Mussel samples have been placed in plastic-mesh bags hung on wood poles (« bouchots »), at 4 locations of a mussel culture area in the bay of Vilaine (South Brittany, France). They have been monitored for one year, from February 2000 to February 2001. The recorded growth have been rather fast (plus 1.2 g per month between April and September), and mortalities moderate (between 15% to 25%), with better results in southern stations, further from the estuary. Among the physico-chemical parameters recorded, the most striking were very low salinities (below 10 g/l) recorded for days, after heavy rains. They provoqued a valve closure of mussels (recorded by a « valvometer »). Some physiological indicators being tested (muscle force and hermeticity) seemed to... |