A total of 1,035 samples from 229 monitoring stations were analysed in 2006 (Table 5.3). As in previous years, the main contaminants of the coastal waters of all States that exceeded the IMWQS were total suspended solids (75%), Escherichia coli (55%) and oil and grease (35%). Figure 5.1 shows the trend of marine water quality contaminants from 2004 to 2006. Overall comparison showed an increase in E. coli, mercury and arsenic levels in marine waters and a decrease in total suspended solids, oil and grease, copper, lead, cadmium and total chromium in 2006 compared to the previous year.
Total suspended solids remained a significant contaminant of marine water with 100 percent of samples from Kedah, Perak and Negeri Sembilan exceeding the IMWQS. Other States recorded levels that exceeded the IMWQS by more than 35 percent, except for Pahang, where the level was 19 percent (Table 5.3).
For oil and grease contamination, Terengganu recorded the highest percentage (93%) exceeding the IMWQS, followed by Pahang (80%) and Negeri Sembilan (68%), while Sabah and Labuan was free from oil and grease contamination. E. coli contamination was recorded highest in Perlis and Kedah (100%), followed by Negeri Sembilan (83%) and Pulau Pinang (78%).
Heavy metals pollution was comparatively low with lead (Pb) exceeding the IMWQS by 20 percent, followed by mercury (18%) and copper (6%). Lead contamination was evident in Terengganu (86%), Kelantan (78%) and Perak (56%). Meanwhile, total chromium and cadmium pollution were recorded at two percent and arsenic (As) at one percent was detected in 2006.