SPATIAL AND TEMPORAL VARIABILITY OF SAPHROPHYTIC BACTERIA IN THE SURFACE WATERS OF PARANAGUA AND ANTONINA BAYS, PARANA, BRAZIL

Spatial and temporal variability in the concentration of saprophytic bacteria was investigated in surface waters of Paranagua and Antonina bays. Seven points along a profile from the entrance of Paranagua Bay to the innermost part of Antonina Bay, were sampled monthly from November 1985 to November 1986. Temperature, dissolved oxygen, pH and precipitation data were also measured. ZoBell 2216E culture medium was utilized with freshwater and 32% salinity water. Principal component analysis of biotic and abiotic data showed a gradient from the innermost bay to the baymouth bar with an increase in bacteria concentration at Antonina Bay. Significant variation was not observed among sampling stations at Paranagua Bay, except for February 1986 when there was a homogeneous increase of bacteria throughout both bays in association with an increase in temperature and precipitation. There was also no strong variation of saprophyte numbers at sampling locations near Paranagua city, despite domestic and harbour waste input. We conclude that the outer region of the estuary is highly influenced by the adjacent ocean and that the inner part has typical estuarine characteristics. The region may be considered little polluted.