Seminar of the AT ETE-Biodiversity on the theme : Stable isotopes, trophic guilds and fish assemblages: A functional approach of benthopelagic coupling in two contrasted marine environments"
On January 31st from 2pm in the Océanomed amphitheatre, you are invited to take part in the ETE-Biodiversity TA seminar led by our guest Pierre Cresson, researcher at the Laboratoire Ressources Halieutiques Manche Mer du Nord, Centre Ifremer Manche Mer du Nord, Boulogne sur Mer pierre.cresso@ifremer.fr
Abstract
The functional approach has emerged in recent years as a powerful tool for describing, understanding and predicting the response of biodiversity to environmental change (Mouillot et al. 2013). Among the existing set of functional traits, trophic traits are recognized as intuitive and effective enough to capture and synthesize interspecific interactions (Winemiller et al. 2015). This approach has thus greatly benefited from the widespread use of stable isotopes, and the recent development and calibration of numerical tools (Cucherousset & Villéger, 2015; Jabot et al. 2017).
Through two contrasting examples (Eastern Channel and Marseille Bay), the objective of this presentation will be to illustrate the relevance of the trophic functional approach to understand the importance of bentho-pelagic coupling on the structure of fish communities, in response to natural or anthropogenic variations, and also to show how this approach can provide elements for the management of natural systems.
In the Channel, the results highlight a strong influence of the benthic compartment on trophic structure, explaining in particular the preponderance of bentho-demersal species in the assemblage (Kopp et al. 2015; Giraldo et al. 2017; Cresson et al. in rev.).
In the Bay of Marseille, the functional approach shows that the implantation of artificial reefs did not modify the nature of the material flows, nor did it induce a different functioning from that of a fish assemblage associated with a "natural" hard substrate, but allowed an increase in flows, which is the origin of the increases in biomass observed for certain species (Cresson et al. 2019).