SPATIAL-DISTRIBUTION AND TEMPORAL VARIABILITY OF HETEROTROPHIC BACTERIA IN THE SEDIMENTS OF PARANAGUA AND ANTONINA BAYS, PARANA, BRAZIL

The temporal and spatial variability of heterotrophic bacteria was ana lyzed in sandy, sandy-silt and silty sediments of Paranagua and Antoni na Bays (SE Brazil). Samples were taken from seven stations along a sa linity gradient, from the Paranagua Bay access to Corisco Island in An tonina Bay, between November 1985 and November 1986. The results were compared with deep-water salinity, pH, temperature, dissolved oxygen a nd rainfall. ZoBell 2216E, at the salinities 0 parts per thousand and 32 parts per thousand, was used as culture media. Principal component analysis showed that the concentration of heterotrophic bacteria was c onsistently lower in sandy sediments near the entrance of the Paranagu a Bay. Otherwise, the silty sediments did not differ significantly fro m the other sediments. Highest halophilic levels were recorded at the mouth of Maciel tidal creek. These results suggest that the amount of bacteria, in the region, is not related to sediment grain size but to currents speed which may benefit or not the organic matter deposition. Non halophile and halotolerant bacteria can be limited by high salini ty. Contrary to observations in the water column, high pluviosity did not influence the heterotrophic bacteria number in the sediment from t he studied area.