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| Registros recuperados: 16 | |
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| De Wit, Rutger; Leruste, Amandine; Le Fur, Ines; Maki Sy, Mariam; Bec, Beatrice; Ouisse, Vincent; Derolez, Valerie; Rey-valette, Hélène. |
| By the end of the 20th century, many of the coastal lagoons along the French Mediterranean coast showed insufficient water quality and degraded ecosystem states due to anthropogenic impacts. Among these, nutrient over-enrichment, resulting in eutrophication, has been a major concern. The EU Water Framework Directive (WFD) has initiated public action to improve their water quality and ecosystem state using an approach rooted in restoration ecology. Here we analyze how this has been applied for the coastal lagoons in South France, considering eutrophication as an example of ecosystem degradation and oligotrophication as the corresponding trajectory for ecological restoration of the eutrophied coastal lagoons. Oligotrophication trajectories, initiated by the... |
| Tipo: Text |
Palavras-chave: Restoration ecology; Ecological restoration; Water quality; WFD; Ecosystem trajectories; DPSIR; Conservation; Ecological indices. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00629/74145/73683.pdf |
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| Audouit, Christelle; Pasqualini, Vanina; De Wit, Rutger; Flanquart, Herve; Deboudt, Philippe; Rufin-soler, Caroline. |
| Coastal lagoons are important for coastal and marine biodiversity. Nevertheless, they are very sensitive and vulnerable to human impacts, which often result in a decrease of their biodiversity and degradation of their water quality. Considering recent efforts for ecological restoration of coastal lagoons, it appears appropriate to compare the social representations of users of the coastal lagoons and of inhabitants, with ecological diagnoses of biodiversity and water quality. The main question is whether there is congruence between water quality defined by environmental criteria on one hand and the social representations of these issues by lagoon users and local populations on the other hand? How can we explain the social representations of lagoons... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00486/59793/63012.pdf |
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| De Wit, Rutger; Troussellier, Marc; Courties, Claude; Buffan-dubau, Evelyne; Lemaire, Emmanuelle. |
| We experimentally simulated the temporality of the interactions between intertidal seagrasses and phytoplankton in the context of nutrient enrichment from continental origin. Phytoplankton development was retarded after 1-day exposure to intertidal Zostera noltii Hornemann vegetation samples, with respect to control treatments. This was not explained by resource competition and we hypothesized a direct interference between seagrass leaves and phytoplankton. After separation from the vegetation in 5-day incubations, the final yield of large phytoplankton, mainly diatoms and haptophytes, was determined by nutrient loading. In contrast, Synechococcus-like cells (SYN), phototrophic picoeukaryotes and nanophytoplankton decreased after day 3, most likely due to... |
| Tipo: Text |
Palavras-chave: Competition; Allelopathy; Zostera noltii; Sediment; Intertidal vegetation; Flow cytometry; Photosynthetic pigments. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00106/21717/19414.pdf |
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| De Wit, Rutger; Vincent, Alice; Foulc, Ludovic; Klesczewski, Mario; Scher, Olivier; Loste, Claudine; Thibault, Marc; Poulin, Brigitte; Ernoul, Lisa; Boutron, Olivier. |
| After World War II, twenty-nine coastal Salinas (122 km2), located in the vicinity of coastal lagoons and in deltas, were exploited along the Mediterranean coastlines in South France. Today, only five of these are still actively producing salt, currently representing 175 km2. Concomitant with the abandonment of many of the smaller Salinas, the larger Salinas in the Rhône delta (Camargue) strongly increased their surfaces at the expense of natural ecosystems, of which a part has also been abandoned after 2009. This paper documents these changes in landscape use by chronological GIS mapping and describes the fate of the 91 km2 of abandoned Salina surfaces. The majority of this area (88 km2) is included in the Natura 2000 network, among which most (74 km2)... |
| Tipo: Text |
Palavras-chave: Corine land cover 4.2.2; Microbial mats; Waterfowl; Halophytes; Coastal lagoon; Delta. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00486/59748/62853.pdf |
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| Zilius, Mindaugas; De Wit, Rutger; Bartoli, Marco. |
| Sedimentation of pelagic cyanobacteria in dystrophic freshwater and oligohaline lagoons results in large inputs of labile organic matter (OM) to the benthos. We used an experimental approach to study the short-term impact of such phenomena on the benthic microbial community metabolism and on the nitrogen (N) fluxes across the sediment-water interface. We hypothesized an increase of respiratory activity, including N loss via denitrification and its recycling to the water column. Our results show that the incorporation within sediments of the settled bloom increases benthic bacterial activities. This is coupled to large DON and NH4+ effluxes, and to a comparatively smaller increase of N-2 production, while no significant effects were detected for the benthic... |
| Tipo: Text |
Palavras-chave: Cyanobacteria; Organic matter; Sediments; Benthic metabolism; DON; Denitrification. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00354/46504/74457.pdf |
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| Rossi, Francesca; Colao, Elodie; Jose Martinez, Maria; Klein, Judith C.; Carcaillet, Frederique; Callier, Myriam; De Wit, Rutger; Caro, Audrey. |
