Search

Your search keyword '"Antoine Gilbert"' showing total 17 results
Start Over Author "Antoine Gilbert" Language english
17 results on '"Antoine Gilbert"'

1. Radiosensitizing Effect of PARP Inhibition on Chondrosarcoma and Chondrocyte Cells Is Dependent on Radiation LET

Author

Antoine Gilbert, Mihaela Tudor, Amandine Delaunay, Raphaël Leman, Julien Levilly, Alexandre Atkinson, Laurent Castéra, Anca Dinischiotu, Diana Iulia Savu, Samuel Valable, and François Chevalier

Subjects
carbon ion irradiation, chondrosarcoma, PARP inhibitor, DNA damages, Microbiology, QR1-502
Abstract

Chondrosarcoma is a rare malignant tumor that forms in bone and cartilage. The primary treatment involves surgical removal of the tumor with a margin of healthy tissue. Especially if complete surgical removal is not possible, radiation therapy and chemotherapy are used in conjunction with surgery, but with a generally low efficiency. Ongoing researches are focused on understanding the genetic and molecular basis of chondrosarcoma following high linear energy transfer (LET) irradiation, which may lead to treatments that are more effective. The goal of this study is to evaluate the differential effects of DNA damage repair inhibitors and high LET irradiation on chondrosarcoma versus chondrocyte cells and the LET-dependency of the effects. Two chondrosarcoma cell lines with different IDH mutation status and one chondrocyte cell line were exposed to low LET (X-ray) and high LET (carbon ion) irradiation in combination with an Olaparib PARP inhibitor. Cell survival and DNA repair mechanisms were investigated. High LET irradiation drastically reduced cell survival, with a biological efficiency three times that of low LET. Olaparib significantly inhibited PARylation in all the tested cells. A significant reduction in cell survival of both chondrosarcoma and chondrocyte cells was observed following the treatment combining Olaparib and X-ray. PARP inhibition induced an increase in PARP-1 expression and a reduced effect on the cell survival of WT IDH chondrosarcoma cells. No radiosensitizing effect was observed in cells exposed to Olaparib paired with high LET irradiation. NHEJ was activated in response to high LET irradiation, neutralizing the PARP inhibition effect in both chondrosarcoma cell lines. When high LET irradiation is not available, PARP inhibition could be used in combination with low LET irradiation, with significant radiosensitizing effects on chondrosarcoma cells. Chondrocytes may be affected by the treatment combination too, showing the need to preserve normal tissues from radiation fields when this kind of treatment is suggested.

Published
2024
Full Text
View/download PDF

2. In vitro hyperspectral biomarkers of human chondrosarcoma cells in nanoparticle-mediated radiosensitization using carbon ions

Author

Mihaela Tudor, Roxana Cristina Popescu, Raluca D. Negoita, Antoine Gilbert, Mihaela A. Ilisanu, Mihaela Temelie, Anca Dinischiotu, François Chevalier, Mona Mihailescu, and Diana Iulia Savu

Subjects
Medicine, Science
Abstract

Abstract New therapeutic approaches are needed for the management of the highly chemo- and radioresistant chondrosarcoma (CHS). In this work, we used polyethylene glycol-encapsulated iron oxide nanoparticles for the intracellular delivery of the chemotherapeutic doxorubicin (IONPDOX) to augment the cytotoxic effects of carbon ions in comparison to photon radiation therapy. The in vitro biological effects were investigated in SW1353 chondrosarcoma cells focusing on the following parameters: cell survival using clonogenic test, detection of micronuclei (MN) by cytokinesis blocked micronucleus assay and morphology together with spectral fingerprints of nuclei using enhanced dark-field microscopy (EDFM) assembled with a hyperspectral imaging (HI) module. The combination of IONPDOX with ion carbon or photon irradiation increased the lethal effects of irradiation alone in correlation with the induction of MN. Alterations in the hyperspectral images and spectral profiles of nuclei reflected the CHS cell biological modifications following the treatments, highlighting possible new spectroscopic markers of cancer therapy effects. These outcomes showed that the proposed combined treatment is promising in improving CHS radiotherapy.

