Water and sediment samples were collected from four sites extending for about 20 Km from the
beginning of Ismailia canal. The samples were collected seasonally for the chemical screening of hydrocarbon
pollutants via capillary gas chromatography and collected monthly for the bacterial assessment during the
period from August 2007 to July 2008. The results demonstrated that all sites contain a mixed source of biogenic
and petrogenic hydrocarbons but the biogenic hydrocarbons were stronger than the petrogenic hydrocarbons
in the beginning of the canal while in the other three sites especially at petroleum companies, the pollution
source was largely of petroleum-derived materials. The average count of total heterotrophic bacteria in water
samples was 104 CFU/ml, while in sediment samples was 105 CFU/ml. The average density of crude oil utilizing
bacteria in water samples was 103-104 MPN/100ml, while in sediment samples was 105 MPN/100ml. The average
of hydrocarbon degrading bacteria within the average of heterotrophic communities was fluctuated between
0.2% to 2.1%. The highest average percent of degrading bacteria in water and sediment samples was found at
petroleum companies. So the percentage of hydrocarbon degrading bacteria was taken as a sensitive index of
environmental exposure to hydrocarbon pollutants.