Copper tolerance in Haslea ostrearia assessed by measurements of in vivo esterase activity

In vivo measurements of Haslea ostrearia esterase activity allowed to assess the effect of copper on metabolic activity. This method, when applied to the micro-plate reader, is effective to screen different cell stages and physiological conditions. Results showed that copper toxicity varies according to the physiological stage of the microalgae and especially in relation with the presence of a blue-green pigment synthesised by the diatom. This compound, responsible for the blue-green colour of oyster gills, may play an important role in copper bio-availability in oyster ponds.