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| Registros recuperados: 369 | |
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| Dupouy, Cecile; Wattelez, Guillaume; Lefevre, Jerome; Juillot, Farid; Andreoli, Remi; Lille, Didier; Murakami, Hiroshi; Roettgers, Rudiger; Frouin, Robert. |
| Shortly after strong rains or tropical storms, chlorophyll-a concentration (Chla), turbidity, and colored dissolved organic matter (CDOM) in the lagoon of New Caledonia may be tripled. This effect is visible as far as 50 km offshore. The Eastern Coast of New Caledonia is more impacted than the Western Coast because of its geomorphological structure. Higher frequency and intensity of the rains, and the dominance of highly erosive lateritic formations resulted from deep weathering of ultramafic rocks. At the deeper parts of the lagoon (> 20 m), increases of Chla, turbidity, and CDOM absorption can be detected by satellite imagery with their plumes extending off shore as a result of wind-driven circulation in the lagoon. Such -increases agree with the... |
| Tipo: Text |
Palavras-chave: Minerals; Phytoplankton; CDOM; FDOM; Ocean color; Reflectance; New Caledonia; Tropical Pacific Ocean; Lagoons. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00481/59308/62064.pdf |
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| Kurata, A. |
| The changes in concentration of thiamine, biotin and vitamin B sub(12) in water of the soaked bottles for 6 h in situ in the north basin of Lake Biwa were examined successively over 30 hours. The concentrations of the vitamins changed comparatively during 6 h. soaking in situ. Generally, the concentrations of thiamine, biotin and vitamin B sub(12) were in high levels in the morning and in low levels in evening both in the soaked bottles and in the surrounding water. The fluctuation ranges in concentration of vitamins in a 5 m deep layer were greater than those in thermocline. From the data obtained with the soaked bottles in situ, it was supposed that the decrease of vitamins in concentration during the daytime surpass consumption of vitamins by... |
| Tipo: Text |
Palavras-chave: Phytoplankton; Microorganisms; Bacteria; Metabolism; Biological production; Vitamin B; Fresh water. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-958.pdf |
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| Savoye, N; Aminot, Alain; Treguer, Paul; Fontugne, M; Naulet, N; Kerouel, Roger. |
| Two cruises (April and June 1997) were carried out in the Bay of Seine, a nitrate- and ammonium-enriched ecosystem of Western Europe, to identify the major mechanisms that control delta(15)N and VC in spring particulate organic matter (POM). Particulate organic nitrogen (PON) delta(15)N ranged between 0.8 and 5.2parts per thousand in April and between 2.2 and 6.2parts per thousand in June, while particulate organic carbon (POC) delta(13)C ranged between -24.3 and -19.7parts per thousand, and between -20.0 and -16.2parts per thousand during the same periods. During spring 1997, POM was highly dominated by autochthonous phytoplankton. It is shown that the variation of PON delta(15)N is due to both nitrate mixing between river and marine waters and... |
| Tipo: Text |
Palavras-chave: C and N stable isotopes; Phytoplankton; Coastal ecosystem; Nitrate utilization; Bay of Seine. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00000/10645/7593.pdf |
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| Zendong, Suzie Zita; Kadiri, Medina; Herrenknecht, Christine; Nezan, Elisabeth; Mazzeo, Antonia; Hess, Philipp. |
| Algal toxins may accumulate in fish and shellfish and thus cause poisoning in consumers of seafood. Such toxins and the algae producing them are regularly surveyed in many countries, including Europe, North America, Japan and others. However, very little is known regards the occurrence of such algae and their toxins in most African countries. This paper reports on a survey of phytoplankton and algal toxins in Nigerian coastal waters. Seawater samples were obtained from four sites for phytoplankton identification, on three occasions between the middle of October 2014 and the end of February 2015 (Bar Beach and Lekki in Lagos State, Port Harcourt in Rivers State and Uyo in Akwa Ibom State). The phytoplankton community was generally dominated by diatoms and... |
| Tipo: Text |
Palavras-chave: Dinoflagellates; Dinophysis; Phycotoxins; Untargeted analysis; Phytoplankton. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00314/42521/41893.pdf |
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| Raybaud, V.; Tunin-ley, A.; Ritchie, M. E.; Dolan, J. R.. |
| Planktonic populations were sampled over a 4 week period in the NW Mediterranean, at a site subject to little vertical advection during the Dynaproc 2 cruise in 2004. The characteristics of the phytoplankton, the tintinnid community and the zooplankton have recently been described in detail. Based on these studies, we compared the characteristics of 3 well-circumscribed assemblages of different trophic levels: Ceratium of the phytoplankton, herbivorous tintinnids of the microzooplankton, and large (> 500 mu m) omnivorous and carnivorous copepods of the metazoan zooplankton. In all three groups, diversity as H' or species richness, was less variable than concentration of organisms. Plotting time against species accumulation, the curves approached plateau... |
| Tipo: Text |
Palavras-chave: Species abundance distributions; Diversity; Zooplankton; Microzooplankton; Phytoplankton; Biodiversity. |
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00208/31970/30411.pdf |
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| El Hourany, Roy; Abboud-abi Saab, Marie; Faour, Ghaleb; Mejia, Carlos; Crepon, Michel; Thiria, Sylvie. |
| We present a new method to identify phytoplankton functional types (PFTs) in the Mediterranean Sea from ocean color data (GlobColour data in the present study) and AVHRR sea surface temperature. The principle of the method is constituted by two very fine clustering algorithms, one mapping the relationship between the satellite data and the pigments and the other between the pigments and the PFTs. The clustering algorithms are constituted of two efficient self-organizing maps, which are neural network classifiers. We were able to identify and estimate the percentage of six PFTs: haptophytes, chlorophytes, cryptophytes, Synechococcus, Prochlorococcus, and diatoms. We found that these PFTs present a peculiar variability due to the complex physical and... |
