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| Registros recuperados: 19 | |
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| Pete, Romain; Guyondet, Thomas; Bec, Beatrice; Derolez, Valerie; Cesmat, Ludovic; Lagarde, Franck; Pouvreau, Stephane; Fiandrino, Annie; Richard, Marion. |
| The decrease of microbial and nutrient inputs from the watershed has long dominated lagoon ecosystem management objectives. Phytoplankton biomass and abundance have drastically decreased for more than a decade and Zostera meadow have gradually recovered, expressing lagoon ecosystem restoration such as Thau lagoon. Do the progressive achievement of the good ecological status of the Thau lagoon possibly threatens the shellfish industry in terms of production and oyster quality, by reducing the carrying capacity? To provide answers about the right balance to be achieved between conservation and exploitation, a new numerical tool was developed to help in decision-making. We hereby propose to incorporate a Dynamic Energy Budget type shellfish production model... |
| Tipo: Text |
Palavras-chave: Shellfish farming; Carrying capacity; Stakeholder implication; Nitrogen and phosphorus inputs; Water frame directive; Ecological indicators; Phytoplankton depletion; Coupled biogeochemical-deb model. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00622/73395/75312.pdf |
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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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| Richard, Marion; Bec, Beatrice; Vanhuysse, Charles; Mas, Sébastien; Parin, David; Chantalat, Camila; Le Gall, Patrik; Fiandrino, Annie; Lagarde, Franck; Mortreux, Serge; Ouisse, Vincent; Rolland, Jean-luc; Degut, Anaïs; Hatey, Elise; Fortune, Martine; Roque D'Orbcastel, Emmanuelle; Messiaen, Gregory; Munaron, Dominique; Callier, Myriam; Oheix, Jocelyne; Derolez, Valerie; Mostajir, Behzad. |
| Oysters modify the planktonic microbial community structure by their filtration and NH4 excretion activities. While many studies have been conducted on this subject with adult oysters, none had been carried out in situ with juveniles. Pacific oyster juveniles (Magallana gigas, previously Crassostrea gigas) died massively all over the world since 2008 in relation with OsHV-1 infection. During mortality episodes, sick and dead oysters are not separated from healthy live ones, and left to decay in the surrounding environment, with unknown consequences for the nutrient cycle and planktonic microbial components (PMC). The present study aimed to elucidate for the first time the interactions between oyster juveniles and PMC during a mortality episode. Innovative... |
| Tipo: Text |
Palavras-chave: Magallana gigas; Crassostrea gigas; Spat; OsHV-1 mu Var; Mortality; Picoplankton; Heterotrophic flagellates; Ciliates; Uronema; Balanion. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00474/58559/61115.pdf |
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| Lagarde, Franck; Fiandrino, Annie; Richard, Marion; Bernard, Ismael; Mortreux, Serge; Ubertini, Martin; Chiantella, Claude; Boj, Marie; Meddah, Slem; Leurion, Axel; Soriano, Solenn; Fuhrmann, Marine; Le Gall, Patrik; Chiera, Caroline; Berteaux, Tom; Guillou, Jean-louis; Roque D'Orbcastel, Emmanuelle; Perignon, Adeline; Bonnet, Delphine; Roques, Cecile; Bec, Beatrice; Cochet, Helene; Gervasoni, Erika; Miron, Gilles; Pouvreau, Stephane. |
| Since spat mortality events that were firstly detected in 2008, Mediterranean shellfish industry seeks to exploit the Pacific oyster spat from lagoon natural recruitment. The CRCM, Cepralmar and Ifremer developed accordingly a research project named PRONAMED Phase 1 and 2 - 2010-2014, in order to define the economic potential of spatfall and improve knowledge of the reproductive cycle of Crassostrea gigas in this specific environmental context. The results of the past three year‘s study (2012, 2013, 2014) showed that broodstock have the ability to provide larvae after sexual maturation and spawning. A coincidence was noted between moon phase (new and full moon) and spawnings with an amplifying effect of storms on the intensity of spawning (Ubertini et al.... |
| Tipo: Text |
Palavras-chave: Lagune; Recrutement; Naissain; Huître creuse; Ecologie larvaire; Cycle de reproduction; Captage naturel.; Lagoon; Recruitment; Spat; Pacific oysters; Larval ecology; Reproduction Cycle; Natural spat collection.. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00279/39054/37620.pdf |
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| Bec, Beatrice; Collos, Yves; Souchu, Philippe; Vaquer, Andre; Lautier, Jacques; Fiandrino, Annie; Benau, Laurent; Orsoni, Valerie; Laugier, Thierry. |
