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Registros recuperados: 369 | |
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Cabecadas, L. |
Biomass and phytoplankton photosynthetic response were studied in the lower Tagus estuary weekly, and related to environmental conditions in February, March and April 1994. The Photosynthesis-Irradiance ((P-I)-I-B) relation was studied based on the light-saturated photosynthesis rate (P(B)m) and the light-limited initial slope (a(B)). The nutrient concentrations observed were high enough to be considered as not limiting phytoplankton growth. Tagus estuary phytoplankton seems, to a certain extent, adapted to high turbid conditions, being able to utilize the low light levels more efficiently, which was translated by high values of a(B) [0.10-0.20 mg C (mg Chl a)(-1) h(-1) (W m(-2))(-1)]; however, light seems to limit phytoplankton production in the water... |
Tipo: Text |
Palavras-chave: Production primaire; Phytoplancton; Estuaire; Biomasse; Turbidité; Primary production; Phytoplankton; Estuary; Biomass; Turbidity. |
Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00325/43621/43310.pdf |
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Plus, Martin; Auby, Isabelle; Maurer, Daniele; Trut, Gilles; Del Amo, Y.; Dumas, Franck; Thouvenin, Benedicte. |
This study presents an assessment of the contributions of various primary producers to the global annual production and N/P cycles of a coastal system, namely the Arcachon Bay, by means of a numerical model. This 3D model fully couples hydrodynamic with ecological processes and simulates nitrogen, silicon and phosphorus cycles as well as phytoplankton, macroalgae and seagrasses. Total annual production rates for the different components were calculated for different years (2005, 2007 and 2009) during a time period of drastic reduction in seagrass beds since 2005. The total demand of nitrogen and phosphorus was also calculated and discussed with regards to the riverine inputs. Moreover, this study presents the first estimation of particulate organic carbon... |
Tipo: Text |
Palavras-chave: Primary production; Macrophyte; Phytoplankton; Biogeochemical cycle; Physical-ecological coupled model; Arcachon bay. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00278/38963/37503.pdf |
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Lavaud, Romain; Artigaud, Sebastien; Le Grand, Fabienne; Donval, Anne; Soudant, Philippe; Flye-sainte-marie, Jonathan; Strohmeier, Tore; Strand, Oivind; Leynaert, Aude; Beker, Beatriz; Chatterjee, Arnab; Jean, Fred. |
We combined the use of pigments, fatty acids and sterols as biomarkers of the seasonal variation in food sources of the great scallop Pecten maximus. From March to October 2011, on a biweekly to twice-weekly basis, scallops and seawater from the water column and the water-sediment interface were collected in the Bay of Brest (Brittany, France). Pigment compositions in the seawater and in the stomach and rectum content of the scallops were analyzed by HPLC. Fatty acids and sterols from digestive gland (DG) tissue were analyzed by gas chromatography. Potential relationships between the temporal proportion of each marker in the environment and in the digestive tract were tested using multivariate analysis. Proportions of diatoms and Dinophyceae biomarkers... |
Tipo: Text |
Palavras-chave: Trophic ecology; Food sources; Pigments; Fatty acids; Trophic marker; Phytoplankton; Pecten maximus. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00431/54244/55772.pdf |
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Collos, Yves; Husseini Ratrema, Julie; Bec, Béatrice; Vaquer, André; Hoai, Thong Lam; Rougier, Claude; Pons, Virginie; Souchu, Philippe. |
The dilution technique was used to estimate chlorophyll and pheopigment, net and gross production as well as zooplankton grazing over a 12-month period in a coastal lagoon in Southern France. Chlorophyll a (Cha) based gross growth rates of phytoplankton ranged from undetectable in February to 2.6 day(-1) in June, corresponding to 3.8 divisions per day. Cha-based grazing rates ranged from undetectable in February to 1.1 d(-1) in June. The seasonal growth pattern of picoplankton was similar to that of the whole community, with a peak in July, corresponding to four divisions per day. Grazing processes represented from 20 to 150% of the phytoplankton daily growth, and the grazing pressure was stronger on small phytoplankton cells than on larger cells. Gross... |
Tipo: Text |
Palavras-chave: Zooplankton; Ammonium; Pheopigments; Degradation; Growth; Phytoplankton. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-727.pdf |
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Plantecuny, M; Bodoy, Alain. |
In order to estimate energetic relationship, microphytic and benthic bivalve levels of a shallow (1.5 m), sandy ecosystem near Marseille (Gulf of Fos, Southern France) were sampled monthly during 1.5 year, in two sites differing by their wave exposure. In the sheltered area, the bivalve Ruditapes decussatus was the dominant species, while another bivalve, Donax trunculus , was found in the open, wave exposed site. Chlorophyll a and primary production of the phytoplankton and the microphytobenthos, as well as population dynamic, growth and biochemical composition of bivalves (lipids, proteins and carbohydrates) were monitored. |
Tipo: Text |
Palavras-chave: Ruditapes decussatus; Bivalvia; Periphyton; Phytoplankton; Biochemical composition; Growth; Marine molluscs; Hydrodynamics; Seasonal variations; Primary production; Trophic relationships. |
Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-1528.pdf |
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Muller-feuga, Arnaud. |
Algae are utilized diversely in aquaculture, but their main applications are related to nutrition. They are used in toto, as a sole component or as a food additive to supply basic nutrients, color the flesh of salmonids or for other biological activities. The need for nutritional sources safer than traditional animal products has renewed interest in plants in general and algae in particular. This report deals principally with the nutritional role of microalgae in aquaculture.The larvae of molluscs, echinoderms and crustaceans as well as the live prey of some fish larvae feed on microalgae. Though attempts have been made to substitute inert particles for these micro-organisms which are difficult to produce, concentrate and store, only shrimp and live prey... |
