Abstract
The relationships between indicator bacteria and the organic load were conducted over a year in Lake Pamvotis, in northwest Greece. Total coliforms (TC) and fecal coliforms (FC) were found in water samples from five different sampling stations. Organic load was estimated using biological oxygen demand (BOD) and chemical oxygen demand (COD) parameters. Increased TC and FC levels were found close to heavily polluted areas. Near-bottom samples had higher levels of bacteria and the numbers of TC and FC were increased during rainfall periods. Low or negative correlations were also observed between the bacteriological indices and BOD and COD levels, thus strengthening the hypothesis that indicator bacteria mainly depend upon the origin of pollution rather than the amount of the organic load. It is conceivable that systematic bacteriological and chemical indices must be monitored in order to evaluate the ecosystem and to protect public health.