| Tipo: Text |
Palavras-chave: Phytoplankton; Secondary phytoplankton pigments; Self-organizing maps; Classification; Mediterranean Sea; Remote sensing. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00589/70145/68135.pdf |
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| Dupouy, Cécile; Röttgers, Rüdiger; Tedetti, Marc; Frouin, Robert; Lantoine, François; Rodier, Martine; Martias, Chloe; Goutx, Madeleine. |
| New Caledonia (Southwest Pacific), like all tropical Pacific Island countries, is impacted by weather events, climate change, and local anthropogenic forcing. Strong erosion of particles and dissolved organic matter (DOM) from ultramafic rocks, associated with trace metals dissemination (i.e., nickel, manganese and cobalt), potentially affects lagoon waters and coral reefs surrounding the main island. The CALIOPE (CALedonian Inherent Optical PropErties) cruises were performed along the Eastern Lagoon of New Caledonia (ELNC) (400 km, 13 transects from Bay to open ocean, 51 stations) during contrasted meteorological conditions: a dry period (October 2011), a windy situation (March 2014), and a strong rainy event (March 2016). CDOM absorption and fluorescence... |
| Tipo: Text |
Palavras-chave: Chromophoric dissolved organic matter; Fluorescence; New Caledonia; Tropical Pacific; Lagoons; Biooptics; Phytoplankton; Rivers. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00620/73166/72352.pdf |
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| Dhurmeea, Zahirah; Pethybridge, Heidi; Langlais, Clothilde; Somes, Christopher J.; Nikolic, Natacha; Bourjea, Jerome; Appadoo, Chandani; Bodin, Nathalie. |
| Albacore tuna (Thunnus alalunga) is a highly economically important species in the western Indian Ocean. However, knowledge of its ecological and nutritional characteristics, essential for proper management of the species, is lacking in the region. The trophodynamics of the Indian Ocean albacore was thus examined using known fatty acid trophic markers (FATMs) of primary producers, nutritional condition indices (NCIs) (omega-3/omega-6 ratio and total fatty acid content (TFA)), and baseline and lipid corrected stable isotope of carbon (δ13Ccorr) and nitrogen (δ15Ncorr), measured in the muscle tissue. We applied generalized additive mixed models to understand the spatiotemporal patterns and drivers of these tracers, taking into consideration several intrinsic... |
| Tipo: Text |
Palavras-chave: Trophodynamics; Phytoplankton; Environmental parameters; Climate change. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00623/73497/72787.pdf |
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| Bergeron, Jean-pierre; Herbland, Alain. |
| Estimates of carbohydrate assimilation within the mesozooplankton compartment are a fundamental concern in oceanography because they give a general expression of the biologically-regulated incorporation of metabolic fuel produced from inorganic nutrients by phytoplankton in the sea. A new tool is proposed for the assessment of such processes. It is based on the measurement of the activity of an enzyme, pyruvate kinase (PK), on samples of the whole mesozooplankton community. Here, the results are presented of an early attempt at such an implementation in the Bay of Biscay (north-east Atlantic) in springtime. A main area situated in front of an estuary (Gironde) has been extensively studied-the same sampling grid was covered on three occasions (two 20 day... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Zooplankton; Phytoplankton; Pyruvate kinase; Carbohydrate. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-452.pdf |
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| Soudant, Dominique; Beliaeff, Benoit; Thomas, G. |
| Classical regression analysis can be used to model time series. However, the assumption that model parameters are constant over time is not necessarily adapted to the data. In phytoplankton ecology, the relevance of time-varying parameter values has been shown using a dynamic linear regression model (DLRM). DLRMs, belonging to the class of Bayesian dynamic models, assume the existence of a non-observable time series of model parameters, which are estimated on-line, i.e. after each observation. The aim of this paper was to show how DLRM results could be used to explain variation of a time series of phytoplankton abundance. We applied DLRM to daily concentrations of Dinophysis cf. acuminata, determined in Antifer harbour (French coast of the English... |
| Tipo: Text |
Palavras-chave: Phytoplankton; Dinophysis; Time series; Regression; Dynamic; Bayesian. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00337/44784/44490.pdf |
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| Derolez, Valerie; Bec, Béatrice; Grillas, Patrice; Sanchez, Ana Elena; Raimbault, Patrick. |
| In the context of WFD implementation on Mediterranean lagoons, work has been carried out since 2010 by Ifremer, Tour du Valat and IRSTEA (Onema and AERM & C fundings), to assess the relevance of macrophytes and macrofauna indicators for oligohaline and mesohaline lagoons (mean salinity <18 PSU). The question of the relevance of indicator metrics and thresholds for the "phytoplankton" biological quality element also arises, especially due to the confined nature of olgo-mesohaline lagoons. The objective of this study is to characterize the abundance and composition of phytoplankton on 5 oligo and mesohaline lagoons of the French Mediterranean coast (Scamandre, Crey, Charnier, Bolmon and Grand Palun). Analyses of accessory pigments (chlorophyll and... |
| Tipo: Text |
Palavras-chave: Lagunes; Méditerranée; Oligohalin; Mésohalin; Phytoplancton; Cytométrie; Pigments chlorophylliens; Lagoons; Mediterranean Sea; Oligohaline; Mesohaline; Phytoplankton; Cytometry; Chlorophyll pigments.. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00357/46816/46682.pdf |
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| Registros recuperados: 369 | |
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