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An underwater tracking system for mapping marine communities: an application to Posidonia oceanica ArchiMer
Sgorbini, S; Peirano, A; Cocito, S; Morgigni, M.
The GPS intelligent buoy is a pot-table underwater tracking system consisting of four buoys and one pinger. The pinger was mounted on an underwater vehicle driven by a Scuba diver and used to map the limits of a Posidonia oceanica meadow. To test the accuracy of the method the system was tried out on different types of limits and on healthy and regressed part of the meadow from 2 to 25 m of depth. The time of track acquisition (1 point per second), the recording speed (1 km h(-1)) and the mapping scale (more than 1:500) indicated that the proposed method may be successfully integrated with conventional systems for mapping marine communities. (C) 2002 Ifremer/CNRS/IRD/Editions scientifiques et medicales Elsevier SAS. All rights reserved.
Tipo: Text Palavras-chave: Cartographie; Phanérogames marines; Posidonia oceanica; Méditerranée; Mapping; Seagass; Posidonia oceanica; Mediterranean Sea.
Ano: 2002 URL: http://archimer.ifremer.fr/doc/00322/43314/42940.pdf
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Assessment and quantification of the anthropic impact on the posidonia oceanica seagrass meadow ArchiMer
Alami, Sami; Bonacorsi, Marina; Clabaut, Philippe; Jouet, Gwenael; Pergent-martini, Christine; Pergent, Gerard; Sterckeman, Aurore.
The regression of seagrass meadows has been extensively studied over the past few years. Although the causes of this regression may be locally natural, it is more generally related to human impact. In the framework of the HalGolo (2010) and CoralCorse (2013) oceanographic campaigns, acoustic data (mosaic of sonograms and bathymetry), validated by field data (Scuba diving, ROV), were acquired at depths of -10 m and -50 m at the NATURA 2000 site “Grand Herbier de la Plaine Orientale” (Western Mediterranean, Corsica). Processing of this data provided evidence of the scale of this mechanical degradation (trawling scars, mooring, etc.), and enabled its quantification with regard to surface area and scar density. The main degradation was observed between -20 and...
Tipo: Text Palavras-chave: Anthropogenic impact; Corsica; Side Scan Sonar; Posidonia oceanica; Trawling.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00272/38364/36669.pdf
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Assessment of the ecological status of Mediterranean French coastal waters as required by the Water Framework Directive using the Posidonia oceanica Rapid Easy Index: PREI ArchiMer
Gobert, Sylvie; Sartoretto, Stephane; Rico-raimondino, Valerie; Andral, Bruno; Chery, Aurelia; Lejeune, Pierre; Boissery, Pierre.
This paper describes the PREI (Posidonia oceanica Rapid Easy Index), a method used to assess the ecological status of seawater along Mediterranean French coasts. The PREI was drawn up according to the requirements of the Water Framework Directive (WFD 2000/60/EC) and was tested on 24 and 18 stations in PACA (Provence-Alpes-Cotes d'Azur) and Corsica, respectively. The PREI is based on five metrics: shoot density, shoot leaf surface area, E/L ratio (epiphytic biomass/leaf biomass), depth of lower limit, and type of this lower limit. The 42 studied stations were classified in the first four levels of status: high, good, moderate and poor. The PREI values ranged between 0.280 and 0.847; this classification is in accordance with our field knowledge and with our...
Tipo: Text Palavras-chave: Water Frame Directive; Ecological Quality Ratio; Coastal water; Mediterranean Sea; Posidonia oceanica; Seagrass.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6949.pdf
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Biomass distribution and physiological capabilities of bacteria in the water column above a sea grass system. ArchiMer
Velimirov, B; Herndl, G; Kavka, G.
The distribution pattern of bacteria in the water column above and within a Posidonia oceanica bed near Ischia (off the Gulf of Naples) was investigated and correlated with DOC and POM data for autumn and winter. Data from samples of 5 stations along a transect from shallow to deep showed rather low bacterial densities (10 super(4).ml super(-1)) for both seasons. The number of attached bacteria was higher in late winter as compared to autumn when the leaves are shed from the stands. Except for occasional peaks DOC ranged between 1.5 and 4.5 mg C/1 while POM concentrations ranged form 4 to 14 mg AFDW.1 super(-1). Hydrolytic capabilities of isolated bacterial colonies showed that more carbohydrate substrates could be fermented in winter as compared to...
