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Auteur De Wit, R.; Rey-Valette, H.; Balavoine, J.; Ouisse, V.; Lifran, R.
Titre Restoration ecology of coastal lagoons: new methods for the prediction of ecological trajectories and economic valuation Type Article scientifique
Année 2017 Publication Revue Abrégée Aquatic Conserv: Mar. Freshw. Ecosyst.
Volume 27 Numéro 1 Pages 137-157
Mots-Clés coastal lagoon; ecosystem services; ecosystem trajectory' nutrient enrichment; marine and brackish Magnoliophyta; oligotrophication; Phytoplankton; seagrass meadow; sediment N and P contents; Water Framework Directive; willingness to pay (WTP)
Résumé * 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; and (iii) to predict ecosystem trajectories for the different cases. Extension of Magnoliophyta meadows can be taken as a proxy for ecosystem restoration as they favour the increase of several fish (seahorse) and bird (ducks, swans, herons) species, albeit they represent a trade-off for greater flamingos. Additional measures for active ecosystem restoration were only recommended for the most impaired lagoon Méjean, while the least impaired lagoon Ingril is already on a trajectory of spontaneous recovery. * A multiple contingent valuation considering four different management options for the Méjean lagoon was used in a pilot study based on face-to-face interviews with 159 respondents. Three levels of ecosystem restoration were expressed in terms of recovery of Magnoliophyta meadows, including their impact on emblematic fish and avifauna. These were combined with different options for access (status quo, increasing access, increasing access with measures to reduce disturbance). The results show a willingness of local populations to pay per year about €25 for the highest level of ecological restoration, while they were only willing to allocate about €5 for additional footpaths and hides.

Copyright © 2015 John Wiley & Sons, Ltd.
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ISSN 1099-0755 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2100
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Auteur Derolez, V.; Bec, B.; Munaron, D.; Fiandrino, A.; Pete, R.; Simier, M.; Souchu, P.; Laugier, T.; Aliaume, C.; Malet, N.
Titre Recovery trajectories following the reduction of urban nutrient inputs along the eutrophication gradient in French Mediterranean lagoons Type Article scientifique
Année 2019 Publication Revue Abrégée Ocean & Coastal Management
Volume 171 Numéro Pages 1-10
Mots-Clés Coastal lagoons; Nutrients; Oligotrophication; Recovery; Urban inputs
Résumé French Mediterranean coastal lagoons have been subject to huge inputs of urban nutrients for decades leading to the eutrophication of these vulnerable ecosystems. In response to new environmental regulations, some of the lagoons have recently been the subject of large-scale management actions targeting the waste water treatment systems located on their watersheds. While the eutrophication of coastal ecosystems is well described, recovery trajectories have only recently been studied. To assess the rapidity and the extent of the effect of the remediation actions, we analysed data from a 14-year time series resulting from the monitoring of nutrients, biomass and the abundance of phytoplankton in the water column of French Mediterranean coastal lagoons covering the whole anthropogenic eutrophication gradient. Following a 50% to 80% reduction in total phosphorus (TP) and total nitrogen (TN) urban loadings from the watershed of hypertrophic and eutrophic ecosystems, the integrative parameters chlorophyll a, TN and TP, provide evidence for a rapid response (1 to 3 years) and for an almost complete recovery, suggesting no hysteresis for the eutrophic lagoon. However, our findings also show that recovery patterns depend on the eutrophication status before remediation and may include feedback responses. The different responses revealed by our results should help stakeholders prioritise remediation actions and identify appropriate restoration goals, especially in light of the targets of the Water Framework Directive (WFD).
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Volume de collection Numéro de collection Edition
ISSN 0964-5691 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2493
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Auteur Derolez, V.; Soudant, D.; Malet, N.; Chiantella, C.; Richard, M.; Abadie, E.; Aliaume, C.; Bec, B.
