[Spatial and temporal distribution of aerobic bacteria in the Bahía Blanca estuary, Argentina]

In order to study the baseline of the present bacteriological state in Bahia Blanca estuary (4) (Fig. 1 ), 13 sampling-stations were established Water samples were drawn from subsuperficial and 3 m depth from June 1984 to October 1985, during ten cruises. The heterotrophic aerobic, marine (BM) and terrestrial (BT) bacteria counts were subjected to analysis of variance (ANOVA), which were highly significant for both sampling stations and months of the year (Table 1). Scheffe's and Student-Newman-Keul's contrast tests were used to indicate which sampling stations and months of the year resulted in significant differences in number of bacteria (Tables 2, 3). Subsuperficial and 3 m counts were analysed by the signification F test. No significant differences were detected. Very good correlations were observed between BM and BT at each level (Table 4). Bacteria behaviour characteristics would be used to detect changes produced in the estuary due to human activities.