| We explored the role of natural and anthropogenic environmental perturbations in shaping the community structure and dynamics of pico- and nanophytoplankton in coastal waters. The distribution patterns of phycoerythrin-rich picocyanobacteria (PE-CYAN) and phycocyanin-rich picocyanobacteria (PC-CYAN), autotrophic picoeukaryotes (PEUK) and nanophytoplankton (NANO) were examined over a period of 3 yr in 24 Mediterranean coastal lagoons displaying wide trophic gradients (from 0.2 to 630 mu g chlorophyll a [chl a] l(-1)) and salinity gradients (from fresh to marine waters). In summer, picoplanktonic abundances reached 3 x 10(8) cells l(-1), 5 x 10(9) cells l(-1) and 6 x 10(10) cells l(-1) for PE-CYAN, PC-CYAN and PEUK, respectively. PE-CYAN and PC-CYAN showed... |
| Tipo: Text |
Palavras-chave: Autotrophic picoeukaryotes; Picocyanobacteria; Nanophytoplankton; Abundance; Biomass; Eutrophication; Mediterranean lagoons. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00031/14267/11547.pdf |
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| Lagarde, Franck; Fiandrino, Annie; Ubertini, Martin; Roque D'Orbcastel, Emmanuelle; Mortreux, Serge; Chiantella, Claude; Bec, Beatrice; Bonnet, Delphine; Roques, Cécile; Bernard, Ismael; Richard, Marion; Guyondet, Thomas; Pouvreau, Stephane; Lett, Christophe. |
| The recent discovery of Pacific oyster Crassostrea gigas (also known as Magallana gigas) spatfields in a Mediterranean lagoon intensely exploited for shellfish farming (Thau lagoon) revealed significant contrasts in spatial patterns of recruitment. We evaluated the processes that drive spatial patterns in oyster recruitment by comparing observed recruitment, simulated hydrodynamic connectivity and ecological variables. We hypothesized that spatial variability of recruitment depends on (1) hydrodynamic connectivity and (2) the ecology of the larval supply, settlement, metamorphosis, survival and biotic environmental parameters. We assessed recruitment at 6-8 experimental sites by larval sampling and spat collection inside and outside oyster farming areas... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Coastal lagoon; Larval ecology; Spatial patterns; Connectivity; Settlement; Recruitment; Oligotrophication. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00598/70981/69271.pdf |
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| Maurer, Daniele; Bec, Beatrice; Neaud-masson, Nadine; Rumebe, Myriam; Auby, Isabelle; Gremare, Antoine. |
| Since the introduction of the oyster Crassostrea gigas in the Arcachon Basin, the sale of oysters has been banned for the first time in 2005, based on mouse bioassay positive for lipophilic toxins. If the beginning of this episode could be related to the presence in water of microalgae of the genus Dinophysis and okadaic acid in the hepatopancreas of oyster, it has not been the same for the end of the period, which was qualified as of "atypical toxicity episode" or "toxicity of unknown origin", that is to say, "an episode of shellfish contamination, revealed in a toxic response in mice by intraperitoneal injection , whose origin can not be explained by the presence of known toxins usually sought”. Between 1993 and 2009, 7 episodes Dinophysis or okadaic... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00031/14245/11526.pdf |
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| Derolez, Valerie; Malet, Nathalie; Fiandrino, Annie; Lagarde, Franck; Richard, Marion; Ouisse, Vincent; Bec, Beatrice; Aliaume, Catherine. |
| Thau lagoon is a large Mediterranean coastal lagoons and it supports traditional shellfish farming activities. It has been subject to eutrophication leading to major anoxic events associated with massive mortalities of shellfish stocks. Since the 1970s, improvements have been made to wastewater treatment systems, which have gradually led to oligotrophication of the lagoon. The aim of our study was to determine how the decrease in nutrient inputs resulted in major ecological changes in Thau lagoon, by analysing five decades of time-series (1970–2018) of observations on pelagic and benthic autotrophic communities. We were able to identify two periods during the oligotrophication process. Period 1 (1970–1992) was considered a eutrophic period, characterised... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00629/74068/73521.pdf |
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| Lagarde, Franck; Roque D'Orbcastel, Emmanuelle; Perignon, Adeline; Mortreux, Serge; Fuhrmann, Marine; Le Gall, Patrik; Leurion, Axel; Chiantella, Claude; Bec, Beatrice; Roques, Cecile; Bonnet, Delphine; Cochet, Helene; Boj, Marie; Gervasoni, Erika; Miron, Gilles; Fiandrino, Annie; Pouvreau, Stephane; Pernet, Fabrice. |
