The Relationship Between Macroplastic and Large-Microplastic Abundance in the Northern Coastal Region of West Peninsular Malaysia

Abstract

Several locations representing recreational area, tourist spots and fish landing grounds were selected in the northern coastal region of Peninsular Malaysia for L-Microplastic (L-MP) data collection. Marine litter samples were collected during HWS and LWN tidal regime. Quadrats of 50 cm x 50 cm were used to collect sediment from surface to 5 cm depth for microplastic analyses. A comparison between macroplastic and L-MP showed a significant relationship with R2 =0.9579 where linear regression computed resulted in y = 26.388x + 0.051, where y: microplastic (kg/m3) while x: macroplastic (kg/m3) for Perlis sampling region. The linear regression obtained for Penang island is y = 0.1248x + 0.0854 with R2=0.9036. Both results showed a significant difference where computed P-values were both <0.05. Findings from Penang island region demonstrated possibility of macroplastic and L-MP abundance relating to tidal condition, where during neap tides more plastics are settled on the beach zone as opposed to during spring tides mainly because of the difference in water volume and movement dynamics. Largest marine litter composition was plastic, followed by fabric and rubber. Although recent plastics used are of biodegradable grades meaning it breaks down into smaller sizes through exposure to sun, hydrolysis and microorganism reactions over time, these L-MP might further degrade to nanoplastic in size. The smallest microparticle reportedly detected in the oceans at the present is 1.6 µm in diameter. Further breakdown of microplastics is imminent and will be difficult to detect as these nano-sized plastics enter the food chain resulting in health risks. Based on this, the UN-SDGs directly affected will be SDGs 3, 6, 12, 14 and 15. KEYWORDS: microplastic, plastic, marine litter, marine debris, health risk, biodegradable