Ploërmel - 7th of June 2019 - Filled hall for the evening of information and exchange

On Friday, June 7th of 2019, in the village of Ploërmel, we had more than 115 people attending  an evening of information and exchange on the ecological status of Lac au Duc and curative actions that can be put in place to improve the water quality of the lake, organized as part of the Green Week.

A great success

Research engineers, elected officials, the fishing association, and local economic actors attended this evening, where reporters from the Ploermelais newspaper were also present. The state of Lac au Duc is a concern. It was together that the actors exchanged discussion for nearly three hours on the sources of the problem, the local impact and what could be put in place in other lakes around the world.

Gérard Payot (referent of the water commission of the association Polen), Patrick Le Diffon (mayor of Ploërmel) and Patrick Latouche (director of the SMGBO) introduced this evening by specifying the state of the Lac au Duc and the experiments carried out to treat the lake.

  • Morgane Le Moal (research engineer at the University of Rennes 1) enlightened the public on a theme that may seem a bit complex: what are phytoplankton and cyanobacteria? She returned to the ecological status of Lac au Duc and its dynamics since the early 2000s.

  • Pascal Chemin (the Ablette Ploërmelaise AAPPMA) presented economic issues related to the quality of the lake seen from the fishermen's side.

  • Gérard Payot presented the management of drinking water and risks to public health (especially bathing).

  • Claudia Wiegand (researcher at the University of Rennes 1), scientific partner of the Interreg CPES project, intervened by presenting curative actions illustrated with concrete examples of successful international projects.


Citizens, farmers and elected officials spoke in turns during the evening's debate, questioning both the concrete short-term solutions, the central role of farmers and the concrete implementation of the CPES project... This lively and powerful debate has created questions and awoken consciences; many people left with even more questions and the desire to find solutions to improve together the ecological quality of the lake.