| We bring new items in connection with the origins of the natural recruitment variability of the Pacific oyster Crassostrea gigas in Thau lagoon. A poor relationship between " number of larvae" and "number of spat" in 2012 shows a biological lock around oysterculture areas during the metamorphosis in spite of better success of recruitment outside shellfish farming zone. A comprehensive analysis of environmental factors effects and the development of prognosis tools are planned to assist oysterfarmers in rationalization of natural oyster recruitment around Mediterranean lagoon. |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00165/27653/25822.pdf |
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| Collos, Yves; Bec, Beatrice; Jauzein, Cecile; Abadie, Eric; Laugier, Thierry; Lautier, Jacques; Pastoureaud, Annie; Souchu, Philippe; Vaquer, Andre. |
| Time series data have been examined in Thau lagoon (Southern France) from 1972 to 2006 for water temperature, salinity, nutrients and from 1987 to 2006 for phytoplankton. A first main trend identified is an increase in mean annual water temperature (1.5 degrees C over 33 years or 0.045 degrees C/year) that was not evenly distributed among seasons. The highest rate of increase was in the spring (+ 3.0 degrees C over 33 years), followed by summer (+ 2.0 degrees C and fall (+ 1.7 degrees C. In winter, no significant increase over the 33 year period could be found. A second clear trend is a large decrease in soluble reactive phosphorus (SRP) concentration over the same 33 year period (summer values decreased from 10 mu M to 1 mu M. while winter values... |
| Tipo: Text |
Palavras-chave: Skeletonema costatum; Alexandrium catenella; Picocyanobacteria; Oligotrophication; Long term variability; Thau lagoon. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6420.pdf |
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| Souchu, Philippe; Bec, Beatrice; Smith, Val H.; Laugier, Thierry; Fiandrino, Annie; Benau, Laurent; Orsoni, Valerie; Collos, Yves; Vaquer, Andre. |
| A cross-ecosystem comparison of data obtained from 20 French Mediterranean lagoons with contrasting eutrophication status provided the basis for investigating the variables that best predict chlorophyll a (Chl a) concentrations and nutrient limitation of phytoplankton biomass along a strong nutrient enrichment gradient. Summer concentrations of dissolved inorganic nitrogen (DIN) and phosphorus (DIP) comprised only a small fraction of total nitrogen (TN) and total phosphorus (TP). On the basis of inorganic nutrient concentrations, the most oligotrophic lagoons appeared to be phosphorus-limited, with a tendency towards the development of nitrogen limitation as eutrophication increased, as evidenced by decreasing DIN:DIP ratios. A weak but significantly... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00003/11444/8002.pdf |
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| Leruste, A.; Pasqualini, V.; Garrido, M.; Malet, Nathalie; De Wit, R.; Bec, Beatrice. |
| Short-term bioassays were conducted in Biguglia lagoon (Corsica) to study the physiological and behavioral responses of phytoplankton to N- and P-availability. Natural communities were collected in two stations representative of the two sub-basins, at three periods with contrasting environmental characteristics to address the impact of seasonal variability. These samples were separately enriched with a full N and P enrichment, and with enrichments minus N or minus P. Phytoplankton size structuration, diversity, and growth of the total phytoplankton, the micro-, nano- and ultraphytoplankton were evaluated using spectrofluorimetry, and optical microscopy. Results showed that the communities were fueled by NO3− in the wet periods (autumn and spring) and NH4+... |
| Tipo: Text |
Palavras-chave: Growth rate; Dilution experiment; Eutrophication; Functional traits. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00481/59238/61948.pdf |
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| Leruste, A; Guilhaumon, F; De Wit, R; Malet, Nathalie; Collos, Y; Bec, Beatrice. |
| We studied a mesotrophic and a hypertrophic Mediterranean coastal lagoon, both of which had been simultaneously subjected to a nutrient input reduction for 9 yr. We compared these 2 lagoons to an oligotrophic coastal lagoon. Using bioassays comprising 24 h incubations with added phosphorus and/or ammonium, we investigated the response of the phytoplankton communities to nutrient enrichment during summer in terms of biomass, size class structure, abundance and growth. For nitrogen and phosphorus, we identified which nutrient limited phytoplankton growth, and what strategies of nutrient exploitation the communities adopted to cope with these limitations. Ultraphytoplankton dominated the 3 communities, but it differed in composition among the lagoons. Green... |