Published
2023
Full Text
View/download PDF

3. Potential Benefits of Combining Proton or Carbon Ion Therapy with DNA Damage Repair Inhibitors

Author

Gro Elise Rødland, Mihaela Temelie, Adrian Eek Mariampillai, Sissel Hauge, Antoine Gilbert, François Chevalier, Diana I. Savu, and Randi G. Syljuåsen

Subjects
high-LET irradiation, DNA repair, DNA damage response inhibitors, antitumor immune response, radiosensitivity, Cytology, QH573-671
Abstract

The use of charged particle radiotherapy is currently increasing, but combination therapy with DNA repair inhibitors remains to be exploited in the clinic. The high-linear energy transfer (LET) radiation delivered by charged particles causes clustered DNA damage, which is particularly effective in destroying cancer cells. Whether the DNA damage response to this type of damage is different from that elicited in response to low-LET radiation, and if and how it can be targeted to increase treatment efficacy, is not fully understood. Although several preclinical studies have reported radiosensitizing effects when proton or carbon ion irradiation is combined with inhibitors of, e.g., PARP, ATR, ATM, or DNA-PKcs, further exploration is required to determine the most effective treatments. Here, we examine what is known about repair pathway choice in response to high- versus low-LET irradiation, and we discuss the effects of inhibitors of these pathways when combined with protons and carbon ions. Additionally, we explore the potential effects of DNA repair inhibitors on antitumor immune signaling upon proton and carbon ion irradiation. Due to the reduced effect on healthy tissue and better immune preservation, particle therapy may be particularly well suited for combination with DNA repair inhibitors.

Published
2024
Full Text
View/download PDF

4. Comparing Seamounts and Coral Reefs with eDNA and BRUVS Reveals Oases and Refuges on Shallow Seamounts

Author

Florian Baletaud, Gaël Lecellier, Antoine Gilbert, Laëtitia Mathon, Jean-Marie Côme, Tony Dejean, Mahé Dumas, Sylvie Fiat, and Laurent Vigliola

Subjects
conservation, biomass, biodiversity, hotspot, coral reefs, mesophotic slope, Biology (General), QH301-705.5
Abstract

Seamounts are the least known ocean biome. Considered biodiversity hotspots, biomass oases, and refuges for megafauna, large gaps exist in their real diversity relative to other ecosystems like coral reefs. Using environmental DNA metabarcoding (eDNA) and baited video (BRUVS), we compared fish assemblages across five environments of different depths: coral reefs (15 m), shallow seamounts (50 m), continental slopes (150 m), intermediate seamounts (250 m), and deep seamounts (500 m). We modeled assemblages using 12 environmental variables and found depth to be the main driver of fish diversity and biomass, although other variables like human accessibility were important. Boosted Regression Trees (BRT) revealed a strong negative effect of depth on species richness, segregating coral reefs from deep-sea environments. Surprisingly, BRT showed a hump-shaped effect of depth on fish biomass, with significantly lower biomass on coral reefs than in shallowest deep-sea environments. Biomass of large predators like sharks was three times higher on shallow seamounts (50 m) than on coral reefs. The five studied environments showed quite distinct assemblages. However, species shared between coral reefs and deeper-sea environments were dominated by highly mobile large predators. Our results suggest that seamounts are no diversity hotspots for fish. However, we show that shallower seamounts form biomass oases and refuges for threatened megafauna, suggesting that priority should be given to their protection.

Published
2023
Full Text
View/download PDF

5. Label-Free Direct Mass Spectrometry Analysis of the Bystander Effects Induced in Chondrocytes by Chondrosarcoma Cells Irradiated with X-rays and Carbon Ions

Author

Antoine Gilbert, Valentin Payet, Benoît Bernay, Elisabeth Chartier-Garcia, Isabelle Testard, Serge M. Candéias, and François Chevalier

Subjects
bystander effect, carbon irradiation, chondrosarcoma, proteomic analysis, stress granules, il12, Biochemistry, QD415-436, Biology (General), QH301-705.5
Abstract

