Coastal grey artificial structures can greatly modify communities and ecosystem functioning, often decreasing biodiversity and enhancing biological invasions. The artificialisation of these habitats does not allow real measures of restoration. However, it is possible to ameliorate biodiversity and functioning and reconcile these systems with nature. The private company Ecocean (https://www.ecocean.fr/home/) has designed artificial nurseries called Biohut in order to facilitate the recruitment of fishes in ports.

The aim of this thesis is to improve the understanding of trophic relationships within these nurseries and with the surroundings and make hypotheses about the role of Biohut in influencing trophic connectivity of these areas. We will use bulk stable isotopes (SI) in order to establish trophic connections and define the trophic role of these Biohut. We will also sample for species and functional diversity in order to improve knowledge about the role of Biohut in imporving port reconciliation.

This PhD thesis is funded by the ANRT (association national recherche technologie) with the CIFRE program.