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Auteur Ramirez-Romero, E.; Molinero, J.C.; Paulsen, M.; Javidpour, J.; Clemmesen, C.; Sommer, U.
Titre Quantifying top-down control and ecological traits of the scyphozoan Aurelia aurita through a dynamic plankton model Type Article scientifique
Année (down) 2018 Publication Revue Abrégée J. Plankton Res.
Volume 40 Numéro 6 Pages 678-692
Mots-Clés 2 hydromedusae; annual cycle; baltic sea; coastal ecosystem; common jellyfish; ctenophore mnemiopsis-leidyi; jellyfish; kiel-bight; planktonic food web; population modeling; population-dynamics; predation impact; sarsia-tubulosa; stage-resolved model; zooplankton
Résumé Aurelia aurita (Linneaus, 1758) is a cosmopolitan scyphozoan, probably the most investigated jellyfish in temperate and highly productive coastal ecosystems. Despite a prominent top-down control in plankton food webs, a mechanistic understanding of A. aurita population dynamics and trophic interactions has been barely addressed. Here we develop a food web dynamic model to assess A. aurita role in the seasonal plankton dynamics of the Kiel Fjord, southwestern Baltic Sea. The model couples low trophic level dynamics, based on a classical Nutrient Phytoplankton Zooplankton Detritus (NPZD) model, to a stage-resolved copepod model (referencing Pseudocalanus sp.) and a jellyfish model (A. aurita ephyra and medusa) as consumers and predators, respectively. Simulations showed the relevance of high abundances of A. aurita, which appear related with warm winter temperatures, promoting a shift from a copepod-dominated food web to a ciliate and medusa dominated one. The model captured the intraspecific competition triggered by the medusae abundance and characterized by a negative relationship between population density and individual size/weight. Our results provide a mechanistic understanding of an emergent trait such as size shaping the food web functioning, driving predation rates and population dynamics of A. aurita, driving its sexual reproductive strategy at the end of the pelagic phase.
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Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0142-7873 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2476
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Auteur Hoang, H.T.T.; Duong, T.T.; Nguyen, K.T.; Le, Q.T.P.; Luu, M.T.N.; Trinh, D.A.; Le, A.H.; Ho, C.T.; Dang, K.D.; Némery, J.; Orange, D.; Klein, J.
Titre Impact of anthropogenic activities on water quality and plankton communities in the Day River (Red River Delta, Vietnam) Type Article scientifique
Année (down) 2018 Publication Revue Abrégée Environ Monit Assess
Volume 190 Numéro 2 Pages 67
Mots-Clés Water quality; Tropical; Vietnam; Day River; Plankton communities; Red River Delta
Résumé Planktons are a major component of food web structure in aquatic ecosystems. Their distribution and community structure are driven by the combination and interactions between physical, chemical, and biological factors within the environment. In the present study, water quality and the community structure of phytoplankton and zooplankton were monthly investigated from January to December 2015 at 11 sampling sites along the gradient course of the Day River (Red River Delta, northern Vietnam). The study demonstrated that the Day River was eutrophic with the average values of total phosphorus concentration 0.17 mg/L, total nitrogen concentration 1.98 mg/L, and Chl a 54 μg/L. Microscopic plankton analysis showed that phytoplankton comprised 87 species belonging to seven groups in which Chlorophyceae, Bacillariophyceae, and Cyanobacteria accounted for the most important constituents of the river's phytoplankton assemblage. A total 53 zooplankton species belonging to three main groups including Copepoda, Cladocera, and Rotatoria were identified. Plankton biomass values were greatest in rainy season (3002.10-3 cell/L for phytoplankton and 12.573 individuals/m3 for zooplankton). Using principal correspondence and Pearson correlation analyses, it was found that the Day River was divided into three main site groups based on water quality and characteristics of plankton community. Temperature and nutrients (total phosphorus and total nitrogen) are key factors regulating plankton abundance and distribution in the Day River.
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Langue eng Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1573-2959 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2263
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Auteur Meddeb, M.; Grami, B.; Chaalali, A.; Haraldsson, M.; Niquil, N.; Pringault, O.; Sakka Hlaili, A.