Background: Radiation-induced bystander effects are induced changes in cells that were not themselves directly irradiated but were in the vicinity of a radiation path. Such effects, which occur in the microenvironment of an irradiated tumor, remain poorly understood and depend on the cell type and irradiation quality. This study aimed to evaluate bystander effects in non-irradiated chondrocytes that received conditioned medium from irradiated chondrosarcoma cells. Methods: SW1353 chondrosarcoma cells were irradiated with X-rays and carbon ions, each at 0.1 Gy and 2 Gy, and the conditioned media of the irradiated cells were transferred to T/C-28A2 chondrocytes and Human Umbilical Venous Endothelial Cells (HUVECs). The whole proteome of bystander chondrocytes was analyzed by label-free mass spectrometry, and a comparative study was performed by dose and irradiation quality. HUVECs were evaluated for inflammatory cytokine secretion. Results: The bystander response of chondrocytes to X-ray irradiation primarily affected the protein translation pathway (DHX36, EIF3B, EIF3D, EIF3M, EIF5, RPL6, RPLP0, RPS24, SYNCRIP), IL-12 (AIP, BOLA2, MIF, GAS6, MIF, PDGFRB) and the oxidative stress pathway (MGST3, PRDX2, PXDN, SOD2, TXN, TXNL1). Following carbon-ion irradiation, the G1/S pathway (PCBP4, PSMD12, PSME, XIAP) and mitotic G2 DNA damage checkpoint pathway (MRE11, TAOK1, UIMC1) were engaged. Changes in the regulation of chromosome separation (BCL7C, BUB3, CENPF, DYNC1LI1, SMARCA4, SMC4) were associated with only low-dose X-ray and carbon-ion irradiation. Modification of the protein translation pathway represented at least 30% of bystander effects and could play a role, possibly along with stress granules, in reduction in cellular metabolism to protect proteins. Stress granules were significantly enriched according to an interaction map. Conclusions: All these accessions corresponded to a window of the proteins modulated in response to the bystander effect. Our chondrosarcoma model clarified the nature of the bystander response of chondrocytes and may suggest several interesting new mechanisms that are specific to particular irradiation doses and qualities.

Published
2022
Full Text
View/download PDF

7. Growth, Survival and Reproduction of the Giant Clam Tridacna maxima (Röding 1798, Bivalvia) in Two Contrasting Lagoons in French Polynesia.

Author

Simon Van Wynsberge, Serge Andréfouët, Nabila Gaertner-Mazouni, Colette C C Wabnitz, Mathilde Menoud, Gilles Le Moullac, Peva Levy, Antoine Gilbert, and Georges Remoissenet

Subjects
Medicine, Science
Abstract

Shell growth, reproduction, and natural mortality of the giant clam Tridacna maxima were characterized over a two-year-period in the lagoon of the high island of Tubuai (Austral Archipelago) and in the semi-closed lagoon of Tatakoto (Tuamotu Archipelago) in French Polynesia. We also recorded temperature, water level, tidal slope, tidal range, and mean wave height in both lagoons. Lower lagoon aperture and exposure to oceanic swells at Tatakoto than at Tubuai was responsible for lower lagoon water renewal, as well as higher variability in temperature and water level at Tatakoto across the studied period. These different environmental conditions had an impact on giant clams. Firstly, spawning events in the lagoon of Tatakoto, detected by gonad maturity indices in June and July 2014, were timed with high oceanic water inflow and a decrease in lagoon water temperature. Secondly, temperature explained differences in shell growth rates between seasons and lagoons, generating different growth curves for the two sites. Thirdly, local mortality rates were also found to likely be related to water renewal patterns. In conclusion, our study suggests that reef aperture and lagoon water renewal rates play an integral role in giant clam life history, with significant differences in rates of shell growth, mortality and fertility found between open versus semi-closed atoll lagoons in coral reef ecosystems.

Published
2017
Full Text
View/download PDF

8. Best management strategies for sustainable giant clam fishery in French Polynesia islands: answers from a spatial modeling approach.

Author

Simon Van Wynsberge, Serge Andréfouët, Antoine Gilbert, Arsène Stein, and Georges Remoissenet

