Thesis submitted to Universiti Teknologi Brunei for the partial fulfilment of the requirements for the degree of Master by Research in Water Resources Engineering ABSTRACT
This dissertation investigates debris reaching the coast of Brunei Darussalam along the South China Sea. Studies having standard results about debris for many coastal areas around the globe are still missing including 161 km long Brunei coast. In this study, six representative beaches classified into three groups namely A (recreational based), B (riverine estuaries) and C (with sea based litter) were selected. Accumulation survey method was used for debris collection from selected sites. Collected debris have been investigated physically (number. weight, size and colour), chemically (qualitative analysis) by using FTIR spectroscopy and statistically to address the existing situation of the coast along Brunei Darussalam. The area selected for study was 110 x 30 m² for group A, 110 x 27 m² for Lumut beach and 110 x 25 m² for Seri Kenangan beach in group B and 110 x 25 m² for group C depending upon the beach location. Results show that 90.02% of whole debris found was plastics by number followed by lumber (3.29%), rubber (2.52%), miscellaneous (2.37%), metal (0.73%), glass (0.70%) and fibre (0.36%). While by weight metal was the leading portion (39.30%) followed by plastic (39.12%), lumber (8.38%), rubber (5.74%), miscellaneous (4.91%), glass (2.18%) and fibre (0.37%). Plastic material was further characterized by size (micro (≤5mm), meso (5-20 mm), macro (21-100 mm) and mega (> 100 mm) and colour (transparent, coloured, white and black) due to its abundance, long life and severe adverse impacts. By size macro plastics were leading part (55.65%) by number followed by mega (24.95%), meso (13.96%) and micro (5.44%), while by weight 73.54%, 19.35%, 4.55% and 2.56% respectively. On the basis of colour, the most dominant part was transparent (35.83% by number and 44.94% by weight) followed by white (31.27% by number and 24.95% by weight), coloured (30.63% by number and 21.19% by weight) and black (2.27% by number and 8.92% by weight). Indicator items were used to find the sources and distribution trends of plastic material along the coast. Tourism and land based debris was found more dominant during this study. Mitigation strategies were proposed on the basis of different practices in the world, local weather condition and distribution trend of debris in Brunei Darussalam. As a consequence, introduction of engineering and management practices simultaneously can reduce the load of debris. The information gathered and manipulated in this dissertation will help the Government of Brunei Darussalam and UNEP to conduct more research and to take environmental management decisions in future.