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Velo-suarez, Lourdes; Brosnahan, Michael L.; Anderson, Donald M.; Mcgillicuddy, Dennis J., Jr.. |
Parasitic dinoflagellates of the genus Amoebophrya infect free-living dinoflagellates, some of which can cause harmful algal blooms (HABs). High prevalence of Amoebophrya spp. has been linked to the decline of some HABs in marine systems. The objective of this study was to evaluate the impact of Amoebophrya spp. on the dynamics of dinoflagellate blooms in Salt Pond (MA, USA), particularly the harmful species Alexandrium fundyense. The abundance of Amoebophrya life stages was estimated 3-7 days per week through the full duration of an annual A. fundyense bloom using fluorescence in situ hybridization coupled with tyramide signal amplification (FISH-TSA). More than 20 potential hosts were recorded including Dinophysis spp., Protoperidinium spp. and Gonyaulax... |
Tipo: Text |
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Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00170/28091/26673.pdf |
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Diaz, Patricio A.; Reguera, Beatriz; Ruiz-villarreal, Manuel; Pazos, Yolanda; Velo-suarez, Lourdes; Berger, Henrick; Sourisseau, Marc. |
In 2012, there were exceptional blooms of D. acuminata in early spring in what appeared to be a mesoscale event affecting Western Iberia and the Bay of Biscay. The objective of this work was to identify common climatic patterns to explain the observed anomalies in two important aquaculture sites, the Galician R as Baixas (NW Spain) and Arcachon Bay (SW France). Here, we examine climate variability through physical-biological couplings, Sea Surface Temperature (SST) anomalies and time of initiation of the upwelling season and its intensity over several decades. In 2012, the mesoscale features common to the two sites were positive anomalies in SST and unusual wind patterns. These led to an atypical predominance of upwelling in winter in the Galician R as,... |
Tipo: Text |
Palavras-chave: Dinophysis acuminata; Climate variability; Upwelling patterns; River plumes; Exceptional algal blooms; Predictive models. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00180/29157/27554.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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Brosnahan, Michael L.; Velo-suarez, Lourdes; Ralston, David K.; Fox, Sophia E.; Sehein, Taylor R.; Shalapyonok, Alexi; Sosik, Heidi M.; Olson, Robert J.; Anderson, Donald M.. |
Transitions between life cycle stages by the harmful dinoflagellate Alexandrium fundyense are critical for the initiation and termination of its blooms. To quantify these transitions in a single population, an Imaging FlowCytobot (IFCB), was deployed in Salt Pond (Eastham, Massachusetts), a small, tidally flushed kettle pond that hosts near annual, localized A. fundyense blooms. Machine-based image classifiers differentiating A. fundyense life cycle stages were developed and results were compared to manually corrected IFCB samples, manual microscopy-based estimates of A. fundyense abundance, previously published data describing prevalence of the parasite Amoebophrya, and a continuous culture of A. fundyense infected with Amoebophrya. In Salt Pond, a... |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00296/40737/39741.pdf |
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Alves-de-souza, Catharina; Pecqueur, David; Le Floc'H, Emilie; Mas, Sebastien; Roques, Cecile; Mostajir, Behzad; Vidussi, Franscesca; Velo-suarez, Lourdes; Sourisseau, Marc; Fouilland, Eric; Guillou, Laure. |
Dinoflagellate blooms are frequently observed under temporary eutrophication of coastal waters after heavy rains. Growth of these opportunistic microalgae is believed to be promoted by sudden input of nutrients and the absence or inefficiency of their natural enemies, such as grazers and parasites. Here, numerical simulations indicate that increasing nutrient availability not only promotes the formation of dinoflagellate blooms but can also stimulate their control by protozoan parasites. Moreover, high abundance of phytoplankton other than dinoflagellate hosts might have a significant dilution effect on the control of dinoflagellate blooms by parasites, either by resource competition with dinoflagellates (thus limiting the number of hosts available for... |
Tipo: Text |
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Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00274/38478/36938.pdf |
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Diaz, Patricio A.; Ruiz-villarreal, Manuel; Velo-suarez, Lourdes; Ramilo, Isabel; Gentien, Patrick; Lunven, Michel; Fernand, Liam; Raine, Robin; Reguera, Beatriz. |
High-resolution physical and biological measurements were carried out in May-June 2007 during the ‘HABIT-Pontevedra 2007' survey in Ría de Pontevedra (Galician Rías Baixas, NW Spain) to study small-scale physical-biological interactions in the distribution of microphytoplankton, with special emphasis on harmful species. Longitudinal transects from the Ría to the adjacent shelf were sampled to describe the spring-neap tidal and circadian variability. An in situ particle profiler, a moored ADCP, and a towed undulating CTD (Scanfish) were used during the survey, which took place after an upwelling pulse at neap tides during a downwelling–upwelling cycle and coincided with the annual maximum of Pseudo-nitzschia spp. Cell maxima of P. seriata (2×106 cells L−1)... |
Tipo: Text |
Palavras-chave: Pseudo-nitzschia spp.; Upwelling-downwelling cycle; Spring-neap tidal variability; Thin layers; Circadian variability; Galician Rias. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00157/26794/24897.pdf |
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