What kind of actions for the Lake of Duc?

Since the end of the 1980s, the development of cyanobacteria in Lac au Duc water has become a problem, which is increasing every year in order to achieve longer bathing and consumption bans. . Since the 90s, several temporary actions have been put in place to fight against these cyanobacteria but without definitive results. In response to these concerns, on June 4, 2018, the Community Council approved Ploërmel Community's participation in the international InterregCPES project (see Context of the Action) to provide a thorough understanding of the Lake's functioning.

Context of the action

Lac au Duc and the Yvel-Hyvet catchment area of ​​6 pilot sites of the Interreg IV France (Channel) England cooperation Channel Payments for Ecosystem Services (CPES). On this case study, the scientific partners (CNRS, INRA, University of Rennes 1, Sara Hernandez Consulting, West Agrocampus, CRESEB) and local (Great Basin of the Oust, Ploërmel Community, Pays de Ploërmel) seek to restore the quality of the water and the environment, studying the fluxes of phosphorus in the watershed, the financial modalities of accompaniment to the changes of practices of the farmers to know the dynamics of development of the cyanobacteria in the Lake and to experiment new actions curative in Lake swimming area. For Lac au Duc and the Yvel-Hyvet catchment area, the project partners are investing more than 1.5 million euros for the territory.

Goals

  •  Inform about the fragility of Lac au Duc and the rivers, the water resource and the reconquest of the aquatic environment.
  •  Highlight the complexity and richness of phytoplankton biological life as well as the variability of developments and the difficulty of anticipating plankton blooms of cyanobacteria.
  •  To bring out the societal demand.

Useful information

    Date: Friday, June 7, 2019 from 8pm
    Venue: Room A, Festival Hall Ploërmel

Program

  •     8:00 pm: Introduction

  • 20h15: Introduction of phytoplankton and cyanobacteria - University of Rennes 1

    • Public Health Risk Management-ARS 56

    • Impact on economic structures-Fishing, Nautical Club, AEP

    • Remediation actions - University of Rennes 1

  •     9:30 pm: Questions / Answers

  •     22:00: Friendly pot