Thierry Laugier

Informations

EMAIL : thierry.laugier ifremer.fr

SITE PERSO : TOUTES MES PUBLICATIONS

Institut : IFREMER

GRADE : Chercheur

Thèmes de recherche : Aquacultures durables

Systèmes littoraux d’usages multiples

Publications

2019
Derolez, V., et al. "Recovery trajectories following the reduction of urban nutrient inputs along the eutrophication gradient in French Mediterranean lagoons." Ocean & Coastal Management. 171 (2019): 1–10. 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). Mots-Clés: Coastal lagoons; Nutrients; Oligotrophication; Recovery; Urban inputs Lien permanent \| Sauvegarder la référence: RTF PDF LaTeX \| Exporter enregistrement: BibTeX Endnote ISI RIS Atom XML MODS XML ODF XML Word XML
2017
Pasqualini, V., et al. "Spatiotemporal dynamics of submerged macrophyte status and watershed exploitation in a Mediterranean coastal lagoon: Understanding critical factors in ecosystem degradation and restoration." Ecological Engineering. 102 (2017): 1–14. Résumé: Increases in the intensity of disturbances in coastal lagoons can lead to shifts in vegetation from aquatic angiosperms to macroalgal or phytoplankton communities. Such abrupt and discontinuous responses are facilitated by instability in the equilibrium controlling the trajectory of the community response. We hypothesized that the shift in macrophyte populations is reversible, and that this reversibility is dependent on changes in the pressures exerted on the watershed and lagoon functioning. Biguglia lagoon (Mediterranean Sea, Corsica) is an interesting case study for the evaluation of long-term coastal lagoon ecosystem functioning and the trajectory of submerged macrophyte responses to disturbances, to facilitate the appropriate restoration of ecosystems. We used historical data for a two hundred-year period to assess changes in human activities on the watershed of the Biguglia lagoon. Macrophyte mapping (from 1970) and monitoring data for dynamics (from 1999) were used to investigate the trajectory of the community response. The changes observed in this watershed included a large number of hydrological developments affecting salinity and resulting in changes in macrophyte distribution. Nutrient inputs over the last 40 years have led to a shift in the aquatic vegetation from predominantly aquatic angiosperm community to macroalgae and phytoplankton in 2007 (dystrophic crisis). Changes in hydrological management and improvements in sewage treatment after 2007 led to a significant increase of aquatic angiosperms over a relatively short period of time (4–5 years), particularly for Ruppia cirrhosa and Stuckenia pectinata. There has been a significant resurgence of Najas marina, due to changes in salinity. The observed community shift suggests that Biguglia lagoon is resilient and that the transition may be reversible. The restored communities closely resemble those present before disturbance. These findings demonstrate the need to understand watershed exploitation and ecosystem variability in lagoon restoration. Mots-Clés: Coastal lagoons; Community shifts; Human pressures; Long-term changes; Submerged macrophytes Lien permanent \| Sauvegarder la référence: RTF PDF LaTeX \| Exporter enregistrement: BibTeX Endnote ISI RIS Atom XML MODS XML ODF XML Word XML
2013
Brehmer, P., et al. "Does coastal lagoon habitat quality affect fish growth rate and their recruitment? Insights from fishing and acoustic surveys." Estuar. Coast. Shelf Sci.. 126 (2013): 1–6. Résumé: Ensuring the sustainability of fish resources necessitates understanding their interaction with coastal habitats, which is becoming ever more challenging in the context of ever increasing anthropogenic pressures. The ability of coastal lagoons, exposed to major sources of disturbance, to provide resources and suitable habitats for growth and survival of juvenile fish is especially important. We analysed three lagoons with different ecological statuses and habitat quality on the basis of their eutrophication and ecotoxicity (Trix test) levels. Fish abundances were sampled using fishing and horizontal beaming acoustic surveys with the same protocols in the same year. The