Figure 3 and 4 show the distribution of surface temperature observed by thermograph at 4 m of depth. When analyzed together with the hydrographic profiles evidence of gradients of declining temperature shorewards demonstrate areas of upwelling. Figure 5 shows the distribution of temperature, salinity and oxygen in the profiles of the western part (Oriente). Off the Paria Peninsula the temperatures on the innermost station are 4-6°C lower than those off the shelf at the same depths and seen together with the isolines for salinity and oxygen the profile gives a picture of clear upwelling with intermediate water from 75 - 100 m being lifted over the shelf and transported shorewards and to the surface inshore. In the Cariaco Trench profile there is hardly any gradient shorewards in the surface temperature. The isolines for salinity and oxygen lifts northwards and there is an indication of a treshold at about 200 m. Light eastward current was at times observed over the inner shelf. The well known oxygen deficiency in the Trench was duly observed, with zero oxygen from 400 m down.
The hydrographical section northwestwards from Cabo San Roman and the section into the Gulf of Venezuela (Fig. 6a, b) portraits water masses with a slight upwelling in the mouth of the Gulf, but the intensity of the process is considerably less than off the Oriente coast. The upwelling, which does not reach all the way to the surface is also confirmed in the hydrographical section off Peninsula de la Guajira, Fig. 6 c. The salinity drops slightly in the inner part of the Gulf due to freshwater runoff.