Tipo: Text |
Palavras-chave: Shrimp; Post larvae; Phytoplankton; Molluscs; Microalgae; Hatchery; Fish; Aquaculture. |
Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-497.pdf |
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Souchu, Philippe; Vaquer A, André; Collos, Yves; Landrein, Sonia; Deslous-paoli, Jean-marc; Bibent, Bertrand. |
Thau lagoon is a Mediterranean shellfish ecosystem with large biomasses of oysters growing in waters with high residence time due to low tidal ranges, The influence of filter feeders (oysters and their epibiota) on the spatial distribution of particulate and dissolved compounds in the water column of Thau lagoon was studied through its variation with time, In 1991/1992, daily variations were investigated in pens, corridors and outside shellfish farming zones for nutrients, chlorophyll a and primary production. Salinity, dissolved oxygen, nutrients, organic matter and chlorophyll a were also monitored in surface waters inside and outside shellfish farming zones each week from January 1993 to March 1994. The presence of shellfish farms led to a decrease by... |
Tipo: Text |
Palavras-chave: Thau lagoon; Carrying capacity; Nutrient cycling; Phytoplankton; Suspension feeding bivalves. |
Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-808.pdf |
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Long, Marc; Paul-pont, Ika; Hegaret, Helene; Moriceau, Brivaela; Lambert, Christophe; Huvet, Arnaud; Soudant, Philippe. |
To understand the fate and impacts of microplastics (MP) in the marine ecosystems, it is essential to investigate their interactions with phytoplankton as these may affect MP bioavailability to marine organisms as well as their fate in the water column. However, the behaviour of MP with marine phytoplanktonic cells remains little studied and thus unpredictable. The present study assessed the potential for phytoplankton cells to form hetero-aggregates with small micro-polystyrene (micro-PS) particles depending on microalgal species and physiological status. A prymnesiophycea, Tisochrysis lutea, a dinoflagellate, Heterocapsa triquetra, and a diatom, Chaetoceros neogracile, were exposed to micro-PS (2 μm diameter; 3.96 μg L−1) during their growth culture... |
Tipo: Text |
Palavras-chave: Polystyrene; Microplastic; Aggregates; Microalgae; Marine; Phytoplankton. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00389/50016/50735.pdf |
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Fiala, M; Delille, B; Dubreuil, C; Kopczynska, E; Leblanc, K; Morvan, J; Queguiner, B; Blain, S; Cailliau, C; Conan, P; Corvaisier, R; Denis, M; Frankignoulle, M; Oriol, L; Roy, S. |
A mesoscale study was conducted in January and February 1999 in the Crozet Basin frontal zones (43degrees50' to 45degrees20'S, 61degrees00' to 64degrees30'E) within the southernmost and easternmost convergence area of the Antarctic Circumpolar Current (ACC) and the Agulhas Return Current (ARC). Distribution of biogeochemical parameters was strongly linked to the merged Subtropical (STF) and Subantarctic (SAF) Fronts which mark the border between the cold and less saline subantarctic waters and the warm and more saline subtropical waters. This survey took place during a post-bloom period. Chlorophyll a concentrations were low throughout the study area ranging from 0.2 mug l(-1) in the Polar Frontal Zone (PFZ) to 0.4 mug l(-1) in the Subtropical Zone (STZ).... |
Tipo: Text |
Palavras-chave: Frontal zones; Nutrients; Biogenic silica; Chlorophyll a; PCO(2); Phytoplankton; Bacteria. |
Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00224/33557/31968.pdf |
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Guesdon, Stephane; Stachowski-haberkorn, Sabine; Lambert, Christophe; Beker, Beatriz; Brach-papa, Christophe; Auger, Dominique; Bechemin, Christian. |
This study aimed to describe seasonal variations of phytoplankton abundances in relation to the physical and chemical (nutrients and metals) environment under the influence of freshwater input in the Charente river estuary (Marennes-Oléron bay, France) over three years, from 2011 to 2014. Phytoplankton abundances were determined using microscopy and flow cytometry. Considering high frequency temperature and salinity data, breakpoints in each series led to the identification of two local hydroclimatic periods: the first (2011 and early 2012) being warmer and higher in salinity than the second (from spring 2012 to the beginning of 2014). A multiblock PLS analysis highlighted the significant contribution of the physical environment (temperature, salinity and... |
Tipo: Text |
Palavras-chave: Hydroclimate; Estuary; Phytoplankton; Size composition; Nutrients; Trace metals. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00349/46005/45674.pdf |
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David, Valerie; Ryckaert, Mireille; Karpytchev, Mikhail; Bacher, Cedric; Arnaudeau, Vanessa; Vidal, Nadia; Maurer, Daniele; Niquil, Nathalie. |
Spatial and interannual variations of phytoplankton diversity were characterized along the French Atlantic Coast in relation to physical factors and large-scale climatic indices using phytoplankton surveys conducted from 1993 to 2010 in four geographical areas. This study relates phytoplankton diversity to oyster recruitment success by comparing a 'specific' versus a 'functional' diversity approach. Functional diversity was represented by functional groups of different phytoplanktonic functional traits (size, shape, toxicity), relevant for oyster feeding during growth, reproduction and larval development. Phytoplankton diversity patterns along the French Atlantic coast corresponded to a geographical distribution mainly driven by a latitudinal gradient and... |
Tipo: Text |
Palavras-chave: Phytoplankton; Long-term variation; Spatial variation; Climate; Atlantic coast. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00093/20376/19677.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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Registros recuperados: 369 | |
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