Consulta: creatorFacets:"De Wit, Rutger"
Registros recuperados: 16
Data/hora: 01/06/2024 09:44:37

Re-oligotrophication trajectories of macrophyte assemblages in Mediterranean coastal lagoons based on 17-year time-series
Provedor de dados: 5
Autores: 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

How to elaborate integrated management of transitional water ? Assessment of the reference state in Biguglia lagoon (Corsica, france)
Provedor de dados: 5
Autores: Garrido, Marie; Cecchi, Philippe; Malet, Nathalie; De Wit, Rutger; Pasqualini, Vanina.
Tipo: Text
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00341/45211/44633.pdf

Response of sedimentary processes to cyanobacteria loading
Provedor de dados: 5
Autores: 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

Short-term interactions between phytoplankton and intertidal seagrass vegetation in a coastal lagoon (Bassin d'Arcachon, SW France)
Provedor de dados: 5
Autores: 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

A Multidisciplinary Approach for Restoration Ecology of Shallow Coastal Lagoons, a Case Study in South France
Provedor de dados: 5
Autores: 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

First Field-Based Evidence That the Seagrass-Lucinid Mutualism Can Mitigate Sulfide Stress in Seagrasses
Provedor de dados: 5
Autores: Van Der Geest, Matthijs; Van Der Heide, Tjisse; Holmer, Marianne; De Wit, Rutger.
Seagrass meadows form vital ecological components of coastal zones worldwide, but are rapidly declining. Large-scale seagrass diebacks have been related to accumulation of toxic sulfide in the sediment, a phenomenon predicted to occur more frequently in the near future due to ongoing global warming and increasing organic loading of coastal systems worldwide. Recently, a facultative mutualism between seagrasses and lucinid bivalves with endosymbiotic sulfide-consuming gill bacteria was discovered that may prevent toxic sulfide accumulation in seagrass sediments. Yet, direct field-based evidence for the importance of this mutualism in alleviating sulfide stress in seagrasses is currently lacking, as well as how its role may change when sediment sulfide...
Tipo: Text
Palavras-chave: Delta S-34; Seagrass performance; Environmental change; Sediment sulfide stress; Seagrass-lucinid mutualism; Lucinid bivalves; Mutualistic interactions.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00609/72073/70782.pdf

Restoration ecology of coastal lagoons: new methods for the prediction of ecological trajectories and economic valuation
Provedor de dados: 5
Autores: De Wit, Rutger; Rey-valette, Helene; Balavoine, Juliette; Ouisse, Vincent; Lifran, Robert.
Conservation of the seven lagoons of the Palavas complex (southern France) has been severely impaired by nutrient over-enrichment during at least four decades. The effluents of the Montpellier wastewater treatment plant (WWTP) represented the main nutrient input. To improve the water quality of these lagoons, this WWTP was renovated and upgraded and, since the end of 2005, its effluents have been discharged 11 km offshore into the Mediterranean (total investment €150 M).   Possibilities of ecosystem restoration as part of a conservation programme were explored by a focus group of experts. Their tasks were: (i) to evaluate the impact of the reduction of the nutrient input; (ii) if necessary, to design additional measures for an active restoration programme;...
Tipo: Text
Palavras-chave: Coastal lagoon; Seagrass meadow; Marine and brackish Magnoliophyta; Phytoplankton; Ecosystem services; Willingness to pay (WTP); Ecosystem trajectory' nutrient enrichment; Oligotrophication; Sediment N and P contents; Water Framework Directive.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00317/42867/42368.pdf

Restauration des écosystèmes lagunaires : évaluation du rôle du sédiment et des herbiers à phanérogames
Provedor de dados: 5
Autores: Ouisse, Vincent; Fiandrino, Annie; De Wit, Rutger; Malet, Nathalie.
Les politiques publiques mises en place pour la reconquête de la bonne qualité des écosystèmes lagunaires se sont attachées à réduire les intrants d’éléments nutritifs (N et P). Cependant, au cours des 30 dernières années, les lagunes ont stocké d’importantes quantités de ces éléments, notamment dans les sédiments. Par conséquent, ce stock sédimentaire est de nature à freiner la restauration des milieux lagunaires (hystérésis) et à retarder l’atteinte du bon état écologique (Directive Cadre sur l’Eau). Six stations réparties le long du gradient d’eutrophisation des lagunes méditerranéennes ont été suivies en avril, juillet et novembre 2012 afin d’estimer les flux biogéochimiques à l’interface entre le compartiment benthique et la colonne d’eau. Les...
Tipo: Text
Palavras-chave: Restauration des milieux lagunaires; Eutrophisation; Flux biogéochimiques; Azote; Phosphore; Herbier; Sédiment.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00166/27774/25964.pdf

Mechanistic Morphogenesis of Organo-Sedimentary Structures Growing Under Geochemically Stressed Conditions: Keystone to Proving the Biogenicity of Some Archaean Stromatolites?
Provedor de dados: 5
Autores: 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

Malaïgue 2018 sur la lagune de Thau – Demande d’informations complémentaires
Provedor de dados: 5
Autores: Richard, Marion; De Wit, Rutger; Fiandrino, Annie.
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00466/57777/79197.pdf

Seventy-year chronology of Salinas in southern France: coastal surfaces managed for salt production and conservation issues for abandoned sites
Provedor de dados: 5
Autores: 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

Phosphorus and nitrogen future in eutrophised mediterranean lagoons
Provedor de dados: 5
Autores: 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 &amp; 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
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00118/22899/20717.pdf

Relationship between land-use in the agro-forestry system of les Landes, nitrogen loading to and risk of macro-algal blooming in the Bassin d'Arcachon coastal lagoon (SW France)
Provedor de dados: 5
Autores: 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

Spatial distribution and nutritional requirements of the endosymbiont-bearing bivalve Loripes lacteus (sensu Poli, 1791) in a Mediterranean Nanozostera noltii (Hornemann) meadow
Provedor de dados: 5
Autores: 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

Comparing social representation of water quality in coastal lagoons with normative use of ecological indicators
Provedor de dados: 5
Autores: 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
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00486/59793/63012.pdf

Vulnerability of intertropical littoral areas
Provedor de dados: 5
Autores: Manighetti, Isabelle; De Wit, Rutger; Duvail, Stephanie; Seyler, Patrick.
Tipo: Text
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00417/52851/74873.pdf