Excrétion organique du phytoplancton et activité bacterienne hétérotrophe dans le Dôme de Guinée (Océan Atlantique Tropical Est)

Primary production rates in the Gulf the Guinea (east tropical Atlantic) were measured with in situ incubations. The extracellular organic carbon passed through 0.8 u pore size membrane filters averaged 29.5% of the carbon fixed by photosynthesis. These is a good linear correlation (r=0.86) between assimilation and organic excretion. The significance and limits of the method for the measurements of low rates of photosynthesis is discussed. The influence of ecological factors (nutrients, light and stability) cannot be demonstrated. The importance of bacterial regeneration processes by reutilization of algal extracellular products is assessed.

Activité de la station séismologique de Nhatrang durant la période Juin 1957-Décembre 1963

In June 1957, the Oceanographic Institute of Nhatrang agreed to support a seismological station whose equipment (3 CP components) was loaned by the National Centre for Scientific Research of France. Similarly, in order to develop its research activities, the Institute cooperated with the United States in their project for seismographs standardization. The author gives a detailed description of the new equipment (3 components and 3 C.P. L.P. components) received from U.S. and installed in June 1962.