Coastal development has led to the destruction of intertidal and shallow subtidal habitats and loss of associated ecological functions. However, recent research programs have shown the capacity of a variety of man-made structures to host marine biodiversity. Coastal road embankments, harbor breakwaters or seawalls have for example proven to be attractive habitats for diverse marine species (algae, fish, crustacean, cephalopod) and of different life stages. In this way, these artificial habitats can contribute to the global quality of urbanized coastal ecosystems. This being said, the magnitude of this contribution and the habitat efficiency of these infrastructures highly depends on a certain number of factors, both environmental (eg. hydrodynamics and water quality) and technical (eg. infrastructure size, macro and microstructure, material). Today, coastal transport infrastructures are not specifically designed to supply key environmental functionalities, and their ecological potential is generally limited. Ecological enhancement (or habitat enhancement) through ecological engineering is a growing discipline aimed at increasing habitat quality of immersed man-made structures in order to reduce global impact of infrastructure development on aquatic ecosystems.
This presentation will focus on a few case studies of recent projects for which habitat enhancement was applied to maritime transport infrastructure:
- The Réunion island coastal road
- The extension of the industrial ports of Brest and Marseilles
The presentation will conclude on the potential of habitat enhancement of man-built inland waterways and how it could serve a better control of species dispersal and connectivity between distant watersheds.