Abstract:
A survey on the oil content and diatom abundance has been conducted in the coastal water around oil
industry activities. Two locations (Sungai Pakning and Selat Lalang) with three s tations each were
selected for the sampling. Oil content analysis and identification of diatom were carried out in Marine
Chemistry Laboratory and Marine Biology Laboratory , Faculty of Fisheries and Marine Science,
University of Riau. The results showed that all water quality parameters measured in the present study
were still in the range of tolerable levels for the survival of marine organisms. The mean oil content
varies from 0.35 to 0.37ppm and diatom abundance ranged from 1433.33 – 1566.67cel/L consisted of 10
species in Sungai Pakning whilst oil content in Selat Lalang ranged from 0.34 to 0.54 ppm and diatom
abundance 1813.33 – 2200.00 cel/L with 7 spesies. Oil contents found at the stations closed to oil
industry were generally higher than that at the stations far from any oil-related activities. In both
locations, the oil contens were measured to be higher during high tide when compared to low tide. The
increase of oil content in the waters was followed by the decrease in diatom abundance. Simple linear
regression analysis indicates negative correlation between oil content and diatom abundance (Y = 2620 –
3000X; r = 0.4878and Y = 3546 – 5885X; r = 0.9110 in Sungai Pakning and Y = 3098 – 1947X; r =
0.7113 and Y = 2775 – 2152X; r = 0.3347 in Selat Lalang respectively ) during high and low tides.
