Figure 2 shows the surface temperature over the shelf, while Figure 3 a, b, shows the two sections worked off Nicaragua. Off San Juan del Sur there is a decrease of the surface temperature towards the shore which is more pronounced than in May and resembles the situation found during Survey I in February. This finding suggests that local upwelling takes place here over a considerable part of the year brought about by the prevailing north- and northeasterly winds. The distribution of temperature, salinity and oxygen in the section off San Juan del Sur confirms the existence of a process of upwelling of intermediate water in this area. Over the remaining part of the Nicaraguan shelf the sea surface temperature increases towards the shore. The hydro-graphic section off Golfo de Fonseca shows that the surface temperature is higher and the salinity lower inside the Gulf itself than found in previous surveys. Otherwise there are no changes from the situation observed during the previous surveys. No changes can be observed in the environment of the offshore community at depths from 100 - 300m. The temperature ranges from 11-12°C to abt. 17°C and the oxygen content remains below 1 ml/l.
The sea surface temperature off El Salvador (Figure 2) shows an increasing trend towards the shore with temperatures reaching 30°C over most nearshore parts. The hydrographic section off Acajutla (Figure 3) shows the transition layer from 30 to 75m inshore and from 50 to 100m in the oceanic part. The surface salinities may be affected by the rainy season.
