Non‐native species modify the isotopic structure of freshwater fish communities across the globe

Early View (EV): 1-EV modify community composition and the network of trophic interactions (through the extinction or extirpation of native species and the addition of new non-native species, Cucherousset et al. 2012b).Freshwater ecosystems are considered among the most altered in the world, especially because of the widespread introduction of non-native fi shes (Copp et al . 2005). Introduced fi sh species have been demonstrated to alter existing biological interactions among native species (Vander-Zanden et al. 1999, Cucherousset and Olden 2011). In many instances introduced fi sh species have a larger body size than native species (Blanchet et al. 2010) and large-bodied introduced predators could increase food chain length whereas largebodied introduced herbivores could modify the basal structure of food webs modifying the overall trophic structure of recipient communities (Cucherousset et al. 2012a). To date, however, most of the studies investigating the impacts of non-native species on the trophic structure of communities were conducted locally and there is to date no global understanding. Th is is despite the fact that such