Subjects
Medicine, Science
Abstract

The giant clam Tridacna maxima has been largely overexploited in many tropical regions over the past decades, and was therefore listed in appendix II of the Convention of International Trade in Endangered Species (CITES) in 1985. In French Polynesia, several atolls and islands harbor the world's highest stocks of giant clams in very shallow and accessible areas, which are therefore highly vulnerable to fishing pressure. The local fishery authority (i.e., Direction des Resources Marines or "DRM") implemented several management schemes in 2002 to control and regulate fishing pressure. However, for further decisions DRM was missing a sensitivity analysis on the effectiveness of the possible management actions. Here, we report on the use of a deterministic Viable Population Analysis (VPA) and spatially-explicit age-based population model that simulated the 30-year trajectory of a Tridacna maxima stock under different management approaches. Specifically, given various scenarios of intra-island larval dispersal, we tested which of No-take-Areas (NTAs), rotational closures, size limits, quotas, and restocking schemes would lead to the highest future stocks in Tubuai and Raivavae, two exploited islands of the Austral archipelago. For both islands, stock abundances were estimated in 2004/2010 and 2005/2010 respectively, and natural mortalities were assessed previously only in Tubuai. When compared to field data, the model successfully predicted the 2010 stocks for Tubuai, but proved to be less reliable for Raivavae, where natural mortality rates may well be different from those on Tubuai. For Tubuai, the spatial model suggested that reducing fishing effort (through fixed quotas) and banning fishing below the 12 cm size limit (as currently implemented) were the most effective management actions to sustain T. maxima populations into the future. Implementing NTAs was of poor effectiveness. NTAs increased giant clam stock inside the protected area, but also increased overfishing in the neighboring areas, and were ineffective overall.

Published
2013
Full Text
View/download PDF

9. A Proteomic Study Suggests Stress Granules as New Potential Actors in Radiation-Induced Bystander Effects

Author

François Chevalier, Jean Armengaud, Sonia Hem, Mihaela Tudor, Charlotte Lepleux, Diana Savu, Antoine Gilbert, Siamak Haghdoost, Emilie Brotin, Mihaela Temelie, Horia Hulubei National Institute of Physics and Nuclear Engineering (NIPNE), IFIN-HH, University of Bucharest (UniBuc), Accueil et Recherche en Radiobiologie des Ions Accélérés (ARIA), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU), Biochimie et Physiologie Moléculaire des Plantes (BPMP), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre Régional de Lutte contre le Cancer François Baclesse [Caen] (UNICANCER/CRLC), UNICANCER-Tumorothèque de Caen Basse-Normandie (TCBN)-Normandie Université (NU), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Normandie Université (NU)-UNICANCER-Tumorothèque de Caen Basse-Normandie (TCBN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Proteomics, 0301 basic medicine, stress granules, DNA damage, QH301-705.5, Bone Neoplasms, Radiation induced, [SDV.CAN]Life Sciences [q-bio]/Cancer, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Cytoplasmic Granules, medicine.disease_cause, Article, Catalysis, Inorganic Chemistry, 03 medical and health sciences, Chondrocytes, 0302 clinical medicine, Stress granule, Western blot, Cell Line, Tumor, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], bystander signaling, Conditioned medium, Bystander effect, medicine, Humans, Physical and Theoretical Chemistry, Biology (General), Molecular Biology, QD1-999, Spectroscopy, chondrosarcoma, medicine.diagnostic_test, Chemistry, X-Rays, Organic Chemistry, Bystander Effect, General Medicine, proteomic analysis, Microvesicles, Computer Science Applications, Cell biology, secretome, 030104 developmental biology, 030220 oncology & carcinogenesis, [PHYS.PHYS.PHYS-MED-PH]Physics [physics]/Physics [physics]/Medical Physics [physics.med-ph], Oxidative stress
Abstract

Besides the direct effects of radiations, indirect effects are observed within the surrounding non-irradiated area, irradiated cells relay stress signals in this close proximity, inducing the so-called radiation-induced bystander effect. These signals received by neighboring unirradiated cells induce specific responses similar with those of direct irradiated cells. To understand the cellular response of bystander cells, we performed a 2D gel-based proteomic study of the chondrocytes receiving the conditioned medium of low-dose irradiated chondrosarcoma cells. The conditioned medium was directly analyzed by mass spectrometry in order to identify candidate bystander factors involved in the signal transmission. The proteomic analysis of the bystander chondrocytes highlighted 20 proteins spots that were significantly modified at low dose, implicating several cellular mechanisms, such as oxidative stress responses, cellular motility, and exosomes pathways. In addition, the secretomic analysis revealed that the abundance of 40 proteins in the conditioned medium of 0.1 Gy irradiated chondrosarcoma cells was significantly modified, as compared with the conditioned medium of non-irradiated cells. A large cluster of proteins involved in stress granules and several proteins involved in the cellular response to DNA damage stimuli were increased in the 0.1 Gy condition. Several of these candidates and cellular mechanisms were confirmed by functional analysis, such as 8-oxodG quantification, western blot, and wound-healing migration tests. Taken together, these results shed new lights on the complexity of the radiation-induced bystander effects and the large variety of the cellular and molecular mechanisms involved, including the identification of a new potential actor, namely the stress granules.

