Microbiology of a northern river: bacterial distribution and relationship to suspended sediment and organic carbon

Abstract

Epifluorescent microscopy showed as many as 4 x l06 bacteria/minL t he turbid waters of the Athabasca River near the tar sand deposits in northeastern Alberta. The numbers were usually similar upstream and downstream (60 km) from pilot-mining operations. The majority of bacteria existed as free-living cells in spite of the fact there were high concentrations of suspended sediment present (average 220 mg/L) dul-ing the ice-free period. Fluctuations in bacterial concentration were positively correlated (r= 0.86, P< 0.05) with total organic carbon concentrntions in the river water.