The hydrographical sections off the Peninsula of Guajira, off Riohacha and off the Rosario Island are shown in Figure 2a and b. The section in the Gulf of Venezuela worked during previous survey, Part 3, is included in the Figure 2a. There are indications of weak upwelling in the profiles off Peninsula de la Guajira and Riohacha but not in the profile off Islas del Rosario. The hydrographical situation in the Rosario section is comparable to the conditions in previous surveys with influence of river discharge in the surface layers. Sligthly lower salinity in the surface layers in the section off the Peninsula profile indicates influence from the Gulf of Venezuela.
