PST accumulation. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00269/38000/36101.pdf |
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Fleming, L.e.; Mcdonough, N.; Austen, M.; Mee, L.; Moore, Michael; Hess, Philipp; Depledge, M.h.; White, M.; Philippart, Katja; Bradbrook, P.; Smalley, A.. |
The European Marine Board recently published a position paper on linking oceans and human health as a strategic research priority for Europe. With this position paper as a reference, the March 2014 Cornwall Oceans and Human Health Workshop brought together key scientists, policy makers, funders, business, and non governmental organisations from Europe and the US to review the recent interdisciplinary and cutting edge research in oceans and human health specifically the growing evidence of the impacts of oceans and seas on human health and wellbeing (and the effects of humans on the oceans). These impacts are a complex mixture of negative influences (e.g. from climate change and extreme weather to harmful algal blooms and chemical pollution) and beneficial... |
Tipo: Text |
Palavras-chave: Harmful algal blooms; Microbial pollution; Anthropogenic chemicals; Marine biotechnology; Climate change; Ocean acidification; Fisheries; Aquaculture; Seafood; Blue carbon; Marine energy; Blue gym; Ocean literacy; Risks; Benefits; EU Policy. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00192/30328/29066.pdf |
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Nascimento, Silvia M; Neves, Raquel Af; De'Carli, Gabriela Al; Borsato, Geovanna T; Da Silva, Rodrigo Af; Melo, Guilherme A; De Morais, Agatha M; Cockell, Thais C; Fraga, Santiago; Menezes-salgueiro, Adriana D; Mafra, Luis L Jr; Hess, Philipp; Salgueiro, Fabiano. |
Recurrent blooms of Ostreopsis cf. ovata have been reported in Brazil and the Mediterranean Sea with associated ecological, and in the latter case, health impacts. Molecular data based on the D1–D3 and D8–D10 regions of the LSU rDNA and ITS loci, and the morphology of O. cf. ovata isolates and field populations from locations along the Brazilian tropical and subtropical coastal regions and three oceanic islands are presented. Additional ITS sequences from three single cells from the tropical coast are provided. Toxin profiles and quantities of PLTX and their analogues; OVTXs; contained in cells from two clonal cultures and two field blooms from Rio de Janeiro were investigated. Morphology was examined using both light and epifluorescence microscopy.... |
Tipo: Text |
Palavras-chave: Benthic dinoflagellates; Harmful algal blooms; Ovatoxins; Taxonomy; Morphometry. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00604/71594/70026.pdf |
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Gonzalez-gil, Sonsoles; Velo-suarez, Lourdes; Gentien, Patrick; Ramilo, Isabel; Reguera, Beatriz. |
The distributions of Dinophysis acuminata, its potential prey Myrionecta rubra, and the microplankton populations associated with them, were studied in Ria de Pontevedra (NW Spain) during a 2 wk cruise that covered an upwelling-downwelling cycle, and during intensive sampling over 21 h at the end of the cruise. Special attention was focused on the characterization and physiological condition of D. acuminata. There was vertical segregation between a phytoplankton assemblage that was dominated by upwelling-promoted diatoms and another assemblage that was dominated by small dinoflagellates, located in the warmer surface layer (0 to 5 m) where D. acuminata was observed. High spatio-temporal variability was observed in the frequency of cells containing starch... |
Tipo: Text |
Palavras-chave: Harmful algal blooms; Plankton communities; Dinophysis acuminata; Myrionecta rubra; Predator-prey interactions. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11296/7822.pdf |
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POOT-DELGADO,Carlos Antonio; OKOLODKOV,Yuri B.; AKÉ-CASTILLO,José Antolin; RENDÓN von OSTEN.,Jaime. |
ABSTRACT Cyanobacteria inhabit hypersaline, marine and freshwater environments. Some toxic and non-toxic species can form harmful blooms. The aim of this study was to identify potentially harmful cyanobacterial species in the oyster banks of Términos Lagoon, the southeastern Gulf of Mexico. Six sample sites (up to 2-m depth) were monitored monthly from August 2012 to September 2013. Water temperature, salinity, pH, dissolved oxygen saturation (% DO), inorganic nutrients and abundance of cyanobacteria were determined. Temperature and salinity were characterized by marked seasonal differences (26.8 to 30.6 °C and 6.1 to 19.5, respectively). The pH values (ranging from 7.1 to 8.4) and the % DO (88.4 to 118.2 %) suggest a predominance of photosynthetic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Annual cycle; Cyanobacteria; Eutrophication; Gulf of Mexico; Harmful algal blooms. |
Ano: 2018 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2018000100051 |
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Thoha, Hikmah; Muawanah,; Bayu Intan, Mariana D.; Rachman, Arief; Sianturi, Oksto Ridho; Sidabutar, Tumpak; Iwataki, Mitsunori; Takahashi, Kazuya; Avarre, Jean-christophe; Masseret, Estelle. |
Margalefidinium polykrikoides, an unarmored dinoflagellate, was suspected to be the causative agent of the harmful algal blooms – associated with massive fish mortalities – that have occurred continually in Lampung Bay, Indonesia, since the first bloom event in October 2012. In this study, after examination of the morphology of putative M. polykrikoides-like cysts sampled in bottom sediments, cyst bed distribution of this harmful species was explored in the inner bay. Sediment samples showed that resting cysts, including several morphotypes previously reported as M. polykrikoides, were most abundant on the northern coast of Lampung Bay, ranging from 20.6 to 645.6 cysts g-1 dry sediment. Molecular phylogeny inferred from LSU rDNA revealed that the so-called... |
Tipo: Text |
Palavras-chave: Margalefidinium polykrikoides; Dinoflagellate; Harmful algal blooms; Resting and hyaline cysts; Indonesia. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00489/60086/63423.pdf |
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Armijo, Julien; Oerder, Vera; Auger, Pierre-amaël; Bravo, Angela; Molina, Ernesto. |
In 2016, a massive harmful algal bloom (HAB) of Alexandrium catenella around Chiloé island caused one of the major socio-ecological crisis in Chilean history. This red tide occurred in two distinct pulses, the second, most anomalous, bursting with extreme toxicity on the Pacific coast, weeks after the highly controversial dumping off Chiloé of 4,700 t of rotting salmons, killed by a previous HAB of Pseudochattonella verruculosa. We study the transport of this pollution, analyzing the physical oceanographic conditions during and after the dumping. We find that a cyclonic gyre was present between the dumping site and the coast, visible in satellite altimetry and sea surface temperature data. Using Lagrangian simulations, we confirm that near-surface currents... |
Tipo: Text |
Palavras-chave: Harmful algal blooms; Aquaculture; Pollution control; Ocean transport; Ecological crisis; Risk management. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00593/70486/69183.pdf |
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Registros recuperados: 18 | |
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