Spatial Variation of Bacteria in Surface Waters of Paranaguá and Antonina Bays, Paraná, Brazil

Abstract

Spatial variability in the concentration of total bacteria, saprophytes and coliforms abundance was investigated in surface waters of Paranaguá and Antonina Bays. Six points along a profile from the entrance of Paranaguá Bay to the innermost part of Antonina Bay, were sampled on February 26, 1997. Temperature, salinity, dissolved oxygen, pH, particulate organic carbon, water transparency and seston were also measured. Determination of total bacterial abundance and biomass were made with the epifluorescent method. Saprophytic bacteria counts were conducted with ZoBell 2216E culture medium with fresh and 32‰ water and the coliform MPN was enumerated with the chromogenic substrate method. Principal component analysis of biotic and abiotic data showed a gradient from the innermost bay to the baymouth bar with an increase in total and halophobic aerobic cultivated bacteria concentration at Antonina Bay. Greatest values of halophilic aerobic cultivated bacteria were found at the bay’s middle part. The greatest fecal coliform number was observed near Paranaguá City. We concluded that regarding bacterial spatial distribution the outer region of the estuary was highly influenced by the adjacent ocean and that the inner part had typical estuarine characteristics.