National observation network for the blue mussel Mytilus edulis

The national observation network for the blue mussel (MYTILOBS), set up in 2012, aims to monitor the growth and mortality of mussels produced for the market. The MYTILOBS is based on the experience of the regional network (REMOULA) which has been monitoring the growth of the blue mussel in the Charentais inlet since 2000. Monitoring mainly takes place the year following the year of capture: it thus integrates the main seasons of the biological life of the mussel, from winter maturation to spring growth, then to summer and fall fattening, the two periods when they are mainly sold. The choice of monitoring sites was decided in consultation between the Regional Environmental Resource Laboratories and the industry. For North Brittany, this is the site of Vivier-sur-Mer in (the sector of) the bay of Mont-Saint-Michel (mussel poles). Each breeding site is monitored every three months. Many parameters are measured including mussel size, weight and mortality. These data are examined taking into account environmental conditions such as temperature, salinity or the abundance and richness of the microalgae on which the shellfish feed. The Mytilobs national network is located in the main mussel-breeding regions of the Atlantic coast: Normandy, North Brittany, South Brittany, Pays de Loire and Poitou-Charentes. The sites of Agon (West Cotentin), Vivier (the bay of Mont Saint-Michel), Pont Mahe (Vilaine bay), Aiguillon (Breton inlet), Yves (Pertuis d’Antioche strait) representing, from north to south, mussel culture using poles. The Filiere site (Pertuis Breton - strait) represents mussels culture using ropes, in full water.