Gauthier SCHAAL

Biologie et écologie marine, écologie trophique, isotopes stables, acides gras

Maître de Conférences
Université de Bretagne Occidentale

Affectation

Laboratoire LEMAR

Discovery

Contact

Je suis enseignant-chercheur à l’Université de Bretagne Occidentale depuis 2012, après une thèse réalisée à la Station Biologique de Roscoff (Sorbonne Universités), et un post-doctorat en Afrique du Sud, à Rhodes University (Grahamstown).

Mon activité de recherche s’intéresse à la compréhension des interactions trophiques au sein des écosystèmes, depuis les consommateurs primaires benthiques jusqu’aux grand prédateurs pélagiques. J’utilise pour cela différentes approches, et en particulier celles basées sur les biomarqueurs trophiques que sont les isotopes stables (C, N, S, Hg), les lipides (acides gras, stérols) ou les éléments trace métalliques. Mon activité m’amène également à m’intéresser à d’autres aspects du fonctionnement des écosystèmes, comme la structure et la composition des communautés, en lien avec un goût personnel marqué pour la taxonomie des invertébrés benthiques.

Mes principales zones géographiques d’intérêt sont les milieux côtiers de l’Europe Occidentale, Les lagunes méditerranéennes, la côte Pacifique du Mexique (Basse Californie), le Gabon et Mayotte.

 

Je co-encadre actuellement les thèses de:

Rémi Brosse: Facteurs influençant la distribution du gastéropode Terebralia palustris dans les mangroves de Mayotte (co-encadrement avec Claire Golléty, CUFR Mayotte)

Sandrine Serre: Fréquentation des côtes du Tregor par le requin-taupe Lamna nasus (co-encadrement avec François Le Loc’h, IRD, et Eric Stéphan, Association pour l’Etude et la Conservation des Sélaciens)

Youri Ivann Mvomo Minko: Rôle fonctionnel des eaux côtières du Gabon pour deux espèces de requin, Sphyrna lewini et Carcharhinus limbatus (co-encadrement avec François Le Loc’h, IRD, et Jean-Daniel Mbega, IRT CEBAREST, Gabon)

Anthony Voisin: La biodiversité dans un environnement en rapide évolution: structure des communautés, interactions trophiques et réponses fonctionnelles dans un écosystèmes benthique antarctique (co-encadrement avec Julien Thébault, UBO, et Gilles Lepoint, Université de Liège, Belgique)

 

Anciennes thèses encadrées

Lucien Besnard: Ecologie trophique des requins pélagiques des côtes de Basse Californie (Mexique) (co-encadrement avec Edouard Kraffe, UBO, et Raúl Martínez-Rincón, CIBNOR, Mexique)

Anthony Sturbois: Habitats benthiques, fonction de nourricerie et dynamique trophique de la Baie de Saint-Brieuc (co-encadrement avec Nicolas Desroy, Ifremer)

Thomas Burel: Effet de l’hydrodynamisme sur la structure des communautés macroalgales et sur les interactions macroflore / macrofaune en zone intertidale (co-encadrement avec Erwan Ar Gall et Jacques Grall, UBO)

Margaux Mathieu-Resuge: Ecophysiologie trophique des bivalves Nodipecten subnodosus et Spondylus crassisquama soumis à la variabilité environnementale dans la lagune d’Ojo de Liebre (Basse Californie, Mexique) (co-encadrement avec Edouard Kraffe, UBO)

 

