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Bouquegneau Jean-marie - One of the best experts on this subject based on the ideXlab platform.
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Récentes menaces de pollution par les éléments traces pesant sur l'écosystème côtier: une étude multiélémentaire
2009Co-Authors: Richir Jonathan, Gobert Sylvie, Bouquegneau Jean-marieAbstract:The Mediterranean Sea is an enclosed basin, highly submitted to anthropogenic pressures. Chemical pollution from coastal urban centres and industries, or carried by air and rivers, primarily affects its coastal ecosystems. Pollution by trace elements is rapidly evolving further to the recent modifications of their production and industrial uses by men. As a result, certain trace elements can now be considered as new environmental pollutants. Appropriate bioindicators are useful tools for the early warning of marine pollution. We presently investigate the use of the purple sea urchin Paracentrotus lividus and the marine Phanerogam Posidonia oceanica as bioindicators to monitor the Mediterranean coastal pollution by new trace pollutants (Be, V, Mo, Mn, PGEs, Ag, Al, As, Se, Sb and Bi). Classic trace metals (Cd, Cr, Cu, Zn, Ni, Sn, Pb, Co and Fe) are also studied. Organisms were seasonally collected in 2008 in a reference site and a polluted one, respectively Calvi bay (Corsica) and Marseille (France). Their tissular trace element concentrations were determined by ICP-MS. All the investigated trace elements were chosen for their potential toxic effects.Peer reviewe
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Récentes menaces de pollution par les éléments traces pesant sur l'écosystème côtier: une étude multiélémentaire
2009Co-Authors: Richir Jonathan, Gobert Sylvie, Bouquegneau Jean-marieAbstract:peer reviewedaudience: researcherThe Mediterranean Sea is an enclosed basin, highly submitted to anthropogenic pressures. Chemical pollution from coastal urban centres and industries, or carried by air and rivers, primarily affects its coastal ecosystems. Pollution by trace elements is rapidly evolving further to the recent modifications of their production and industrial uses by men. As a result, certain trace elements can now be considered as new environmental pollutants. Appropriate bioindicators are useful tools for the early warning of marine pollution. We presently investigate the use of the purple sea urchin Paracentrotus lividus and the marine Phanerogam Posidonia oceanica as bioindicators to monitor the Mediterranean coastal pollution by new trace pollutants (Be, V, Mo, Mn, PGEs, Ag, Al, As, Se, Sb and Bi). Classic trace metals (Cd, Cr, Cu, Zn, Ni, Sn, Pb, Co and Fe) are also studied. Organisms were seasonally collected in 2008 in a reference site and a polluted one, respectively Calvi bay (Corsica) and Marseille (France). Their tissular trace element concentrations were determined by ICP-MS. All the investigated trace elements were chosen for their potential toxic effects.Evolution of the pollution by trace elements into the marine environment further to the recent modifications of their production and use by men: case of the Western Mediterranean Se
O Charlent - One of the best experts on this subject based on the ideXlab platform.
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neutron activation analysis of elemental composition in a marine Phanerogam posidonia oceanica l delile a biological indicator of pollution
Environmental and Experimental Botany, 1991Co-Authors: A Grauby, H Augier, R Lion, O CharlentAbstract:Abstract Neutron activation analysis of samples of the marine Phanerogam Posidonia oceanica (L.) Delile, collected from a reference zone in Port-Cros National Park of the Mediterranean coast of France, detected 29 elements, bringing the total known elements in this plant to 43. Significant differences were found in the distribution of these elements in the leaves and flowers, as well as among the different types of leaves in the foliar bundle. The effect of pollution related to maritime activities was investigated by comparing samples from the reference zone with samples from a bay overcrowded with pleasure boats. Samples taken in the reference zone under the same conditions before and after the Chernobyl accident were compared to identify elements attributable to the nuclear power industry and in particular to that accident. The ability of Posidonia oceanica to concentrate elements from sea-water, notably those known for their biotoxicity, shows the advantage of using this plant as a biological indicator for this type of pollution. The data indicated that the reliability of the results obtained is closely dependent on the sampling methods, particularly when using a sensitive and high-resolution method such as neutron activation.
