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4. Nitrogen and phosphorus limitation in cultured Alexandrium minutum Halim does not promote toxin production

Author

Lassus, P. (Patrick), Arzul, G. (Geneviève), Erard-Le-Denn, E. (Evelyne), Gentien, P. (Patrick), Marcaillou-Le-Baut, C. (Claire), Flynn, Krystyna, Franco, José Mariano, Fernández, Pablo, Reguera, Beatriz, Zapata, Manuel, Flynn, Kevin, Lassus, P. (Patrick), Arzul, G. (Geneviève), Erard-Le-Denn, E. (Evelyne), Gentien, P. (Patrick), Marcaillou-Le-Baut, C. (Claire), Flynn, Krystyna, Franco, José Mariano, Fernández, Pablo, Reguera, Beatriz, Zapata, Manuel, and Flynn, Kevin

Abstract

Studies of a high- and low-toxin strains of Alexandrium minutum isolated from Ría de Vigo fail to indicate profound C-N pbysiology differences in amino acid synthesis, biomass, growth rates or pigmentation, which might explain the 10 to 20 fold differences in PSP toxin content. Maximum toxin synthesis occurs during N-refeeding of N-deprived cells and thereafter toxin content covaries with free intracellular arginine. For both strains, toxin synthesis and toxin content on a cell or biomass basis decline during N or P deprivation. Implications for changes in the toxin content of field populations are discussed.

Published
1995

9. Effect of sediment elutriate on the growth of Gymnodinium sp. (Dinophyceae). I.

Author

Fara, A., Arzul, G., Boni, L., and Giordani, P.

Abstract

Sediments from the Emilia Romagna coast, an area periodically subjected to eutrophication, were investigated to determine the organic carbon and nitrogen content from the solid phase and organic and inorganic phosphorus, nitrogen and N/P ratio from a liquid elutriate from these sediments. The elutriates were tested for growth using a bioassay with a Gymnodinium sp. which previously caused extensive blooms in the Adriatic. Cultures were grown in the elutriates either enriched or unenriched with F/2 medium. Comparisons with controls were made on the basis of the maximum standing stock. The results obtained with the unenriched elutriates demonstrated the primary role of phosphate, while enriched elutriates produced slighter enhancement than the control. In most cases, the chemical composition of the elutriate was characterized by a negligible phosphate concentration, with respect to ammonium: the nutrient balance did not agree with the nutritional algal requirement. However, all the elutriates showed large quantities of inorganic and organic nitrogen. This finding could indicate that sediment-bound nitrogen may be a ready source of nitrogen for algal growth.

Published
1994
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11. Les sites méditerranéens. Ecologie pélagique et benthique. Rapport concernant les campagnes Ecolion 1 & 2

Author

Arzul, G, Panouse, M, Romana, A, Fiala, M, Razouls, S, De Bovee, F, and Labat, J.p.

Subjects
Ecology, Ecologie, Mediterranean sea, Cruise, Mer Méditerranée, Ecolion, Campagne océanographique
Abstract

As part of its nuclear program, E.D.F. put the C.N.E.X.O. in charge of the ecological study of a list of sites that had been considered for the implantation of nuclear power plants on the Mediterranean coast: PORT-la-N0UVELLE South, PORT-la-NOUVELLE North and FLEURY-sur-AUDE. The aim of this study is to compare, from an ecological point of view, the different sites during critical periods of the annual cycle: summer and spring. This report summarises the results of the two campaigns (ECOLION l and II) conducted on the area located between the Cap d'Agde and the Cap Leucate, and including the three studied sites. The study analysed the physicochemical parameters and the primary and secondary pelagic productions, and includes a qualitative and quantitative estimate of the phytoplankton and zooplankton species (holoplankton and meroplankton). Some qualitative and quantitative estimates of the benthic fauna completed the study. This study was conducted in collaboration with the Arago laboratory in Banyuls sur mer and under L.A. ROMANA and P. CHARDY's authority., Dans le cadre de son programme nucléaire, E.D.F. a confié au Centre National pour l'exploitation des Océans, l'instruction des dossiers écologiques concernant une liste de sites envisagés pour l'implantation de centrales nucléaires sur le littoral méditerranéen: PORT-la-N0UVELLE Sud, PORT-la-NOUVELLE Nord et FLEURY-sur-AUDE. L'objectif de ce dossier est d'établir une comparaison du point de vue écologique entre les différents sites, à des moments critiques du cycle annuel: l'été et le printemps. Le présent rapport fait état des résultats obtenus lors des campagnes (ECOLION l et II) réalisées sur la zone comprise entre le Cap d'Agde et le Cap Leucate, englobant les trois sites à étudier. Les études ont porté sur les paramètres physico-chimiques et les productions primaires et secondaires pélagiques, avec estimation qualitative et quantitative des espèces du phytoplancton et du zooplancton (holoplancton et méroplancton). Des estimations qualitatives et quantitatives de la faune benthique ont permis de compléter cette étude. L'étude a été réalisée en collaboration avec le Laboratoire Arago de Banyuls sur mer et sous la responsabilité de L.A. ROMANA et P. CHARDY.