Le Croizier, G., Lorrain, A., Hoyos-Padilla, M., Ketchum, J. T., Amezcua-Martinez, F., Le Loc’h, F., Munaron, J.-M., Schaal, G., & Point, D. (2023). Do marine protected areas influence mercury exposure? Insights from a shark community in the tropical Northeast Pacific. ENVIRONMENTAL POLLUTION, 336, 122352. https://doi.org/10.1016/j.envpol.2023.122352 Cite
Besnard, L., Lucca, B. M. M., Shipley, O. N. N., Le Croizier, G., Martinez-Rincon, R. O., Sonke, J. E. E., Point, D., Galvan-Magana, F., Kraffe, E., Kwon, S. Y., & Schaal, G. (2023). Mercury isotope clocks predict coastal residency and migration timing of hammerhead sharks. Journal of Applied Ecology. https://doi.org/10.1111/1365-2664.14384 Cite
Sturbois, A., Cozic, A., Schaal, G., Desroy, N., Riera, P., Le Pape, O., Le Mao, P., Ponsero, A., & Carpentier, A. (2022). Stomach content and stable isotope analyses provide complementary insights into the trophic ecology of coastal temperate bentho-demersal assemblages under environmental and anthropogenic pressures. Marine Environmental Research, 182, 105770. https://doi.org/10.1016/j.marenvres.2022.105770 Cite
Burel, T., Schaal, G., Grall, J., Le Duff, M., & Gall, E. A. (2022). Clear-cut wave height thresholds reveal dominance shifts in assemblage patterns on rocky shores. Marine Ecology Progress Series, 683, 21–36. https://doi.org/10.3354/meps13945 Cite
Besnard, L., Duchatelet, L., Bird, C. S., Le Croizier, G., Michel, L., Pinte, N., Lepoint, G., Schaal, G., Vieira, R. P., Goncalves, J. M. S., Martin, U., & Mallefet, J. (2022). Diet consistency but large-scale isotopic variations in a deep-sea shark: The case of the velvet belly lantern shark, Etmopterus spinax, in the northeastern Atlantic region and Mediterranean Sea. Deep-Sea Research Part I-Oceanographic Research Papers, 182, 103708. https://doi.org/10.1016/j.dsr.2022.103708 Cite
Sturbois, A., Riera, P., Desroy, N., Brebant, T., Carpentier, A., Ponsero, A., & Schaal, G. (2022). Spatio-temporal patterns in stable isotope composition of a benthic intertidal food web reveal limited influence from salt marsh vegetation and green tide. Marine Environmental Research, 175, 105572. https://doi.org/10.1016/j.marenvres.2022.105572 Cite
Burel, T., Schaal, G., Grall, J., Le Duff, M., Chapalain, G., Schmitt, B., Gemin, M., Boucher, O., & Ar Gall, E. (2019). Small-scale effects of hydrodynamics on the structure of intertidal macroalgal communities: A novel approach. Estuarine Coastal and Shelf Science, 226, UNSP 106290. https://doi.org/10.1016/j.ecss.2019.106290 Cite
Sturbois, A., Cucherousset, J., De Cáceres, M., Desroy, N., Riera, P., Carpentier, A., Quillien, N., Grall, J., Espinasse, B., Cherel, Y., & Schaal, G. (2022). Stable Isotope Trajectory Analysis (SITA): A new approach to quantify and visualize dynamics in stable isotope studies. Ecological Monographs. https://doi.org/10.1002/ecm.1501 Cite
Sturbois, A., Cormy, G., Schaal, G., Gauthier, O., Ponsero, A., Le Mao, P., Riera, P., & Desroy, N. (2021). Characterizing spatio-temporal changes in benthic communities: Taxonomic and functional trajectories of intertidal assemblages in the bay of Saint-Brieuc (English Channel). Estuarine Coastal and Shelf Science, 262, 107603. https://doi.org/10.1016/j.ecss.2021.107603 Cite
