Context:
The growth of global trade has resulted in the displacement and introduction of a large number of species around the world (Seebens et al., 2017). These species, if they become establish in their new environment, can have important impacts on the native ecosystems. Freshwater fish species are known to be one of the most introduced taxa around the world, and to cause important ecological and socio-economic impacts (Cucherousset and Olden, 2011; Haubrock et al., 2022). The invasion success of freshwater fishes is influenced by several factors, including the ecological characteristics of the receiving ecosystems (Pyšek et al., 2020). Thus, aquatic ecosystems which are heavily or frequently disturbed by humans, seem to be highly susceptible to invasions (Leprieur et al., 2008; Clavero et al., 2013).
One of the particularities of freshwater fishes is that they evolve in drainage basins, which are closed ecosystems of interconnected rivers, which can be assimilated to islands regarding their isolation and endemism for example (Tedesco et al., 2012). Invasion process on islands is well-known in the literature for terrestrial taxa (Blackburn et al., 2008; Walsh et al., 2012; Dawson et al., 2017). It has already been demonstrated that invasibility of site depends of ecological processes such as ecological interactions, and of human processes. Indeed, Blackburn et al. (2008) demonstrated that the island area, the island isolation and the human activities are significantly correlated with the number of established non-native birds. Walsh et al. (2012) demonstrated that a high ecological impact of exotic bird, amphibian and mammals on islands is linked with a high colonization pressure (i.e. a high number of exotic species), and a high species endemism. Their results also suggest an influence of the habitat heterogeneity and of the species richness on the island. Here, we seek to test the hypothesis that variables known to influence invasions patterns in islands are similar to those influencing invasions in drainage basins because of their island-like isolated nature. We propose to explore this question by analyzing the relative influence of variables on exotic species richness per drainage basins, with statistical approaches. We used existing studies on the biogeographical variables found to influence invasions on islands to make an a priori selection of 5 variables that may have an influence on the non-native species number in basins.

Data :
• Response variable:
Number of established species obtained in (Tedesco et al., 2017).

• Explanatory variable (which are expected to increase the number of exotic species in basins; Blackburn et al., 2008; Walsh et al., 2012):
– Drainage basin area. Obtained in the Tedesco et al., 2017 database
– Native fish species richness. Obtained in the Tedesco et al., 2017 database.
– Human population size or human perturbation. Obtained through the WorldPop (https://map.unbiodiversitylab.org) and the GOODD (Global Georeferenced Database Of Dams – (https://map.unbiodiversitylab.org)) databases.
– Isolation. Obtained thanks to the « Travel time to major city  » database (https://forobs.jrc.ec.europa.eu/products/gam/download.php; Nelson, 2008)
– Habitat heterogeneity. Obtained thanks to the Worldclim database (https://www.worldclim.org/).

Méthodes mises en œuvre : Recherches bibliographiques en anglais (Google scholar, World Of Science…), construction de la base de données, analyses statistiques sous R (régression linéaire, GLMs…), manipulation de cartes sous R (e.g. manipulation de shapefiles).

Logiciels utilisés : Zotero / Mendeley, RStudio.

Profil recherché : Stage ouvert à des étudiant en M2 ou en césure. Bonne maîtrise du fonctionnement de base de Rstudio. Intérêt pour l’analyse de données.

Date limite de candidature : 15 Janvier (CV + lettre de motivation).

Lieu : Ce stage se déroulera au sein de l’équipe BioM du laboratoire ESE à Orsay (91400) (https://www.biodiversitydynamics.fr/ ; https://www.ese.universite-paris-saclay.fr/dynamiaque-de-la-biodiversite-et-macro-ecologie/). BioM est une équipe dynamique qui a vu le jour il y a deux ans. L’équipe organise beaucoup d’évènements sociaux et est en général très présente pour ses stagiaires. L’équipe accueillera aussi 5 autres étudiants de master, le but étant qu’il y ait une dynamique d’entraide et de partage entre les étudiants. Il est prévu que le labo déménage en Avril dans de tout nouveaux bâtiments sur le plateau de Saclay.