Tipo: Text Palavras-chave: Posidonia oceanica; Microorganisms; Physiology; Seasonal distribution; Algae; Bacteria; Particulate organic matter; Metabolism; Water column; Fermentation; Sea grass.
Ano: 1984 URL: http://archimer.ifremer.fr/doc/1984/acte-954.pdf
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Comparative Analysis of Stability-Genetic Diversity in Seagrass (Posidonia oceanica) Meadows Yields Unexpected Results ArchiMer
Arnaud-haond, Sophie; Marba, Nuria; Diaz-almela, Elena; Serrao, Ester A.; Duarte, Carlos M..
The diversity-stability relationship is the subject of a long-standing debate in ecology, but the genetic component of diversity has seldom been explored. In this study, we analyzed the interplay between genetic diversity and demographic responses to environmental pressures. This analysis included 30 meadows formed by the Mediterranean endemic seagrass, Posidonia oceanica, showing a wide range of population dynamics ranging from a near equilibrium state to steep decline due to strong environmental pressures close to aquaculture installations. Our results show that sedimentation rates are much better predictors of mortality than clonal or genetic components. An unexpected positive trend was observed between genotypic diversity and mortality, along with a...
Tipo: Text Palavras-chave: Seagrass; Demography; Clonality; Genetic richness; Diversity-stability; Posidonia oceanica.
Ano: 2010 URL: http://archimer.ifremer.fr/doc/00006/11693/8498.pdf
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Effects of fish farming on seagrass (Posidonia oceanica) in a Mediterranean bay: seagrass decline after organic loading cessation ArchiMer
Delgado, O; Ruiz, J; Perez, M; Romero, J; Ballesteros, E.
The effects of fish farming on a seagrass (Posidonia oceanica) meadow at Fornells Bay, Minorca (Balearic Islands) were studied. Changes in plant and meadow features (e.g. shoot morphology, shoot density, biomass, rhizome growth, nutrient and soluble sugars concentrations...) in three stations along a transect from a disturbed (organic pollution due to fish cultures) to an undisturbed site were assessed. The fish culture had ceased in 1991; however, seagrass decline, already reported in a previous study for the period 1988-1990, was still taking place at the time of sampling (July 1994). Differences between stations were very clear; the station closest to the fish cages showed reduced shoot density, shoot size, underground biomass, sucrose concentration and...
Tipo: Text Palavras-chave: Aquaculture; Phanérogame marine; Posidonia oceanica; Eutrophisation; Caractéristique du sédiment; Aquaculture; Seagrass; Posidonia oceanica; Eutrophication; Sediment characteristics.
Ano: 1999 URL: http://archimer.ifremer.fr/doc/00325/43632/43250.pdf
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Mapping of Posidonia oceanica beds around Elba Island (western Mediterranean) with integration of direct and indirect methods ArchiMer
Piazzi, L; Acunto, S; Cinelli, F.
Direct and indirect methods were used for mapping Posidonia oceanica beds around Elba Island. Side scan sonar and a visual infra red scanner were used to detect the extension of beds. Also, direct observations were adopted to assess the bed density and to calibrate the indirect methods. Samples of P. oceanica were collected and phenological variables and macroalgal epiphytes were studied to assess the health of the beds. P. oceanica around Elba Island covered an area of 3 680 ha. The largest beds occupied the four main gulfs of the island, characterized by gentle slopes and sandy bottoms. There, the beds showed uniform cover while a patchy structure was common on the rocky and steep bottoms of the western and south-eastern coasts of the island. P. oceanica...
Tipo: Text Palavras-chave: Posidonia oceanica; Algues; Cartographie; Sonar latéral; Télédétection aérienne; Méditerranée; Posidonia oceanica; Seagrass; Algae; Mapping; Airborne teledetection; Mediterranean.