Published
2021
Full Text
View/download PDF

10. Assembly rules of fish communities in Tuamotu archipelago atoll lagoons : the case of Fangatau, a lagoon dominated by giant clam habitats

Author

Gérard Mou-Tham, Serge Andréfouët, Antoine Gilbert, Jonas Tuahine, and Michel Kulbicki

Subjects
0106 biological sciences, Assembly rules, Coral reef fish, Population, Atoll, Pomacentridae, Aquatic Science, Oceanography, 010603 evolutionary biology, 01 natural sciences, education, Ecology, Evolution, Behavior and Systematics, geography, education.field_of_study, geography.geographical_feature_category, Pacific Ocean, Functional and taxonomic diversity, biology, Ecology, 010604 marine biology & hydrobiology, Giant clam, Geomorphology, biology.organism_classification, Acanthuridae, Fishery, Tridacna maxima, Species richness
Abstract

Assembly rules of fish communities in Tuamotu Archipelago lagoons have been previously investigated but without considering lagoons where shallow habitats are dominated by giant clam populations. We tested if assembly rules for 14 atolls were challenged by such an atoll (Fangatau), and in doing so investigated the robustness of inter-island population patterns to specialized habitats. Fangatau had significantly higher proportions of Pomacentridae and Scaridae, but lower proportions of Labridae, Acanthuridae, Balistidae and Serranidae. Functionally, herbivores, omnivores, species

Published
2018

11. Growth, survival and reproduction of the giant clam Tridacna maxima (Röding 1798, Bivalvia) in two contrasting lagoons in French Polynesia

Author

Nabila Gaertner-Mazouni, Mathilde Menoud, Georges Remoissenet, Peva Levy, Colette C. C. Wabnitz, Gilles Le Moullac, Antoine Gilbert, Simon Van Wynsberge, Serge Andréfouët, Ecologie marine tropicale des océans Pacifique et Indien (ENTROPIE [Nouvelle-Calédonie]), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Ifremer - Nouvelle-Calédonie, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Nouvelle-Calédonie (UNC), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie]), Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD), Secretariat of the Pacific Community, Écosystémique des communautés récifales et de leurs usages dans le Pacifique insulaire (CoReUS), Direction des Ressources Marines et Minières, Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), and Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)

Subjects
0106 biological sciences, Male, Topography, Atoll, lcsh:Medicine, Marine and Aquatic Sciences, Juvenile, French Polynesia, Wind, 01 natural sciences, Mass mortality, Medicine and Health Sciences, Giant Clam, lcsh:Science, Archipelago, Islands, Multidisciplinary, geography.geographical_feature_category, biology, Coral Reefs, Reproduction, [SDV.BA]Life Sciences [q-bio]/Animal biology, Temperature, Coral reef, Population-size, Female, Seasons, Anatomy, Genital Anatomy, Research Article, Lagoons, Bivalves, Tidal range, Death Rates, Marine Biology, 010603 evolutionary biology, Polynesia, Animal Shells, Water Movements, Animals, Seawater, Atolls, 14. Life underwater, Gonads, Reef, Ecosystem, Demography, geography, Landforms, 010604 marine biology & hydrobiology, lcsh:R, Communities, Giant clam, Reproductive System, Organisms, Biology and Life Sciences, Geomorphology, Molluscs, Bodies of Water, Bivalvia, biology.organism_classification, Survival Analysis, Invertebrates, Eastern Tuamotu, Water level, Fishery, Tridacna maxima, Fertility, People and Places, Earth Sciences, Reefs, lcsh:Q
Abstract