relative abundance of Anguilla anguilla, Dicentrarchus labrax or the Mugilidae group was not an indicator of habitat quality, whereas Atherina boyeri and Sparus aurata appeared to be more sensitive to habitat quality. Fish abundance was higher in the two lagoons with high eutrophication and ecotoxicity levels than in the less impacted lagoon, while fish sizes were significantly higher in the two most severely impacted lagoons. This leads us to suggest low habitat quality may increase fish growth rate (by the mean of a cascading effect), but may reduce lagoon juvenile abundance by increasing larval mortality. Such a hypothesis needs to be further validated using greater investigations which take into account more influences on fish growth and recruitment in such variable environments under complex multi-stressor conditions. (C) 2013 Elsevier Ltd. All rights reserved. Mots-Clés: Ecotoxicity; amphidromous; diversity; estuarine; exploitation; fish; habitat quality; indicators; lagoon; management; multibeam sonar; shallow water; size; target strength; thau lagoon; winter flounder Lien permanent \| Sauvegarder la référence: RTF PDF LaTeX \| Exporter enregistrement: BibTeX Endnote ISI RIS Atom XML MODS XML ODF XML Word XML
Genovesi, B., et al. "Influences of sedimentation and hydrodynamics on the spatial distribution of Alexandrium catenella/tamarense resting cysts in a shellfish farming lagoon impacted by toxic blooms." Harmful Algae. 25 (2013): 15–25. Mots-Clés: Alexandrium; Hydrodynamics; Mapping; Resting cyst; Sediment; Spatial correlation; Thau Lagoon (Mediterranean Sea) Lien permanent \| Sauvegarder la référence: RTF PDF LaTeX \| Exporter enregistrement: BibTeX Endnote ISI RIS Atom XML MODS XML ODF XML Word XML
2011
Bec, B., et al. "Distribution of picophytoplankton and nanophytoplankton along an anthropogenic eutrophication gradient in French Mediterranean coastal lagoons." Aquatic Microbial Ecology. 63.1 (2011): 29–45. Lien permanent \| Sauvegarder la référence: RTF PDF LaTeX \| Exporter enregistrement: BibTeX Endnote ISI RIS Atom XML MODS XML ODF XML Word XML
Brehmer, P., et al. "Field investigations and multi-indicators for shallow water lagoon management: perspective for societal benefit." Aquatic Conservation-Marine and Freshwater Ecosystems. 21.7 (2011): 728–742. Lien permanent \| Sauvegarder la référence: RTF PDF LaTeX \| Exporter enregistrement: BibTeX Endnote ISI RIS Atom XML MODS XML ODF XML Word XML
Castro-Jiménez, J., et al. "Atmospheric concentrations, occurrence and deposition of persistent organic pollutants (POPs) in a Mediterranean coastal site (Etang de Thau, France)." Environmental Pollution. 159.7 (2011): 1948–1956. Lien permanent \| Sauvegarder la référence: RTF PDF LaTeX \| Exporter enregistrement: BibTeX Endnote ISI RIS Atom XML MODS XML ODF XML Word XML
2010
Souchu, P., et al. "Patterns in nutrient limitation and chlorophyll a along an anthropogenic eutrophication gradient in French Mediterranean coastal lagoons." Canadian Journal of Fisheries and Aquatic Sciences. 67.4 (2010): 743–753. Lien permanent \| Sauvegarder la référence: RTF PDF LaTeX \| Exporter enregistrement: BibTeX Endnote ISI RIS Atom XML MODS XML ODF XML Word XML
2009
Collos, Y., et al. "Oligotrophication and emergence of picocyanobacteria and a toxic dinoflagellate in Thau lagoon, southern France." Journal of Sea Research. 61.1-2 (2009): 68–75. Lien permanent \| Sauvegarder la référence: RTF PDF LaTeX \| Exporter enregistrement: BibTeX Endnote ISI RIS Atom XML MODS XML ODF XML Word XML

Membres de Aquacultures durables

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Membres de Systèmes littoraux d’usages multiples

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MARBEC MARine Biodiversity, Exploitation and Conservation, est une unité de recherche qui regroupe des personnels de 4 organismes : l’IRD, l’Ifremer, l’UM et le CNRS. Son objectif est l’étude de la biodiversité marine des écosystèmes lagunaires, côtiers et hauturiers à différents niveaux d’intégration, depuis les aspects moléculaires, individuels, populationnels et communautaires, et des usages de cette biodiversité par l’Homme. Nous rejoindre