Comparison of some physicochemical aspects and hygienic qualities of the Puntarenas Estuary, Costa Rica

Nutrients, temperature, Secchi disk depth and dissolved oxygen spatial dist ributions were determined along the Puntarenas Estuary. Eleven sampling cru ises took place in 1982 and twelve more were carried out during 1990-1992, collecting water samples on a surface and bottom basis along the salinity g radient at six and nine stations, respectively. Salinity profiles indicated a partially mixed estuary during most of the cruises, although the strong tidal current ocasionally modified the pattern. During the second part of t he study, the global concentration ranges for nitrate and phosphate were br oader than those in the first part. Total and fecal coliforms (TC, FC) were determined as most probable number (MPN/100 mi) during six cruises of the second period in nine stations; results showed a typical situation of a ver y polluted estuary, with values in the range of less than 2 to 1.6 x 10(7) MPN/100 Int for TC and less than 2 to 9.2 x 10(6) MPN/100 mi for FC.