Masia, P., Mateo, J. L., Arias, A., Bartolome, M., Blanco, C., Erzini, K., Le Loc’h, F., Mve Beh, J. H., Power, D., Rodriguez, N., Schaal, G., Machado-Schiaffino, G., & Garcia-Vazquez, E. (2022). Potential microplastics impacts on African fishing resources. Science of the Total Environment, 806, 150671. https://doi.org/10.1016/j.scitotenv.2021.150671 Cite
Sturbois, A., Cormy, G., Le Moal, A., Schaal, G., Broudin, C., Thiebaut, E., Ponsero, A., Le Mao, P., Jones, A., Riera, P., Gauthier, O., & Desroy, N. (2021). Using ecological trajectories to track long-term taxonomic and functional changes in benthic shallow soft-bottom communities (Bay of Saint-Brieuc, English Channel). Aquatic Conservation-Marine and Freshwater Ecosystems. https://doi.org/10.1002/aqc.3704 Cite
Besnard, L., Le Croizier, G., Galvan-Magana, F., Point, D., Kraffe, E., Ketchum, J., Martinez Rincon, R. O., & Schaal, G. (2021). Foraging depth depicts resource partitioning and contamination level in a pelagic shark assemblage: Insights from mercury stable isotopes. Environmental Pollution, 283, 117066. https://doi.org/10.1016/j.envpol.2021.117066 Cite
Burel, T., Grall, J., Schaal, G., Le Duff, M., & Ar Gall, E. (2020). Wave height vs. elevation effect on macroalgal dominated shores: an intercommunity study. Journal of Applied Phycology, 32(4), 2523–2534. https://doi.org/10.1007/s10811-019-01989-1 Cite
Mathieu-Resuge, M., Le Grand, F., Schaal, G., Lluch-Cota, S. E., Racotta, I. S., & Kraffe, E. (2020). Specific regulations of gill membrane fatty acids in response to environmental variability reveal fitness differences between two suspension-feeding bivalves (Nodipecten subnodosus and Spondylus crassisquama). Conservation Physiology, 8, coaa079. https://archimer.ifremer.fr/doc/00648/75991/. https://doi.org/10.1093/conphys/coaa079 Cite
Le Croizier, G., Lorrain, A., Schaal, G., Ketchum, J., Hoyos-Padilla, M., Besnard, L., Munaron, J.-M., Le Loc’h, F., & Point, D. (2020). Trophic resources and mercury exposure of two silvertip shark populations in the Northeast Pacific Ocean. Chemosphere, 253, 126645. https://doi.org/10.1016/j.chemosphere.2020.126645 Cite
Le Croizier, G., Lorrain, A., Sonke, J. E., Jaquemet, S., Schaal, G., Renedo, M., Besnard, L., Cherel, Y., & Point, D. (2020). Mercury isotopes as tracers of ecology and metabolism in two sympatric shark species. Environmental Pollution, 265(PT B), 114931. https://doi.org/10.1016/j.envpol.2020.114931 Cite
Jones, A. G., Quillien, N., Fabvre, A., Grall, J., Schaal, G., & Le Bris, H. (2020). Green macroalgae blooms (Ulva spp.) influence trophic ecology of juvenile flatfish differently in sandy beach nurseries. Marine Environmental Research, 154, UNSP 104843. https://doi.org/10.1016/j.marenvres.2019.104843 Cite
Mathieu-Resuge, M., Le Grand, F., Schaal, G., Kraffe, E., Lorrain, A., Letourneur, Y., Lemonnier, H., Benoit, J., & Hochard, S. (2020). Assimilation of shrimp farm sediment by Holothuria scabra: a coupled fatty acid and stable isotope approach. Aquatic Living Resources, 33, 3. https://archimer.ifremer.fr/doc/00624/73589/. https://doi.org/10.1051/alr/2020004 Cite
Le Croizier, G., Lorrain, A., Sonke, J. E., Hoyos-Padilla, E. M., Galvan-Magana, F., Santana-Morales, O., Aquino-Baleyto, M., Becerril-Garcia, E. E., Muntaner-Lopez, G., Ketchum, J., Block, B., Carlisle, A., Jorgensen, S. J., Besnard, L., Jung, A., Schaal, G., & Point, D. (2020). The Twilight Zone as a Major Foraging Habitat and Mercury Source for the Great White Shark. Environmental Science & Technology, 54(24), 15872–15882. https://doi.org/10.1021/acs.est.0c05621 Cite
