How to study the social-ecological impacts of invasive species: the case of the ctenophore Mnemiopsis Leidyi in Berre Lagoon (Southeast France).
Berre Lagoon is an ecosystem historically disturbed by strong industrial discharges and significant freshwaters inputs from both natural and anthropogenic (hydroelectric powerplant) sources. While rehabilitation policies initiated in 1994 are already showing some success, the introduction and proliferation of Mnemiopsis leidyi since 2005 could limit their effectiveness. The originality of this study is to associate oceanography and sociology to estimate the impact of M. leidyi on the functioning of this socio-ecosystem. This article presents an overview of a broad range of results obtained using interdisciplinary approach. It appeared that M. leidyi has an impact on plankton community functioning and on human activities, particularly on fishing. Therefore, in the context of biological invasions, the prospects for the rehabilitation of Berre Lagoon remain subject to the unpredictability of nature.