Composition en éléments azotés minéraux et organiques dissous de l'eau du bassin conchylicole de Marennes-Oléron

Values of nitrogen nutrients (ammonia, nitrite and nitrate) are compared with values of total organic nitrogen and urea. In summer, the consumation by micro and macrophytes is added to less important telluric input of nineral nitroge. However, an important provision of organic nitrogen remains. On the contrary, in winter, organic nitrogen does not represent more than 10% of total nitrogen. The autors postulate that populations of oysters are at the starting point of the organic nitrogen production cycle.