Monitoring of a Potential Harmful Algal Species in the Berre Lagoon by Automated In Situ Flow Cytometry

The vicinity of urban activity and industry (petrochemistry) around the Berre lagoon (southeast of France) has induced the degradation of its ecosystem, characterized by a permanent eutrophic state. In particular, a power plant has discharged substantial inputs of enriched freshwater in the lagoon since 1966. Due to these high nutrient inputs and also to regeneration rates, several species of phytoplankton regularly bloom in the lagoon at spring, summer, or autumn. Peaks of phytoplanktonic biomass (>150 μg Chla/dm3) are generally followed by intense heterotrophic activities leading to O2 consumption with hypoxic or anoxic episodes. The study of phytoplankton dynamics is thus of primary importance.