Panama
Figure 3 shows the surface temperature over the shelf. In the Gulfs of Panama and Coiba the temperature increases from abt. 24° C in the north to abt. 27° C over the edge of the shelf. This is likely to be an effect of the prevailing northerly winds. For the Gulf of Panama the surface temperatures shown in Figure 3 refers to the period 4-9 February. The hydrographic profile in the Gulf, see Figure 4 was carried out 10-11 February during a spell of strong northerly wind, force 7-8. It is seen that the surface temperature had by then dropped abt. 1° C in the north and abt. 3° C in the southern part of the Gulf. The profile further shows that there is a transition layer between abt. 30 and 50 m of depth where water temperature, salinity and oxygen content changes markedly. The form of the isolines for temperature and oxygen indicate that upwelling takes place and that water of low temperature and low oxygen content is brought into the deeper parts of the Gulf. The profile from the Gulf of Quiriqui' is different, with the transition layer deeper, between 50 and 75 m and no signs of upwelling.
Costa Rica
Figure 5 shows the surface temperature distribution. In the south there is a slight decline from the shore seawards and lower temperatures northwards. Figure 6 shows the conditions in Golfo Dulce based on two stations there, and the section from Golfo Nicoya seawards. Golfo Dulce has a treshold of about 45 m at the entrance and this affects as one can see the hydrographic conditions drastically. Of special importance is the oxygen deficiency deeper than about 50 m. In the Golfo de Nicoya section the transition layer is found approximately in the 50 - 75 m range. The 2 ml/l oxygen limit is found at about 75 m depth in the Gulf.
