SENSITIVITY TO STRESS OF THE ESTUARINE BIVALVE MACOMA-BALTHICA FROM AREAS BETWEEN THE NETHERLANDS AND ITS SOUTHERN LIMITS (GIRONDE)

Variation in the sensitivity to stress of Macoma balthica was measured in several French and Dutch estuaries. For adult and juvenile Macoma balthica exposed to copper under conditions of starvation, differences in mortality rate, condition, glycogen, burrowing rate and copper con tent were assessed. No significant differences were observed between a dults and juveniles; the influence of treatment and origin was always evident. Animals from the most southern estuaries, Loire and Gironde, near to the species's southern limit of distribution, showed, in the f ield, the strongest deviations for the ecophysiological traits measure d, and were in the experiments the most sensitive to stress.