20 piezometers have been installed and monitored monthly since 2016.
A physico-chemical probe is installed on the marsh and measures water transparency, conductivity, dissolved oxygen, water pH, water height and silt depth.
A monitoring of amphibians, reptiles (laying 80 herpetological plates), fish and aquatic invertebrates was carried out. The Large Marsh Grasshopper population has been monitored since 2019.
The floral procession evolution is monitored in oligotrophic and peaty areas by applying a National Museum of Natural History methodology to record the communities evolution.
Bird counts have been carried out by the Hunting Federation of Ille-et-Vilaine Department for 30 years. Since 2016, they have been supplemented by a winter waterbird count, a monitoring of the reedbed passerines, ardeidae and anatidae reproduction. A mapping of the singing passerines is also carried out.
Design & implementations
However, the complete restoration of the hydrological functioning of the marsh has not been completed. The NWRMs therefore need to be complemented by water level management by means of a valve.
|Activity stage||Key issues||Name||Comments|
|Land use change type|
Lessons, risks, implications...
|Success factor type||Success factor role||Comments|
The low land pressure (and therefore low price) on these lands has facilitated acquisitions by the Hunting Federation of Ille-et-Vilaine Department. As they are not traditionally associated with nature protection in the eyes of the general public, the project was also an opportunity to bring about a change of perspective.
|Barrier type||Barrier role||Comments|
Attitude of relevant stakeholders
It has been difficult to make elected officials, the SAGE (water development and management scheme), as well as farmers who are still growing maize, understand the importance of restoring the wetland's functionality.
|Driver type||Driver role||Comments|
|Financing share type||Share||Comments|
Policy, general governance and design targets
It is the most massive peat deposit in the region.
The pressures on the site result from its development in the middle of the last century to facilitate agricultural activities:
Hydrological dysfunction causing the marsh to dry up in both winter and summer, and promoting peat mineralization.
Restore wet habitats, especially peat meadows;
Improve the marsh's carrying capacity for biodiversity, and in particular birdlife;
Improve the regulatory role of the marsh (carbon sequestration in peat, natural water purification);
Allow educational and recreational uses;
Enhance the value of the Hunting Federation of Ille-et-Vilaine Department action on the management of sensitive heritage habitats;
Collaborate with agricultural stakeholders.
|Pressure directive||Relevant pressure|
|Policy area type||Policy area focus||Name||Comments|
|Impact directive||Relevant impact|
|Wider plan type||Wider plan focus||Name||Comments|
Environment & Biodiversity
wetlands of the Bay of Mont-Saint-Michel
An increase in waterbirds halting;
An increase in breeding passerines;
An evolution of the common flora towards a more specific procession of peaty environment flora;
An increase in the geographical distribution of the Large Marsh Grasshopper.
The restoration of the reedbed has allowed the installation of the Marsh Warbler, which has only a few nests in Bretagne.