Sturbois, A., De Caceres, M., Sanchez-Pinillos, M., Schaal, G., Gauthier, O., Le Mao, P., Ponsero, A., & Desroy, N. (2021). Extending community trajectory analysis: New metrics and representation. Ecological Modelling, 440, 109400. https://doi.org/10.1016/j.ecolmodel.2020.109400 Cite
Le Croizier, G., Schaal, G., Point, D., Le Loc’h, F., Machu, E., Fall, M., Munaron, J.-M., Boye, A., Walter, P., Lae, R., & Tito-de-Morais, L. (2019). Stable isotope analyses revealed the influence of foraging habitat on mercury accumulation in tropical coastal marine fish. Science of the Total Environment, 650, 2129–2140. fdi:010074333 ;  https://archimer.ifremer.fr/doc/00458/57013/. https://doi.org/10.1016/j.scitotenv.2018.09.330 Cite
Mathieu-Resuge, M., Kraffe, E., Le Grand, F., Boens, A., Bideau, A., Lluch-Cota, S. E., Racotta, I. S., & Schaal, G. (2019). Trophic ecology of suspension-feeding bivalves inhabiting a north-eastern Pacific coastal lagoon: Comparison of different biomarkers. Marine Environmental Research, 145, 155–163. https://archimer.ifremer.fr/doc/00484/59521/. https://doi.org/10.1016/j.marenvres.2019.02.016 Cite
Mathieu-Resuge, M., Schaal, G., Kraffe, E., Corvaisier, R., Lebeau, O., Lluch-Cota, S. E., Salgado Garcia, R. L., Kainz, M. J., & Le Grand, F. (2019). Different particle sources in a bivalve species of a coastal lagoon: evidence from stable isotopes, fatty acids, and compound-specific stable isotopes. Marine Biology, 166(7), 89. https://archimer.ifremer.fr/doc/00501/61306/. https://doi.org/10.1007/s00227-019-3535-z Cite
Lelievre, Y., Sarrazin, J., Marticorena, J., Schaal, G., Day, T., Legendre, P., Hourdez, S., & Matabos, M. (2018). Biodiversity and trophic ecology of hydrothermal vent fauna associated with tubeworm assemblages on the Juan de Fuca Ridge. Biogeosciences, 15(9), 2629–2647. https://archimer.ifremer.fr/doc/00439/55083/. https://doi.org/10.5194/bg-15-2629-2018 Cite
Liénart, C., Savoye, N., Bozec, Y., Breton, E., Conan, P., David, V., Feunteun, E., Grangeré, K., Kerhervé, P., Lebreton, B., Lefebvre, S., L’Helguen, S., Mousseau, L., Raimbault, P., Richard, P., Riera, P., Sauriau, P.-G., Schaal, G., Aubert, F., … Sultan, E. (2017). Dynamics of particulate organic matter composition in coastal systems: A spatio-temporal study at multi-systems scale. Progress in Oceanography, 156, 221–239. https://archimer.ifremer.fr/doc/00374/48550/. https://doi.org/10.1016/j.pocean.2017.03.001 Cite
Gasmi, S., Bernard, I., Pouvreau, S., Maurer, D., Schaal, G., Ganthy, F., Cominassi, L., Allain, G., Sautour, B., & David, V. (2017). Spatial patterns in the condition index of the wild Pacific oyster Crassostrea gigas in a macrotidal coastal ecosystem: Influence of tidal processes and beyond. Journal of Sea Research, 119, 28–36. http://www.sciencedirect.com/science/article/pii/S1385110116300314. https://doi.org/10.1016/j.seares2016.10.008 Cite
Quillien, N., Nordstrom, M. C., Schaal, G., Bonsdorff, E., & Grall, J. (2016). Opportunistic basal resource simplifies food web structure and functioning of a highly dynamic marine environment. Journal of Experimental Marine Biology and Ecology, 477, 92–102. https://doi.org/10.1016/j.jembe.2016.01.010 Cite