Titre Two decades of oligotrophication: Evidence for a phytoplankton community shift in the coastal lagoon of Thau (Mediterranean Sea, France) Type Article scientifique
Année 2020 Publication Revue Abrégée Estuarine, Coastal and Shelf Science
Volume Numéro Pages 106810
Mots-Clés Eutrophication; Mediterranean coastal lagoon; Nutrients; Oligotrophication; Phytoplankton community shift; Recovery
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ISSN 0272-7714 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2776
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Auteur Lagarde, F.; Fiandrino, A.; Ubertini, M.; d'Orbcastel, E.R.; Mortreux, S.; Chiantella, C.; Bec, B.; Bonnet, D.; Roques, C.; Bernard, I.; Richard, M.; Guyondet, T.; Pouvreau, S.; Lett, C.
Titre Duality of trophic supply and hydrodynamic connectivity drives spatial patterns of Pacific oyster recruitment Type Article scientifique
Année 2019 Publication Revue Abrégée Marine Ecology Progress Series
Volume 632 Numéro Pages 81-100
Mots-Clés Coastal lagoon; Connectivity; Crassostrea gigas; Larval ecology; Oligotrophication; Recruitment; Settlement; Spatial patterns
Résumé 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 and on an east-west gradient, from 2012-2014. Hydrodynamic connectivity was simulated using a numerical 3D transport model assessed with a Eulerian indicator. The supply of large umbo larvae did not differ significantly inside and outside oyster farming areas, whereas the supply of pediveligers to sites outside shellfish farms was structured by hydrodynamic connectivity. Inside shellfish farming zones, unfavorable conditions due to trophic competition with filter-feeders jeopardized their settlement. In this case, our results suggest loss of settlement competence by oyster larvae. This confirms our hypothesis of top-down trophic control by the oysters inside farming zones of Thau lagoon in summer that fails to meet the ecological requirements of these areas as oyster nurseries. Knowledge of oyster dispersal, connectivity and recruitment in coastal lagoons will help local development of sustainable natural spat collection. On a global scale, our method could be transposed to other basins or used for other species such as mussels, clams or scallops, to better understand the spatial patterns of bivalve recruitment. Management of the oyster industry based on natural spat collection will help develop a sustainable activity, based on locally adapted oyster strains but also by reducing the risks of transferring pathogens between basins and the global carbon footprint of this industry.
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Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0171-8630, 1616-1599 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2673
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Auteur Lagarde, F.; Richard, M.; Bec, B.; Roques, C.; Mortreux, S.; Bernard, I.; Chiantella, C.; Messiaen, G.; Nadalini, J.-B.; Hori, M.; Hamaguchi, M.; Pouvreau, S.; ROQUE D'ORBCASTEL, E.; Tremblay, R.
Titre Trophic environments influence size at metamorphosis and recruitment performance of Pacific oysters Type Article scientifique
Année 2018 Publication Revue Abrégée Marine Ecology Progress Series
Volume 602 Numéro Pages 135-153
Mots-Clés Crassostrea gigas; Cryptophytes; Larval ecology; Oligotrophication; Prodissoconch II; Recruitment; Thau lagoon
Résumé 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 heterogeneous, ranging from 0 to 260 ± 27 SE ind. dm-2 throughout the ecosystem and was linked with variability in PII size, which ranged from 180 to 296 µm. The annual temporal pattern of PII sizes appeared to be controlled by temperature during the settlement period, whereas the spatial pattern depended on phytoplankton biomass and on the trophic functioning of the ecosystem. Smaller PII sizes were significantly correlated with the highest phytoplankton biomass, while larger PII sizes were positively correlated with mixotrophic cryptophyte abundance. We found an inverse relationship between PII size and survival after metamorphosis, showing that recruitment success was associated with smaller PII sizes. Regional climate conditions and local trophic functioning appear to be key factors in metamorphosis and consequently contribute to recruitment heterogeneity. Further studies should be performed in other ecosystems following an oligotrophication trajectory to generalize this result.
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Editeur Lieu de Publication Éditeur
Langue en Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0171-8630, 1616-1599 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2398
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