Date de début et durée du stage : L’idéal serait de pouvoir débuter le stage mi-février, et de le terminer en Juillet. Cependant, les dates sont flexibles suivant les disponibilités du stagiaire.

Gratifications : Gratifications réglèmentaires (environ 590 € par mois).

Supervision: Camille Bernery & Céline Bellard.

Contact:
• Camille Bernery, Doctorante, Lab. ESE, BioM team: camille.bernery@universite-paris-saclay.fr,
• Céline Bellard, Chargée de recherche CNRS, Lab. ESE, BioM team : celine.bellard@universite-paris-saclay.fr,
• Boris Leroy, Maître de conférence, Lab BOREA (MNHN) : leroy.boris@gmail.com,
• Franck Courchamp, Directeur de recherche CNRS, Lab. ESE, BioM team : franck.courchamp@universite-paris-saclay.fr

References :
Blackburn, T.M., Cassey, P. and Lockwood, Julie.L. 2008. The island biogeography of exotic bird species. Glob. Ecol. Biogeogr., 17: 246–251.
Clavero, M., Hermoso, V., Aparicio, E. and Godinho, F.N. 2013. Biodiversity in heavily modified waterbodies: native and introduced fish in Iberian reservoirs. Freshw. Biol., 58: 1190–1201.
Cucherousset, J. and Olden, J.D. 2011. Ecological Impacts of Nonnative Freshwater Fishes. Fisheries, 36: 215–230.
Dawson, W., Moser, D., van Kleunen, M., Kreft, H., Pergl, J., Pyšek, P., et al. 2017. Global hotspots and correlates of alien species richness across taxonomic groups. Nat. Ecol. Evol., 1: 1–7.
Haubrock, P.J., Bernery, C., Cuthbert, R.N., Liu, C., Kourantidou, M., Leroy, B., et al. 2022. Knowledge gaps in economic costs of invasive alien fish worldwide. Sci. Total Environ., 803: 149875.
Leprieur, F., Beauchard, O., Blanchet, S., Oberdorff, T. and Brosse, S. 2008. Fish Invasions in the World’s River Systems: When Natural Processes Are Blurred by Human Activities. PLoS Biol., 6: e28.
Nelson, A. (2008) Travel time to major cities: A global map of Accessibility. Office for Official Publications of the European Communities, Luxembourg. DOI:10.2788/95835, ISBN:978-92-79-09771-3.
Pyšek, P., Bacher, S., Kühn, I., Novoa, A., Catford, J.A., Hulme, P.E., et al. 2020. MAcroecological Framework for Invasive Aliens (MAFIA): disentangling large-scale context dependence in biological invasions. NeoBiota, 62: 407–461. Pensoft Publishers.
Seebens, H., Blackburn, T.M., Dyer, E.E., Genovesi, P., Hulme, P.E., Jeschke, J.M., et al. 2017. No saturation in the accumulation of alien species worldwide. Nat. Commun., 8: 14435.
Tedesco, P.A., Beauchard, O., Bigorne, R., Blanchet, S., Buisson, L., Conti, L., et al. 2017. A global database on freshwater fish species occurrence in drainage basins. Sci. Data, 4: 170141.
Tedesco, P.A., Leprieur, F., Hugueny, B., Brosse, S., Dürr, H.H., Beauchard, O., et al. 2012. Patterns and processes of global riverine fish endemism. Glob. Ecol. Biogeogr., 21: 977–987.
Walsh, J.C., Venter, O., Watson, J.E.M., Fuller, R.A., Blackburn, T.M. and Possingham, H.P. 2012. Exotic species richness and native species endemism increase the impact of exotic species on islands. Glob. Ecol. Biogeogr., 21: 841–850.

Le contenu de cette offre est la responsabilité de ses auteurs. Pour toute question relative à cette offre en particulier (date, lieu, mode de candidature, etc.), merci de les contacter directement. Un email de contact est disponible: camille.bernery@universite-paris-saclay.fr

Pout toute autre question, vous pouvez contacter sfecodiff@sfecologie.org.