Context
The Iroise Sea is home to one of the largest seaweed beds in Europe, with more than 300 different species of algae. Among these, the laminarians, large brown algae that are distributed in layers within the rocky areas that are favorable, can form veritable underwater forests.
Although the Iroise Sea remains fairly stable today thanks to the physical impact of the Ouessant thermal front; it is important, in this context of increasing pressure linked to anthropogenic activities (temperature, acidification, exploitation, pollution, etc.), to equip oneself with relevant and necessary monitoring means to follow and understand the evolutionary trajectory (regression, stabilization, expansion).
It is in this context that this project is being carried out. The objective of this study is to lay the foundations for what will one day become a network for observing and monitoring this heritage habitat within the Marine Park of the Iroise Sea.
DETAILED MISSIONS
The PNMI It entrusted setec énergie environnement with the task of identifying sites in order to obtain information to select a portion of them that can be integrated into a future monitoring network within the park’s perimeter.
The objective of this study was to identify sites that could be subject to monitoring as part of an observatory for the laminarians in the Iroise Sea. These sites were intended to provide a representative view of the macroalgae fields, particularly the mole plate. They were also intended to measure the natural evolution of the laminarian populations and to integrate the effects of their exploitation.
These sites have allowed for monitoring over a depth gradient of at least –13 m CM if possible, in order to enable, in the future, the application of the «DCE2‑complete» protocol to part of the selected sites.
- Data acquisition from 30 diving sites;
- Banking and data analysis;
- Compared with the data available through surveillance networks (DCE, REBENT);
- Proposal of sites to be preserved for the establishment of an observatory.
