STEROL AS AN ANTHROPOGENIC MARKER IN SURFACE SEDIMENTS OF KAPAS ISLAND, TERENGGANU

Abstract

Kapas Island is a little tropical island in the South China Sea which is well known as one of the main tourist attractions located in Terengganu, Malaysia. This study describes sterol distribution using sewage sterol data collected from surface sediments to indicate the presence of anthropogenic effects on the coastal environment of Kapas Island. Samples from a total of 15 sampling stations were collected, extracted and analysed using Gas Chromatography-Mass Spectrometry (GC-MS). Terrestrial and sewage inputs of 7 sterol compounds were identifid to evaluate the impact of human disturbance in the marine sediment. The results indicate that the concentrations of sterol compounds ranged from 6.19 µg/g (dry weight) to 9.88 µg/g (dry weight) in the surface sediments. Faecal sterol content was used as a tool to identify sources of organic material by using the ratio between faecal sterols and terrestrial input caused by anthropogenic effects as a means to evaluate pollution levels and marine ecosystem stability. The results of the analyses indicated low concentrations and ratios of sewage sterols. Most sediment in the study area contains low levels of sewage contamination, which is probably due to the sand that characterizes the sediment. Sandy sediments are less likely to retain organic material, thus resulting in low concentrations of sterol compounds in the sediments. Nevertheless, the presence of sterol compounds is an indication of the human imprint/presence at Kapas Island.