| Tipo: Text |
Palavras-chave: Growth rate; Nutrient limitation; Dilution experiment; HPLC. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00508/61978/66084.pdf |
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| Derolez, Valerie; Bec, Beatrice; Munaron, Dominique; Fiandrino, Annie; Pete, Romain; Simier, Monique; Souchu, Philippe; Laugier, Thierry; Aliaume, Catherine; Malet, Nathalie. |
| Tipo: Text |
Palavras-chave: Recovery; Oligotrophication; Coastal lagoons; Urban inputs; Nutrients. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00478/58953/61574.pdf |
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| Lagarde, Franck; Roque D'Orbcastel, Emmanuelle; Ubertini, Martin; Mortreux, Serge; Bernard, Ismael; Fiandrino, Annie; Chiantella, Claude; Bec, Beatrice; Roques, Cecile; Bonnet, Delphine; Miron, Gilles; Richard, Marion; Pouvreau, Stephane; Lett, Christophe. |
| In the context of increasing demand for environmental recovery, aquatic systems may face the challenge of evolving under oligotrophication. This is the case in Mediterranean lagoons, in particular the shellfish-farmed Thau lagoon in France, where we studied recruitment of the Pacific oyster Crassostrea gigas. Oyster spat and environmental parameters were monitored at several sampling sites for 3 yr (2012 to 2014) using an original method with a temporal overlap deployment of collectors to study pre- and post-settlement processes and to identify the best conditions for recruitment. Contrary to the ‘no Pacific oyster reproduction’ paradigm in Mediterranean lagoons, our study showed that recruitment of this introduced species is possible in the Thau lagoon at... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Oyster spat; Pediveliger; Metamorphosis; Recruitment; Oligo trophication; Larval ecology. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00398/50899/51672.pdf |
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| Lagarde, Franck; Richard, Marion; Bec, Beatrice; Roques, Cecile; Mortreux, Serge; Bernard, Ismael; Chiantella, Claude; Messiaen, Gregory; Nadalini, Jean-bruno; Hori, Masakazu; Hamaguchi, Masami; Pouvreau, Stephane; Roque D'Orbcastel, Emmanuelle; Tremblay, Rejean. |
| Reproduction and recruitment of benthic invertebrates are influenced by the climate and by the ecological structure of marine ecosystems, along with local anthropogenic pressures such as eutrophication or oligotrophication. Using the Pacific oyster Crassostrea gigas as a biological model, we tested the hypothesis that the variability in prodissoconch II (PII) size (i.e. size at metamorphosis) depends on ecological functioning. Settlement and recruitment were assessed at 5 sampling sites on the French Mediterranean shellfish farmed Thau lagoon during the main summer recruitment events in 3 consecutive years (2012-2014). Hydrobiological and planktonic analyses were conducted at 3 sampling sites. Our results showed that recruitment was extremely... |
| Tipo: Text |
Palavras-chave: Larval ecology; Recruitment; Prodissoconch II; Crassostrea gigas; Oligotrophication; Cryptophytes; Thau lagoon. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00454/56613/58334.pdf |
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| Derolez, Valerie; Soudant, Dominique; Malet, Nathalie; Chiantella, Claude; Richard, Marion; Abadie, Eric; Aliaume, Catherine; Bec, Beatrice. |
| Mediterranean costal lagoons have been exposed to anthropic eutrophication for decades. Thau lagoon is one of the largest among them and provides many ecosystem services including shellfish farming. Considerable efforts were made between the 1970s and the late 2000s to improve the wastewater treatment systems in the lagoon watershed. A decrease in nutrient inputs to Thau lagoon was subsequently observed, evidence for the start of a recovery process in Thau lagoon, following oligotrophication. This decrease has significant consequences for ecosystem communities, above all primary producers. In our study, we characterised and quantified long-term changes by analysing long monitoring time-series (1998-2016) of phytoplankton biomass, abundance and composition... |
| Tipo: Text |
Palavras-chave: Eutrophication; Oligotrophication; Nutrients; Recovery; Phytoplankton community shift; Mediterranean coastal lagoon. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00629/74063/73514.pdf |
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| Registros recuperados: 19 | |
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