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neutron activation analysis of the elementary composition of the marine Phanerogam posidonia oceanica from a reference area in port cros national park french mediterranean
Marine Biology, 1991Co-Authors: H Augier, Claude Ronneau, P Roucoux, R Lion, O CharlentAbstract:The marine Phanerogam Posidonia oceanica (L.) Delile was collected from a presumably unpolluted "reference" area in Port Cros National Park, Mediterranean Sea, in November 1985, and its elemental composition was studied by gamma spectrometry after neutron activation and by atomic-absorption spectrophotometry. Neutron-activation analysis revealed 23 elements and atomic-absorption spectrophotometry 4 others. Including all known records by other investigators, this brings the total of elementary components identified in P. oceanica up to 42: antimony, arsenic, barium, bromine, cadmium, cesium, calcium, carbon, cerium, chromium, cobalt, copper, europium, gold, hafnium, hydrogen, iodine, iron, lanthanum, lead, magnesium, manganese, mercury, molybdenum, nickel, nitrogen, phosphorus, potassium, rubidium, samarium, scandium, selenium, silver. sodium, strontium, tantalum, terbium, thorium, uranium, ytterbium, zinc, zirconium. These elements display significant differences in their distribution in the various parts of the plant (roots, rhizomes, and growing and freshly budded leaves).
Richir Jonathan - One of the best experts on this subject based on the ideXlab platform.
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Récentes menaces de pollution par les éléments traces pesant sur l'écosystème côtier: une étude multiélémentaire
2009Co-Authors: Richir Jonathan, Gobert Sylvie, Bouquegneau Jean-marieAbstract:The Mediterranean Sea is an enclosed basin, highly submitted to anthropogenic pressures. Chemical pollution from coastal urban centres and industries, or carried by air and rivers, primarily affects its coastal ecosystems. Pollution by trace elements is rapidly evolving further to the recent modifications of their production and industrial uses by men. As a result, certain trace elements can now be considered as new environmental pollutants. Appropriate bioindicators are useful tools for the early warning of marine pollution. We presently investigate the use of the purple sea urchin Paracentrotus lividus and the marine Phanerogam Posidonia oceanica as bioindicators to monitor the Mediterranean coastal pollution by new trace pollutants (Be, V, Mo, Mn, PGEs, Ag, Al, As, Se, Sb and Bi). Classic trace metals (Cd, Cr, Cu, Zn, Ni, Sn, Pb, Co and Fe) are also studied. Organisms were seasonally collected in 2008 in a reference site and a polluted one, respectively Calvi bay (Corsica) and Marseille (France). Their tissular trace element concentrations were determined by ICP-MS. All the investigated trace elements were chosen for their potential toxic effects.Peer reviewe
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Récentes menaces de pollution par les éléments traces pesant sur l'écosystème côtier: une étude multiélémentaire
2009Co-Authors: Richir Jonathan, Gobert Sylvie, Bouquegneau Jean-marieAbstract:peer reviewedaudience: researcherThe Mediterranean Sea is an enclosed basin, highly submitted to anthropogenic pressures. Chemical pollution from coastal urban centres and industries, or carried by air and rivers, primarily affects its coastal ecosystems. Pollution by trace elements is rapidly evolving further to the recent modifications of their production and industrial uses by men. As a result, certain trace elements can now be considered as new environmental pollutants. Appropriate bioindicators are useful tools for the early warning of marine pollution. We presently investigate the use of the purple sea urchin Paracentrotus lividus and the marine Phanerogam Posidonia oceanica as bioindicators to monitor the Mediterranean coastal pollution by new trace pollutants (Be, V, Mo, Mn, PGEs, Ag, Al, As, Se, Sb and Bi). Classic trace metals (Cd, Cr, Cu, Zn, Ni, Sn, Pb, Co and Fe) are also studied. Organisms were seasonally collected in 2008 in a reference site and a polluted one, respectively Calvi bay (Corsica) and Marseille (France). Their tissular trace element concentrations were determined by ICP-MS. All the investigated trace elements were chosen for their potential toxic effects.Evolution of the pollution by trace elements into the marine environment further to the recent modifications of their production and use by men: case of the Western Mediterranean Se
Gerard Pergent - One of the best experts on this subject based on the ideXlab platform.
