| More and more studies emphasize the status of phosphorus (P) as the principal limiting nutrient of phytoplankton growth, especially in coastal waters under the influence of freshwater discharges. The purpose of the present paper is to investigate the role of P on planktonic production in the waters influenced by the Gironde discharges; the Gironde being one of the two largest rivers on the French Atlantic coast. The survey is based on several cruises made in 1998 and 1999. Two different patterns were observed for waters with salinity below and above 34.5. For waters with salinity <34.5. P was found to be the first limiting nutrient of winter and spring phytoplankton blooms, based on undetectable phosphate (<20 nM), high NO3 : PO4 ratios, typically... |