Ano: 2000 URL: http://archimer.ifremer.fr/doc/00324/43567/44064.pdf
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Organic and inorganic human-induced contamination of Posidonia oceanica meadows ArchiMer
Pergent, Gerard; Labbe, Celine; Lafabrie, Celine; Kantin, Roger; Pergent-martini, Christine.
In coastal environments, plants are used for phytoremediation of contamination. Organic and inorganic contaminants may be due to natural and/or anthropogenic sources. The aim of this study is to compare inorganic (trace metal) and organic (PAH) contamination in Posidonia oceanica and to analyse the relationship between these types of pollutants indeed very few studies have been interested in their correlations and common sources. P. oceanica leaves were collected in two sites exhibiting different levels of human-induced pressure. Higher values were recorded in the more polluted site (Toulon) for trace metals (Ag, Hg, Pb) as well as for PAHs (Medium Molecular Weight and High Molecular Weight) due to the presence of the city and/or harbour in proximity. For...
Tipo: Text Palavras-chave: Trace metals; Polycyclic aromatic hydrocarbons; Contamination; Seagrass; Posidonia oceanica; Mediterranean.
Ano: 2011 URL: http://archimer.ifremer.fr/doc/00038/14913/15671.pdf
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Posidonia oceanica L. (Delile) Meadow from Messioua OceanDocs
Sammari, Ch.; Hattour, A.; Komatsu, T.; Zarrouk, S; Ben Mustapha, K.; El Abed, A..
In order to study the benthic ecology of the “Messioua banc” (30 NM east off Zarzis, Southern Tunisia), a traditional Tunisian sponge fishing ground, four marine campaigns were conducted with the R/V “Hannibal” from October 2000 to August 2001. The objectives of three of these campaigns were field validation, focusing on the sampling of the Posidonia oceanica meadow and of the sponge population. However the goal of the fourth one, with the use of a multi-beam sonar SEABAT 9001 (Reson Co.), was the mapping of bottom of the surveyed area and the scanning of the Posidonia meadow and its sponge population. The field work allowed the study of sixteen stations covered by a dense meadow extending from 21 to 33 m depth, which present the highest density of...
Tipo: Journal Contribution Palavras-chave: Shoot density; Sponges; Posidonia oceanica; Http://aims.fao.org/aos/agrovoc/c_49750.
Ano: 2002 URL: http://hdl.handle.net/1834/226
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Preliminary data on the impact of fish farming facilities on Posidonia oceanica meadows in the Mediterranean ArchiMer
Pergent, G; Mendez, S; Pergent-martini, C; Pasqualini, V.
While the extension of aquaculture along the coasts of the Mediterranean islands is today an economic priority, no data is available on the impact of these facilities on the littoral environment in general, and in particular on the Posidonia oceanica meadows that are responsible for the richness and diversity of these biotopes. The impact of fish farming facilities in the marine littoral environment is assessed at three Mediterranean sites in Corsica and Sardinia. Various parameters are considered: (i) the amount of light available, (ii) the nature of the sediment, and (iii) the vitality of the Posidonia oceanica beds. The findings confirm the impact of the aquaculture facilities within the water column (increase in turbidity, enrichment of the sediment in...
Tipo: Text Palavras-chave: Aquaculture; Environnement; Phanérogames marines; Posidonia oceanica; Méditerranée; Aquaculture; Environment; Seagrass; Posidonia oceanica; Mediterranean.
Ano: 1999 URL: http://archimer.ifremer.fr/doc/00325/43631/43251.pdf
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Seasonal dependence on seagrass detritus and trophic niche partitioning in four copepod eco-morphotypes ArchiMer
Mascart, Thibaud; De Troch, Marleen; Remy, François; Michel, Loic; Lepoint, Gilles.