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the ecological importance of an invertebrate chemoautotrophic symbiosis to Phanerogam seagrass beds
Bulletin of Marine Science, 2002Co-Authors: Monique Johnson, Catherine Fernandez, Gerard PergentAbstract:The symbiotic chemoautotrophic bivalve Loripes lacteus was found to inhabit Cymodocea nodosa seagrass beds in a lagoon in Upper Corsica. Clams were observed at a mean density of 775 ind m −2 . Mean clam wet weight for the site was 0.099 mg and the gill, organ in which are found the sulfur-oxidizing endosymbiotic bacteria, accounted for 32.5% of total body weight. Total wet tissue weight due to these animals in this sediment was therefore in the order of 77 g m −2 . The percentage of carbon is 11.2% of wet weight. A rough estimate of net clam production within the seagrass bed yields a value of 1.73 g C m −2 yr −1 . The autotrophic potential of Loripes lacteus was calculated to be in the order of 47.2 g C m −2 yr −1 , which represents roughly 16% of the seagrass bed’s primary production. The role of these symbioses, in terms of carbon flux, within Phanerogam seagrass beds is discussed. Chemoautotrophic symbioses are nutritionally based associations between sulfur-oxidizing chemoautotrophic bacteria and marine invertebrate or protist hosts. Marine molluscs that contain symbiotic sulfur-oxidizing chemolithotrophic bacteria have been identified from a variety of sulfide-rich habitats, such as sewage outfall areas (Felbeck et al., 1981; Johnson et al., 1994), pulp mill effluent sites (Reid, 1980), anoxic basins (Felbeck et al., 1981), mangrove swamps (Schweimanns and Felbeck, 1985; Frenkiel et al., 1996), seagrass beds (Fisher and Hand, 1984), and hydrothermal vents (Cavanaugh, 1983). A common feature of these habitats is the simultaneous availability of hydrogen sulfide and molecular oxygen. This dissolved sulfide (HS − and H 2 S) provides the energy source used to drive the reductive bacterially-mediated reactions of carbon fixation (Childress and Mickel, 1982; Felbeck, 1983; Cavanaugh, 1983; Fisher, 1990). This sulfide can originate either from geothermal sources, such as at hydrothermal vents, or from decaying organic matter as, for example, in seagrass meadows. A large portion of the plant material produced in these latter habitats is eventually deposited on the bottom as detritus, leading to high organic content and high oxygen demand. As a result, the abundance of organic material in seagrass sediments is often greater than the oxygen available for its degradation, leading to an elevated activity of sulfate-reducing bacteria and the production of high levels of hydrogen sulfide (Jorgensen and Fenchel 1974). Indeed, Solemya velum (Solemyidae) has been reported from eelgrass beds that ‘smelled strongly’ of hydrogen sulfide (Cavanaugh, 1983), Codakia orbicularis (Lucinidae) occurs in beds of the seagrass Thalassia testudinum in zones of ‘high sulphide concentration’ (Berg and Alatolo, 1984) and decaying seagrass leaves leading to the production of sulfide are characteristic of the habitat of Lucina floridana (Lucinidae) (Fisher and Hand, 1984).
