TEMPERATURE AND SALINITY TRENDS IN GUANABARA BAY (BRAZIL) FROM 1980 TO 1990

Temperature and salinity in Guanabara Bay were studied during the last eleven years and the quantification of changes in water characteristi cs is presented. The mean temperature was 25.2-degrees-C (surface) and 23.7-degrees-C (bottom) and no trends were discernible. As a whole, t he Bay showed a decrease in salinity in both surface and bottom (-0.14 5 S year-1, or -4.9%). Salinity has decreased in bottom waters and mor e rapidly in areas under greater anthropogenic influence (western regi on, -0.60 S year-1 or -21.0%). The rates of salinity decrease were hig her than those expected. We attribute the decrease to increased runoff , high sedimentation rates, and landfills and consequent modifications of the circulation patterns.