International audience; Shell growth, reproduction, and natural mortality of the giant clam Tridacna maxima were characterized over a two-year-period in the lagoon of the high island of Tubuai (Austral Archipelago) and in the semi-closed lagoon of Tatakoto (Tuamotu Archipelago) in French Polynesia. We also recorded temperature, water level, tidal slope, tidal range, and mean wave height in both lagoons. Lower lagoon aperture and exposure to oceanic swells at Tata-koto than at Tubuai was responsible for lower lagoon water renewal, as well as higher variability in temperature and water level at Tatakoto across the studied period. These different environmental conditions had an impact on giant clams. Firstly, spawning events in the lagoon of Tatakoto, detected by gonad maturity indices in June and July 2014, were timed with high oceanic water inflow and a decrease in lagoon water temperature. Secondly, temperature explained differences in shell growth rates between seasons and lagoons, generating different growth curves for the two sites. Thirdly, local mortality rates were also found to likely be related to water renewal patterns. In conclusion, our study suggests that reef aperture and lagoon water renewal rates play an integral role in giant clam life history, with significant differences in rates of shell growth, mortality and fertility found between open versus semi-closed atoll lagoons in coral reef ecosystems.

Published
2017
Full Text
View/download PDF

12. Nickel and ocean warming affect scleractinian coral growth

Author

Anne Lorrain, A. Wright, T. Biscere, C. Devissi, Antoine Gilbert, Fanny Houlbrèque, R. Farman, Riccardo Rodolfo-Metalpa, Christophe Peignon, Claude Payri, E. Duvieilbourg, Ecologie marine tropicale des océans Pacifique et Indien (ENTROPIE [Nouvelle-Calédonie]), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Ifremer - Nouvelle-Calédonie, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Nouvelle-Calédonie (UNC), Institut de Recherche pour le Développement (IRD), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie]), Ifremer - Nouvelle-Calédonie, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Université de la Nouvelle-Calédonie (UNC), Institut Universitaire Européen de la Mer (IUEM), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO)

Subjects
0106 biological sciences, Effects of global warming on oceans, 010501 environmental sciences, Oceanography, 01 natural sciences, calcification, Symbiodinium, Nickel, trace-metals, heavy-metals, Water Pollutants, Photosynthesis, Global change, Coral Reefs, marine diatom, Anthozoa, Pollution, Benthic zone, Metals, Coral bleaching, climate-change, Dinoflagellida, Coral photosynthesis, Oceans and Seas, Fringing reef, chemistry.chemical_element, Pocillopora damicornis, Aquatic Science, Biology, Animals, Ecosystem, reef, 14. Life underwater, stylophora-pistillata, global change, 0105 earth and related environmental sciences, Coral growth, ACL, 010604 marine biology & hydrobiology, fungi, fertilization success, biology.organism_classification, chemistry, 13. Climate action, copper, new-caledonia lagoon, [SDE.BE]Environmental Sciences/Biodiversity and Ecology
Abstract

WOS:000407539300039; International audience; The sensitivity of corals and their Symbiodinium to warming has been extensively documented; however very few studies considered that anthropogenic inputs such as metal pollution have already an impact on many fringing reefs. Thus, today, nickel releases are common in coastal ecosystems. In this study, two major reef-building species Acropora muricata and Pocillopora damicornis were exposed in situ to ambient and moderate nickel concentrations on a short-term period (1 h) using benthic chamber experiments. Simultaneously, we tested in laboratory conditions the combined effects of a chronic exposure (8 weeks) to moderate nickel concentrations and ocean warming on A. muricata. The in situ experiment highlighted that nickel enrichment, at ambient temperature, stimulated by 27 to 47% the calcification rates of both species but not their photosynthetic performances. In contrast, an exposure to higher nickel concentration, in combination with elevated temperature simulated in aquaria, severely depressed by 30% the growth of A. muricata.

Published
2017
Full Text
View/download PDF

13. Drivers of density for the exploited giant clam Tridacna maxima : a meta-analysis

Author

Georges Remoissenet, Serge Andréfouët, Antoine Gilbert, Claude Payri, Nabila Gaertner-Mazouni, Colette C. C. Wabnitz, Cécile Fauvelot, Simon Van Wynsberge, Coreus, Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie]), Institut de recherche pour le développement (IRD [Sénégal]), Ecosystèmes Insulaires Océaniens (UMR 241) (EIO), Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), Institut de Recherche pour le Développement (IRD)-Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Écosystémique des communautés récifales et de leurs usages dans le Pacifique insulaire (CoReUS), Direction des Ressources Marines et Minières, Systématique, adaptation, évolution (SAE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Polynésie Française (UPF)-Institut Louis Malardé [Papeete] (ILM), and Institut de Recherche pour le Développement (IRD)