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effect of a newly set up wastewater treatment plant on a marine Phanerogam seagrass bed a medium term monitoring program
Bulletin of Marine Science, 2002Co-Authors: Christine Pergentmartini, Gerard Pergent, Vanina Pasqualini, Lila FerratAbstract:Although the impact of declining environmental conditions on marine Phanerogam seagrass beds has been well documented, the reverse phenomenon, notably the natural recolonization of seagrass beds following an improvement in water quality, has received very little attention. In light of this, and following the establishment, in 1987, of wastewater-treatment plant in the city of Marseilles (Mediterranean, France), the bottom cover and vitality of a Posidonia oceanica seagrass bed was followed closely. The objectives of this study were to understand the development of these plants, which are true indications of water quality, by monitoring a number of parameters (e.g., location of the seagrass bed, density, leaf biometry). The results reveal that there has been an overall improvement in the vitality of the P. oceanica seagrass beds since 1987. Thus, natural recolonization phenomena are occurring and would seem to indicate that the seagrass beds are able to respond positively, in the medium term, to reductions in anthropogenic impacts.
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mapping ofposidonia oceanicausing aerial photographs and side scan sonar application off the island of corsica france
Estuarine Coastal and Shelf Science, 1998Co-Authors: Vanina Pasqualini, C Pergentmartini, Philippe Clabaut, Gerard PergentAbstract:In light of the essential role that seagrass beds play from an ecological and sedimentary point of view, mapping of these organisms should be carried out in order to clearly assess their distribution. Although a large number seagrass beds have been mapped, these generally only take into consideration the shallower formations (0–15 m) or those which are geographically very confined (<5000 ha) due to the inherent difficulties involved in mapping such ecosystems. Posidonia oceanicais a marine Phanerogam endemic to the Mediterranean. The wide bathymetric range (0–50 m) of this species increases the difficulties involved in its mapping. The combined use of image processing of aerial photographs for the shallower layers (0–15 or 20 m in regions of very sheltered waters) and of side scan sonar for the deeper depths (20–50 m) is a particularly suitable approach. The implementation of these techniques along the Corsican coast (approximately 127 000 ha) allowed the mapping of assemblages and bottom-types present from the surface to a depth of 50 m with a resolution of 5 m. The results reveal thatP. oceanicaseagrass beds occupy a surface area of approximately 62 000 ha with a mean lower bathymetric limit of about 32 m. A comparison of these results with other regions of the Mediterranean confirms the extent of distribution of this species along the Corsican coast (49·1% from 0 to 50 mvs16·3% along the French continental coast). The surface area of the Mediterranean coastline potentially occupied byP. oceanicaseagrass beds can be estimated to be between 2·5 and 5 million hectares.
Margherita Gavagnin - One of the best experts on this subject based on the ideXlab platform.
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prenylated flavonoids and phenolic compounds from the rhizomes of marine Phanerogam cymodocea nodosa
Planta Medica, 2017Co-Authors: Abla Smadi, Fatma Bitam, Maria Letizia Ciavatta, Guido Villani, Marianna Carbone, Margherita GavagninAbstract:Chemical investigation of the rhizomes of the marine Phanerogam Cymodocea nodosa resulted in the isolation of two new prenylated flavon-di-O-glycosides, cymodioside A (1) and B (2), along with known phenolic compounds 3–7, some of which never reported from seagrasses to date. The structures of compounds 1 and 2 were established by extensive nuclear magnetic resonance analysis. In addition, the absolute configuration of 4-(2,5-dihydroxyhexyl) benzene-1,2-diol (7), which was not previously reported in the literature, has been now determined.
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The first record of neolignans from the marine Phanerogam Posidonia oceanica
Phytochemistry Letters, 2012Co-Authors: Fatma Bitam, Maria Letizia Ciavatta, Emiliano Manzo, Guido Villani, Margherita GavagninAbstract:Abstract Chemical analysis of the secondary metabolites of Posidonia oceanica rhizomes led to the identification of several compounds. In particular, two neolignans, co-occurring with related metabolites previously described from the plant kingdom, have been isolated and characterised by spectroscopic methods. To the best of our knowledge, this is the first report of neolignans from a marine Phanerogam.