The following parameters were measured: pH, dissolved oxygen (DO), temperature, concentrations of chlorophyll (a and b), concentrations of ammonium (NH4+), nitrite (NO ), nitrate (NO3) and phosphate (PO43 ), particulate nitrogen (N ) content of the biomass, total suspended solids (TSS) and volatile suspended solids (VSS). The pH measurements were carried out twice a day. Data on pH represent the highest value of the two measurements of the day day (à supprimer).