Abstract:
The distribution of Total Organic Carbon (TOC) and Biological Oxygen Demand
(BOD) in sediment of Setiu Lagoon was studied. Four sampling field trips were
conducted at 14 stations. The mean and standard deviation values of TOC (total
organic carbon) in sediment during the first, second, third and fourth sampling periods
for the lagoon stations were 6.715±5.789 mg C/g, 7.149±5.589 mg C/g, 8.333±5.718
mg C/g and 8.269±0.049 respectively. The mean and standard deviation values of
biological oxygen demand (BOD) in sediment samples during first, second, third and
fourth sampling periods were 0.104±0.092 mg C/g, 0.500±0.118 mg C/g,
0.512±0.139 mg C/g and 0.466±0.121 respectively. While the mean and standard
deviation values for biodegradable organic carbon in sediment samples were
0.041±0.037 mg C/g (first sampling), 0.200±0.047 mg C/g (second sampling),
0.205±0.056 mg C/g (third sampling) and 0.187±0.049 mg C/g (fourth sampling). The
mean and standard deviation values for non biodegradable organic carbon in sediment
samples was 6.674±5.753 mg C/g (first sampling), 6.949±5.547 mg C/g (second
sampling), 8.128±5.665 mg C/g (third sampling) and 8.082±5.815 mg C/g (fourth
sampling). TOC and BOD5 reading was increasing significantly during Inter monsoon
and early northeast monsoon. But, there was slightly decreasing of TOC and BOD
concentration during fourth sampling (late Northeast monsoon). This might be due to
agricultural terrestrial run-off brought by inland rainfall during monsoon season
Nevertheless, Setiu Lagoon is still considering as an unpolluted aquatic system with
the organic matter.