Subjects
0106 biological sciences, [SDV]Life Sciences [q-bio], Population, Atoll, [SDV.BID]Life Sciences [q-bio]/Biodiversity, Management, Monitoring, Policy and Law, Aquatic Science, Oceanography, 010603 evolutionary biology, 01 natural sciences, tridacninae, fishery management, Tridacninae, 14. Life underwater, education, Reef, Ecology, Evolution, Behavior and Systematics, overfishing, geography, education.field_of_study, geography.geographical_feature_category, biology, Overfishing, giant clam population dynamics, 010604 marine biology & hydrobiology, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], Giant clam, biology.organism_classification, Tridacna, Fishery, Tridacna maxima, Habitat
Abstract

International audience; Giant clam populations have been over-exploited throughout their range over the past decades for their meat and shells. Tridacna maxima, commonly known as the ‘small giant clam’, has remained relatively untargeted by fishers in areas where larger species occur (e.g. Tridacna squamosa), and high densities of the species are still observed on some isolated and enclosed reefs of the Central Pacific. However, it is unclear whether reported discrepancies in densities worldwide reflect differences in fishing pressure only or a combination of differences in exploitation levels and environmental forcing. We reviewed T. maxima surveys throughout its range to (i) identify patterns of density at global scale, site scale (e.g. island) and intrasite scale; (ii) discuss the influence of sampling method on density estimates; and (iii) identify the primary drivers of giant clam density along gradients of human pressure and natural forcing. We found 59 studies that reported density estimates for 172 sites across 26 countries in the Indo-Pacific and Red Sea. At intrasite scale, densities were strongly dependent on sampling protocols and surveyed habitats. At site scale, we found close links between T. maxima density and human population per reef area, suggesting that isolated reefs where exploitation only recently started may be more vulnerable to stock collapse in the future. Density patterns were also found to vary significantly depending on reef type (e.g. atoll, island, continental coastline). We discuss how natural processes and fishing pressure may control population dynamics and densities among sites, and make recommendations for future research.

Published
2016
Full Text
View/download PDF

14. Endangered New Caledonian endemic mushroom coral Cantharellus noumeae in turbid, metal-rich, natural and artificial environments

Author

Cécile Fauvelot, Serge Andréfouët, Francesca Benzoni, Antoine Gilbert, Tom Heintz, Bert W. Hoeksema, Jean Michel Fernandez, Gilbert, A, Heintz, T, Hoeksema, B, Benzoni, F, Fernandez, J, Fauvelot, C, Andréfouët, S, Naturalis Biodiversity Center [Leiden], Università degli Studi di Milano-Bicocca [Milano] (UNIMIB), Ecologie marine tropicale des océans Pacifique et Indien (ENTROPIE [Nouvelle-Calédonie]), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Ifremer - Nouvelle-Calédonie, and Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Nouvelle-Calédonie (UNC)

Subjects
IUCN Red-List, Coral, Endangered species, Fungiidae, Aquatic Science, Oceanography, New Caledonia, Anthozoa, IUCN Red List, Animals, 14. Life underwater, ComputingMilieux_MISCELLANEOUS, Ecosystem, Cantharellus, UNESCO World Heritage, biology, Ecology, Endangered Species, biology.organism_classification, Pollution, Coral community, Nickel mining, Bays, Metals, Conservation status, Sediment, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Agaricales, Bay, BIO/05 - ZOOLOGIA
Abstract

Since its description in 1984, little attention has been paid to the New Caledonian endemic mushroom coral Cantharellus noumeae (Fungiidae), an IUCN Red-listed, endangered coral species. Our study presents the first ever quantitative assessment conducted on C. noumeae populations for two contrasting sites in the same turbid bay. Sites differed by their substrates of artificial or natural origins. Metal concentrations of superficial sediment were measured. C. noumeae was found in high densities in metal-rich and turbid environments at both locations, reaching up to 288 individuals per 50m(2). It was 3.5 times more abundant on natural rock than on artificial substrates. Recruitment was also higher proportionally on rock (47% vs 7-14%). The composition of the associated coral communities included 30-37 species occurring in low densities. Our findings clarify the environmental niche of this species and its colonization potential, in order to eventually better characterize its conservation status.