Titre Plankton food-web functioning in anthropogenically impacted coastal waters (SW Mediterranean Sea): an ecological network analysis Type Article scientifique
Année (down) 2018 Publication Revue Abrégée Progress in Oceanography
Volume Numéro Pages
Mots-Clés Ecological Network Analysis; Food-web modelling; Mediterranean coastal waters; plankton ecology
Résumé The study is the first attempt to (i) model spring food webs in three SW Mediterranean ecosystems which are under different anthropogenic pressures and (ii) to project the consequence of this stress on their function. Linear inverse models were built using the Monte Carlo method coupled with Markov Chains to characterize the food-web status of the Lagoon, the Channel (inshore waters under high eutrophication and chemical contamination) and the Bay of Bizerte (offshore waters under less anthropogenic pressure). Ecological network analysis was used for the description of structural and functional properties of each food web and for inter-ecosystem comparisons. Our results showed that more carbon was produced by phytoplankton in the inshore waters (966–1234 mg C m-2 d-1) compared to the Bay (727 mg C m-2 d-1). The total ecosystem carbon inputs into the three food webs was supported by high primary production, which was mainly due to >10µm algae. However, the three carbon pathways were characterized by low detritivory and a high herbivory which was mainly assigned to protozooplankton. This latter was efficient in channelling biogenic carbon. In the Lagoon and the Channel, foods webs acted almost as a multivorous structure with a tendency towards herbivorous one, whereas in the Bay the herbivorous pathway was more dominant. Ecological indices revealed that the Lagoon and the Channel food webs/systems had high total system throughput and thus were more active than the Bay. The Bay food web, which had a high relative ascendency value, was more organized and specialized. This inter–ecosystem difference could be due to the varying levels of anthropogenic impact among sites. Indeed, the low value of Finn’s cycling index indicated that the three systems are disturbed, but the Lagoon and the Channel, with low average path lengths, appeared to be more stressed, as both sites have undergone higher chemical pollution and nutrient loading. This study shows that ecosystem models combined with ecological indices provide a powerful approach to detect change in environmental status and anthropogenic impacts.
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Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0079-6611 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2292
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Auteur Blanchet, M.; Pringault, O.; Panagiotopoulos, C.; Lefevre, D.; Charriere, B.; Ghiglione, J.-F.; Fernandez, C.; Aparicio, F.L.; Marrase, C.; Catala, P.; Oriol, L.; Caparros, J.; Joux, F.
Titre When riverine dissolved organic matter (DOM) meets labile DOM in coastal waters: changes in bacterial community activity and composition Type Article scientifique
Année (down) 2017 Publication Revue Abrégée Aquat. Sci.
Volume 79 Numéro 1 Pages 27-43
Mots-Clés Bacterial community composition; bacterioplankton; biodegradation; carbon; coastal waters; Dissolved organic matter; Fluorescence; growth efficiency; lake water; marine; Mediterranean Sea; open-ocean; Priming effect; rhone river; terrestrial
Résumé Heterotrophic bacterial communities in marine environments are exposed to a heterogeneous mixture of dissolved organic compounds with different bioreactivity that may control both their activity and composition. The coastal environment is an example of a mixing area where recalcitrant allochthonous organic matter from rivers can encounter labile organic matter from marine phytoplanktonic blooms. The objective of this study was to explore the effects of mixed qualities of dissolved organic matter (DOM) on bacterial community activity (BCA) and bacterial community composition (BCC) and to test for a priming effect when DOM sources are added in combination. Coastal marine bacterial communities were incubated separately with a mixture of amino acids and with natural riverine DOM or with both sources together for 42 days. Addition of amino acids alone or in combination with riverine DOM led to a similar stimulation of BCA compared to control condition, whereas addition of riverine DOM alone did not modify BCA compared to the control. On the contrary, BCC analyzed by 16S rRNA gene pyrosequencing was not affected by the addition of amino acids alone, but changed dramatically with riverine DOM alone or in combination with amino acids. Our results show that changes in BCA and BCC can be driven by different types of DOM, but that these changes are not necessarily coupled. Moreover, the addition of labile DOM did not modify the microbial decomposition of riverine DOM, nor the BCC, suggesting that a priming effect did not occur under these experimental conditions.
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Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1015-1621 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2090
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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 (down) 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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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 1099-0755 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2100
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