Published
1982

14. From Dinophysis spp toxicity to DSP outbreaks: A preliminary model of toxin accumulation in mussels

Author

Blanco, J., Fernández-de-Puelles, M.L. (María Luz), Mariño, J., Reguera, B. (Beatriz), Míguez, A., Maneiro, J., Cacho, E. (Emiliano), Martínez, A., Lassus, P., Arzul, G., Erard-Le-Denn, E., Gentien, P., Marcaillou-Le-Baut, C. (Claire), Lassus, P. (Patrick), Arzul, G. (Geneviève), Erard-Le-Denn, E. (Evelyne), and Gentien, P. (Patrick)

Abstract

Versión del editor

Published
1995

16. Nitrogen and phosphorus limitation in cultured Alexandrium minutum Halim does not promote toxin production

Author

Flynn, K. (Krystyna), Franco, J.M. (José Mariano), Fernández, P. (Pablo), Reguera, B. (Beatriz), Zapata, M. (Manuel), Flynn, K.J. (Kevin), Lassus, P. (Patrick), Arzul, G. (Geneviève), Erard-Le-Denn, E. (Evelyne), Gentien, P. (Patrick), and Marcaillou-Le-Baut, C. (Claire)

Subjects
Centro Oceanográfico de Vigo, Medio Marino
Abstract

Studies of a high- and low-toxin strains of Alexandrium minutum isolated from Ría de Vigo fail to indicate profound C-N pbysiology differences in amino acid synthesis, biomass, growth rates or pigmentation, which might explain the 10 to 20 fold differences in PSP toxin content. Maximum toxin synthesis occurs during N-refeeding of N-deprived cells and thereafter toxin content covaries with free intracellular arginine. For both strains, toxin synthesis and toxin content on a cell or biomass basis decline during N or P deprivation. Implications for changes in the toxin content of field populations are discussed. Publicado

Published
1995

17. Diarrhoeic toxicity induction in mussels of the Gulf of Trieste

Author

TUBARO, AURELIA, BUSSANI D., SIDARI L., HONSELL G., DELLA LOGGIA, ROBERTO, SOSA, SILVIO, LASSUS P., ARZUL G., ERARD E., GENTIEN P., MARCAILLOU LE BAUT, Tubaro, Aurelia, Sosa, Silvio, Bussani, D., Sidari, L., Honsell, G., and DELLA LOGGIA, Roberto

Published
1995

19. Effect of bentazon on growth and physiological responses of marine diatom: Chaetoceros gracilis.

Author

Hourmant A, Amara A, Pouline P, Durand G, Arzul G, and Quiniou F

Subjects
Adenosine Triphosphate metabolism, Carotenoids metabolism, Cell Respiration drug effects, Chlorophyll metabolism, Culture Media chemistry, Lipid Peroxidation, Photosynthesis drug effects, Photosystem II Protein Complex metabolism, Seawater, Thiobarbituric Acid Reactive Substances metabolism, Water Pollutants, Chemical pharmacology, Benzothiadiazines pharmacology, Diatoms drug effects, Diatoms growth & development, Herbicides pharmacology
Abstract

The herbicide bentazon (CASRN 25057-89-0) is extensively used in agriculture in Brittany (France) to replace atrazine. Bentazon is not readily adsorbed by soil and therefore it enters adjacent freshwater ecosystems, making its way to estuarine and marine waters areas. Information regarding its effects on marine ecosystems is scarce. Phytotoxicity assessments were conducted in the laboratory on the common diatom Chaetoceros gracilis using both the active ingredient and its formulated product (Basamaïs). The 3 day EC(50) using cell counts were, respectively, 150 mg/L and 60 microg/L for bentazon active ingredient and for bentazon-formulated while cellular volume was increased. Although bentazon is known as a photosystem II inhibitor, it produced an increase of pigment (chlorophylls a, c, and carotenoids) content, ATP synthesis, rates of photosynthesis and respiration, and TBARS formation. Therefore, pigments cannot be used as biomarkers of toxicity. Algal cell recovery from bentazon effects occurred after 6-9 days, suggesting a tolerance mechanism.

Published
2009
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20. In vitro test-based comparison of pesticide-induced sensitivity in marine and freshwater phytoplankton.

Author

Arzul G, Quiniou F, and Carrie C

Abstract

This study aims to assess the effects of two pesticides, namely the insecticide carbofuran and the herbicide isoproturon, on monospecifically cultivated marine and freshwater phytoplankton according to standard methods. In the presence of pesticide, growth rates were lower in marine species Chaetoceros gracilis and Phaeodactylum tricornutum than in freshwater species Chlorella vulgaris and Selenastrum capricornutum after 72 hours. The EC50 values were obtained with the REGTOX Macro software, and the NEC values by applying the DEBtox model.

Published
2006
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