Published
2015
Full Text
View/download PDF

15. Climate variability and massive mortalities challenge giant clam conservation and management efforts in French Polynesia atolls

Author

Georges Remoissenet, Christophe E. Menkès, Simon Van Wynsberge, Antoine Gilbert, Nabila Gaertner-Mazouni, Serge Andréfouët, Coreus, Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie]), BIOTEM, Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL)

Subjects
0106 biological sciences, Stock assessment, Community-based management, Population, Atoll, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Bottom-up conservation, 010603 evolutionary biology, 01 natural sciences, Fisheries management, 14. Life underwater, education, Transect, Tuamotu archipelago, Ecology, Evolution, Behavior and Systematics, ComputingMilieux_MISCELLANEOUS, Nature and Landscape Conservation, geography, education.field_of_study, geography.geographical_feature_category, biology, 010604 marine biology & hydrobiology, Giant clam, biology.organism_classification, Fishery, Tridacna maxima, Sea surface temperature, CITES, Top-down conservation
Abstract

In 2004, the first no-take area (NTA) dedicated to the conservation of giant clams Tridacna maxima was implemented in Tatakoto Atoll, French Polynesia. This NTA protected a unique area worldwide, with extraordinarily high giant clam densities (up to 337 individuals per m2 on 20-m transect). In 2012, a stock assessment survey revealed a dramatic decrease of the clam population. The reduced densities peaked at 38 ind m−2 and the stock in the NTA decreased from 20.1 ± 6.0 million to 1.9 ± 0.55 million clams (mean ± 95% confidence interval). Losses of similar proportions were observed throughout the atoll. Remarkably, the 83% overall loss of this natural resource used daily for consumption and for exports of clam meat to Tahiti Island went unnoticed by the local population. Field clues, including the size of live juveniles attached to the inside of dead shells, pointed to a massive mortality occurring about 3 years before the 2012 survey. Examinations of sea surface temperature satellite data identified a high range of temperature variations before March 2009. In agreement with past and recent events in other atolls, this anomaly is the most likely explanation of the massive loss of giant clams in Tatakoto Atoll, although the exact hydrological and biological secondary mechanisms that occurred in the lagoon remain unclear. The consequences of the massive die-off inside and outside the NTA require new long-term management strategies, by reinforcing the top-down national giant clam management arrangements and by setting flexible management objectives across a network of islands.

Published
2013
Full Text
View/download PDF

16. First observation of the giant clam Tridacna squamosa in French Polynesia : a species range extension

Author

Serge Andréfouët, Antoine Gilbert, Serge Planes, Georges Remoissenet, Kim Friedman, Institut de Recherche pour le Développement (IRD [Polynésie]), Centre de recherches insulaires et observatoire de l'environnement (CRIOBE), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), École pratique des hautes études (EPHE), PROCFish Coastal Fisheries Programme, and Service de la Pêche

Subjects
0106 biological sciences, geography, geography.geographical_feature_category, biology, 010604 marine biology & hydrobiology, [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE], Species distribution, Giant clam, Coral reef, Aquatic Science, biology.organism_classification, Bivalvia, 010603 evolutionary biology, 01 natural sciences, Tridacna, Fishery, Oceanography, Mollusca
Published
2007
Full Text
View/download PDF

17. The remarkable population size of the endangered clam Tridacna maxima assessed in Fangatau Atoll (Eastern Tuamotu, French Polynesia) using in situ and remote sensing data

Author

Serge Andréfouët, Laurent Yan, Antoine Gilbert, Georges Remoissenet, Yannick Chancerelle, and Claude Payri

Subjects
geography, education.field_of_study, geography.geographical_feature_category, Ecology, biology, Population size, Population, Endangered species, Giant clam, Atoll, Coral reef, Aquatic Science, Oceanography, biology.organism_classification, Fishery, Habitat, Environmental science, education, Reef, Ecology, Evolution, Behavior and Systematics, Remote sensing
Abstract

Several lagoons of the Eastern Tuamotu Atolls (French Polynesia) are characterized by enormous populations of the clam Tridacna maxima, a species considered as endangered in many locations worldwide. This unique resource is virtually intact, until recently being impacted only by local consumption. Increasing exports to Tahiti's market (up to 50 tonnes of wet matter y−1), combined with the relatively small size of these lagoons (

Published
2005

Catalog

Books, media, physical & digital resources
See catalog results