Consulta: creatorFacets:"Riso, Ricardo"
Registros recuperados: 5
Data/hora: 07/06/2024 01:18:53

The Biogeochemistry of Electroactive Humic Substances and Its Connection to Iron Chemistry in the North East Atlantic and the Western Mediterranean Sea
Provedor de dados: 5
Autores: Dulaquais, Gabriel; Waeles, Mathieu; Gerringa, Loes J. A.; Middag, Rob; Rijkenberg, Micha J. A.; Riso, Ricardo.
We present the zonal distribution of electroactive humic-like substances (eHS) along a section from Offshore Portugal in the North East Atlantic to the Sicily Channel in the Mediterranean Sea. The concentrations were normalized to Suwannee River Fulvic Acid and ranged from 11g/L to 81g/L. The vertical distributions were typical of those previously reported for dissolved organic carbon in the Mediterranean Sea. High eHS concentrations were measured in surface water and concentrations decreased with depth before increasing again toward benthic maxima measured at some stations. We estimate that eHS represented a relatively small fraction of the natural organic matter in the Mediterranean Sea (2-5%) but considering their important role in the complexation and...
Tipo: Text
Palavras-chave: Humic substances; Iron; Mediterranean Sea; Biogeochemistry; GEOTRACES.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00616/72781/72218.pdf

Cellular and biochemical responses of the oyster Crassostrea gigas to controlled exposures to metals and Alexandrium minutum
Provedor de dados: 5
Autores: Haberkorn, Hansy; Lambert, Christophe; Le Goic, Nelly; Quere, Claudie; Bruneau, A; Riso, Ricardo; Auffret, Michel; Soudant, Philippe.
Effects of simultaneous exposure of Pacific oyster, Crassostrea gigas, to both a harmful dinoflagellate that produces Paralytic Shellfish Toxins (PST), Alexandrium minutum, and cadmium (Cd) and copper (Cu), were assessed. Oysters were exposed to a mix of Cd-Cu with two different diets (i.e. A. minutum or Tisochrysis lutea) and compared to control oysters fed A. minutum or T. lutea, respectively, without metal addition. Metals and PST accumulations, digestive gland lipid composition, and cellular and biochemical hemolymph variables were measured after 4 days of exposure. Oysters exposed to Cd-Cu accumulated about thirty-six times less PSTs than oysters exposed to A. minutum alone. Exposure to Cd-Cu induced significant changes in neutral lipids (increase in...
Tipo: Text
Palavras-chave: Harmful algae; Metals; Oysters; Toxin accumulation; Physiological effects.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00169/28071/26286.pdf

Brief account of the chemical environment at hydrothermal vent mussel beds on the MAR
Provedor de dados: 5
Autores: Sarradin, Pierre-marie; Caprais, Jean-claude; Riso, Ricardo; Comtet, Thierry; Aminot, Alain.
Tipo: Text
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00186/29765/28199.pdf

Chemical environment of the hydrothermal mussel communities in the Lucky Strike and Menez Gwen vent fields, Mid Atlantic ridge
Provedor de dados: 5
Autores: Sarradin, Pierre-marie; Caprais, Jean-claude; Riso, Ricardo; Kerouel, Roger; Aminot, Alain.
Water samples were collected around the communities of a hydrothermal mussel, Bathymodiolus sp., in the Lucky Strike (1700 m depth) and Menez Gwen (850 m depth) areas, Mid Atlantic Ridge, and analysed for chemical constituents. The environment surrounding the organisms consists in sea water (88 to 100%) mixed with hydrothermal fluid with pH between 6.2 and 8, Sigma S (H2S + HS-) concentrations from 0 to 62 mu mol l(-1). High dissolved organic carbon (DOC) concentrations suggest a highly productive ecosystem. Production of ammonium and DOG, consumption of nitrate and sulfide in the vicinity of the organisms are among the environmental changes found in relation with local biological activity. Concentrations of Cu and Pb were high, implying that the organisms...
Tipo: Text
Palavras-chave: Environment; Sea water; Hydrothermal vents; Mussels.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/00147/25847/23968.pdf

Metal bioaccumulation and storage forms in the shrimp, Rimicaris exoculata, from the Rainbow hydrothermal field (Mid-Atlantic Ridge); preliminary approach to the fluid-organism relationship
Provedor de dados: 5
Autores: Geret, Florence; Riso, Ricardo; Sarradin, Pierre-marie; Caprais, Jean-claude; Cosson, Richard P.
At the Rainbow hydrothermal site the concentrations of metals in the fluid are the highest observed in the Mid-Atlantic Ridge hydrothermal areas, and the shrimps Rimicaris exoculata were observed forming dense swarms in small depressions on the chimney walls. In order to understand the fluid-organism relationship, we investigated the relative abundance of metals in the water surrounding R. exoculata and their bioaccumulation by the shrimps. This first approach stresses a net metal enrichment around R. exoculata. Precipitation, scavenging and oxidative redissolution processes in the mixing zone are controlling the concentrations of metals. Their bioaccumulation varies according to their bioavailability in the surrounding water. Metals are abundant as...
Tipo: Text
Palavras-chave: Hydrothermal fluid; Rimicaris exoculata; Metals; Bioaccumulation; Rainbow.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/00186/29762/28204.pdf