Benthic copepods dominate meiofaunal communities from marine phytodetritus, both in terms of numerical abundance and species diversity. Nevertheless, ecological factors driving copepod co-existence and population dynamics are still largely unknown. Here, we aimed to explore feeding habits of four copepod species commonly found in Mediterranean seagrass detritus accumulations, representing distinct eco-morphotypes (planktonic, phytal, epibenthic and mesopsammic). Joint use of fatty acid and stable isotope trophic markers showed that co-occurring harpacticoid copepods have diversified diets. Contrary to what was expected, microphytobenthos does not serve as their main food source. Instead, we found evidence from both techniques that major food items include...
Tipo: Text Palavras-chave: Macrophytodetritus; Posidonia oceanica; Meiofauna; Stable isotopes; Fatty acids; Isotopic niche; Mixing models; Mediterranean Sea.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00440/55187/60472.pdf
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Tunisian mega benthos from Infra (Posidonia meadows) and circalittoral (Coralligenous) sites OceanDocs
Ben Mustapha, K.; El Abed, A.; Komatsu, T.; Souissi, A.; Sammari, Ch.; Zarrouk, S; Hattour, A..
Several marine campaigns aiming to collect marine demosponges for specific research projects on their taxonomy and biogeography and to study the phenology and distribution of Posidonia oceanica a long the Tunisian coasts were conducted these last 10 years. They allowed a scuba diving prospecting of the infra and circalittoral zones of 555 marine stations. This field work was an occasion to describe some bottom’s associations, to highlight the general state of the main communities, specially the Posidonia and the coralligenous formations, and to draw up a list of their mega benthic species. In general, both biota are well preserved along the Tunisian coasts. except for some black spots, mainly the one of the gulf of Gabes, where detailed analysis showed...
Tipo: Journal Contribution Palavras-chave: Eponges; Ascidians; Coralligenous; Posidonia oceanica; Bryozoans; Benthos; Sponges.
Ano: 2002 URL: http://hdl.handle.net/1834/222
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Utilisation de Posidonia oceanica (L.) Delile comme bio-indicateur de la contamination métallique ArchiMer
Lafabrie, Céline.
The coastal zone of the continental shelf contains a high ecological richness. However, this zone is very fragile towards xenobiotics ; the pollution of this environment can be damaging to the structure of the biocenoses and to the productivity of the ecosystems. Metals, contrarily to numerous contaminants, are normal constituents of the environment at a trace level, but are all toxic above a certain threshold. At the end of the 1970s, several researchers proposed the use of organisms to evaluate the quality of the marine environment ; it is in this context that the bio-indicator concept arises. The seagrass Posidonia oceanica (L.) Delile, endemic of the Mediterranean Sea, has been the subject of several works proposing to use this species to determine the...
Tipo: Text Palavras-chave: Mediterranean Sea; Human impacts; Metal contamination; Trace metals; Bio indicator; Posidonia oceanica; Méditerranée; Impacts anthropiques; Contamination métallique; Métaux traces; Bio indicateur; Posidonia oceanica.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/these-3082.pdf
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Variations à différentes échelles spatiales de l'herbier à Posidonia oceanica (L.) Delile ; effets sur les paramètres physico-chimiques du sédiment ArchiMer
Gobert, S; Kyramarios, M; Lepoint, G; Pergent-martini, C; Bouquegneau, Jm.
The biometric parameters (shoot density, length and width of leaves, leaf and epiphyte biomasses, leaf surface) of the P. oceanica meadow present a significant spatial variability at the mesoscale level (100m(2)). All the parameters studied, excepting the number of leaves, decrease according to the depth. The horizontal spatial variations (centrifuge and centripetal distributions) reach a maximum in the shallower areas. The analysis of the microstructures (m(2)) of the meadow has not allowed a relationship to be established between the spatial variations of the biometric parameters and the environmental factors in the sediment (pH, water and organic matter content, red-ox potential, nutrient content). The heterogeneity of the meadow in the Revellata Bay...
Tipo: Text Palavras-chave: Posidonia oceanica; Distribution spatiale; Biomasse; Sédiment; Phanérogame; Méditerranée; Posidonia oceanica; Spatial distribution; Biomass; Sediment; Seagrass; Mediterranean Sea.
Ano: 2003 URL: http://archimer.ifremer.fr/doc/00322/43277/43009.pdf
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