| Sulphur-oxidising endosymbiont-bearing bivalves often inhabit seagrass meadows, where they can control sulphide levels and variably contribute to carbon cycling, by feeding on endosymbiotic bacteria and/or on particulate organic matter from the water column. The patterns of variability in their feeding mode and their spatial distribution within the seagrass meadows are however poorly studied. Seagrass beds form naturally patchy habitats with seagrass-sand edges that may have variable effects on different organisms. The present study aims at understanding differences in feeding mode and abundance of the endosymbiont-bearing bivalve Loripes lacteus (sensu Poli, 1791) as well as the physiological conditions of its endosymbiotic populations between edge and... |
| Tipo: Text |
Palavras-chave: Bivalve; Food web; Mediterranean; Seagrass; Stable isotopes; Symbiosis. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00138/24911/26373.pdf |
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| Le Fur, Ines; De Wit, Rutger; Plus, Martin; Oheix, Jocelyne; Derolez, Valerie; Simier, Monique; Malet, Nathalie; Ouisse, Vincent. |
| Since the mid-20th century, Mediterranean lagoons have been affected by eutrophication, leading to significant changes in primary producers. In the early 2000s, management actions have been implemented to reduce nutrient inputs with the aim to achieve a good ecological status as requested by the EU water framework directive. As a result of these actions, a sharp decline in nutrient loads has been recorded in several lagoons leading to an oligotrophication of the water column. The analyses of a long-term data set (1998-2015) of 21 polyhaline and euhaline lagoons with contrasting trophic status allowed us to infer a general scheme for the changes in macrophyte assemblages during the oligotrophication process. Placing hypertrophic and oligotrophic conditions... |
| Tipo: Text |
Palavras-chave: Submerged aquatic vegetation; Recovery; Nutrient reduction; Restoration; Long-term data series; Resilience; Regime shift; Coastal lagoon. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00474/58555/61110.pdf |
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| De Wit, Rutger; Leibreich, J; Vernier, F; Delmas, F; Beuffe, H; Maison, P; Chossat, J; Laplace Treyture, C; Laplana, R; Clave, V; Torre, M; Auby, Isabelle; Trut, Gilles; Maurer, Daniele; Capdeville, P. |
| Nitrogen loading to the Bassin d'Arcachon coastal lagoon (SW France) was evaluated by studying land-use and nitrogen output in its 3001 km(2) catchment. At present, the catchment is dominated by forestry (79%), while intensive agriculture occupies 9% of the surface. The N-output of two hydrological subunits, i.e. the Tagon subunit dominated by pine forestry and the Arriou 11 subunit comprising both forestry and intensive agriculture, were monitored for a seven year period (1996-2002). From these observations it was calculated that forestry contributes on average 1.6 kg total N ha(-1) yr(-1), which is dominated by organic nitrogen (DON+PON are 70% of N). On an areal basis, intensive agriculture contributes 26 times more than forestry, i.e. 41.6 kg total N... |
| Tipo: Text |
Palavras-chave: Macroalgae; Seagrasses; Nitrogen loading; Catchment. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-757.pdf |
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| Ouisse, Vincent; Fiandrino, Annie; Malet, Nathalie; Munaron, Dominique; Fortune, Martine; Oheix, Jocelyne; Baleux, Maeva; Lagarde, Franck; Le Noc, Sandrine; De Wit, Rutger. |
| Increased nitrogen and phosphorus inputs from watersheds, especially since the 1960s with the increased anthropogenic activities is recognized as a major cause of environmental degradation of coastal ecosystems. On the Mediterranean coast, lagoons are particularly affected by the eutrophication leading to significant changes in ecosystem structure, functioning and services. Since 2000, the “Région Languedoc-Roussillon”, the “Agence de l’Eau Rhône Mediterranée & Corse” and Ifremer developed a lagoon monitoring network (RSL) focusses upon eutrophication to assess and monitor status of 24 lagoons of Languedoc-Roussillon and Corsica. Many actions on watershed led to a significant reduction of nutrient inputs. However, the time required to restore these... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00118/22899/20717.pdf |
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| Hickman-lewis, Keyron; Gautret, Pascale; Arbaret, Laurent; Sorieul, Stéphanie; De Wit, Rutger; Foucher, Frédéric; Cavalazzi, Barbara; Westall, Frances. |
| Morphologically diverse organo-sedimentary structures (including microbial mats and stromatolites) provide a palaeobiological record through more than three billion years of Earth history. Since understanding much of the Archaean fossil record is contingent upon proving the biogenicity of such structures, mechanistic interpretations of well-preserved fossil microbialites can reinforce our understanding of their biogeochemistry and distinguish unambiguous biological characteristics in these structures, which represent some of the earliest records of life. Mechanistic morphogenetic understanding relies upon the analysis of geomicrobiological experiments. Herein, we report morphological-biogeochemical comparisons between micromorphologies observed in growth... |
| Tipo: Text |
Palavras-chave: Microbial mat; Stromatolite; Anoxygenic photosynthesis; X-ray micro-scale computed tomography; Archaean; Early life; Dresser Formation; Middle Marker horizon. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00512/62323/66580.pdf |
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| Registros recuperados: 16 | |
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