Spatial and temporal variability of saprophytic bacteria in water's column on the Paranagua Bay, Parana, Brazil.

Spatial and temporal variation in the concentration of saprophytic bacteria were assessed at two fixed points (Maciel Station and Pecas Station) in a vertical column at Paranagua Bay. Comparison among salinity, dissolved oxygen, seston, water transparency and precipitation were effected. Monthly samples were collected each 2 m in a vertical column from surface down to the sea bottom from May 1987 to June 1988 in Maciel Station and from June 1987 to June 1988 at Pecas Station. ZoBell culture medium was used in two different concentrations - freshwater and 32 parts per thousand salinity. Principal component analysis of biotic and abiotic data showed that there was not a vertical gradient in the saprophytic bacteria number in the period and area studied. Water transparency and bacteria had a positive correlation at Maciel Station while at Pecas bacteria was positively correlated with seston. These results suggest that at Maciel free living bacteria dominates while at Pecas saprophytic bacteria lives attached to particles. Eventhoug the two sampling places are strongly influenced by the adjacent sea they differ as to the bacterial habits.