Schaal, G., Nerot, C., Grall, J., Chouvelon, T., Lorrain, A., Mortillaro, J.-M., Savoye, N., Brind’Amour, A., Paulet, Y.-M., & Le Bris, H. (2016). Stable isotope ratios in bentho-demersal biota along a depth gradient in the Bay of Biscay: A multitrophic study. Estuarine Coastal and Shelf Science, 179, 201–206. fdi:010068095. https://doi.org/10.1016/j.ecss.2015.10.023 Cite
Schaal, G., Leclerc, J.-C., Droual, G., Leroux, C., & Riera, P. (2016). Biodiversity and trophic structure of invertebrate assemblages associated with understorey red algae in a Laminaria digitata bed. Marine Biology Research, 12(5), 513–523. https://doi.org/10.1080/17451000.2016.1164318 Cite
Le Croizier, G., Schaal, G., Gallon, R., Fall, M., Le Grand, F., Munaron, J.-M., Rouget, M.-L., Machu, E., Le Loc’h, F., Laë, R., & Tito-de-Morais, L. (2016). Trophic ecology influence on metal bioaccumulation in marine fish: Inference from stable isotope and fatty acid analyses. Science of the Total Environment, 573, 83–95. fdi:010068793. https://doi.org/http://dx.doi.org/10.1016/j.scitotenv.2016.08.035 Cite
Chouvelon, T., Schaal, G., Grall, J., Pernet, F., Perdriau, M., A-Pernet, E. J., & Le Bris, H. (2015). Isotope and fatty acid trends along continental shelf depth gradients: Inshore versus offshore hydrological influences on benthic trophic functioning. Progress in Oceanography, 138, 158–175. https://doi.org/10.1016/j.pocean.2015.07.013 Cite
Nerot, C., Meziane, T., Schaal, G., Grall, J., Lorrain, A., Paulet, Y.-M., & Kraffe, E. (2015). Spatial changes in fatty acids signatures of the great scallop Pecten maximus across the Bay of Biscay continental shelf. Continental Shelf Research, 109, 1–9. fdi:010065445. https://doi.org/10.1016/j.csr.2015.08.032 Cite
Schaal, G., & Grall, J. (2015). Microscale aspects in the diet of the limpet Patella vulgata L. Journal of the Marine Biological Association of the United Kingdom, 95(6), 1155–1162. https://doi.org/10.1017/S0025315415000429 Cite
Mortillaro, J. M., Schaal, G., Grall, J., Nerot, C., Brind’Amour, A., Marchais, V., Perdriau, M., & Le Bris, H. (2014). Comparative study of isotopic trends in two coastal ecosystems of North Biscay: A multitrophic spatial gradient approach. Estuarine, Coastal and Shelf Science, 136, 149–156. https://archimer.ifremer.fr/doc/00167/27847/. https://doi.org/10.1016/j.ecss.2013.11.025 Cite
Leclerc, J.-C., Riera, P., Leroux, C., Lévêque, L., Laurans, M., Schaal, G., & Davoult, D. (2013). Trophic significance of kelps in kelp communities in Brittany (France) inferred from isotopic comparisons. Marine Biology, 160(12), 3249–3258. http://link.springer.com/article/10.1007/s00227-013-2306-5 Cite
Marchais, V., Schaal, G., Grall, J., Lorrain, A., Nerot, C., Richard, P., & Chauvaud, L. (2013). Spatial variability of stable isotope ratios in oysters (Crassostrea gigas) and primary producers along an estuarine gradient (Bay of Brest, France). Estuaries and Coasts, 36(4), 808–819. http://link.springer.com/article/10.1007/s12237-012-9584-x Cite
Schaal, G., Riera, P., & Leroux, C. (2012). Food web structure within kelp holdfasts (Laminaria): a stable isotope study. Marine Ecology, 33(3), 370–376. http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0485.2011.00487.x/full Cite
Schaal, G., Riera, P., Leroux, C., & Grall, J. (2010). A seasonal stable isotope survey of the food web associated to a peri-urban rocky shore. Marine Biology, 157(2), 283–294. http://link.springer.com/article/10.1007/s00227-009-1316-9 Cite