Abundance and Distribution of Macro- and Mesoplastic Debris on Selected Beaches in the Northern Strait of Malacca

Plastics account for 60–80% of marine debris worldwide, and, in 2021, Malaysia was the 28th largest plastic polluter in the world. In light of this finding, the Malaysian government has launched the Roadmap Towards Zero Single-Use Plastics 2018–2030 and the Plastics Sustainability Roadmap 2021–2030 to reduce plastic pollution and implement a circular economy for Malaysia. A comprehensive database of the status of plastic pollution in Malaysia is needed to achieve this target. This study aims to record the presence of macro- (>2.5 cm) and mesoplastic (0.5–2.5 cm) debris at selected beaches in the northern Strait of Malacca. All study sites are publicly accessible beaches (Pulau Songsong, Teluk Aling, and Pulau Gazumbo) except Pulau Lembu, which is in a Marine Protected Area (MPA). The debris was collected from predetermined transects on the beach and categorised according to its form and economic market segments in Malaysia. Most of the macro- (53–75% of total mass) and mesoplastics (52–80% of the total number) were accumulated in the backshore area. Public beaches such as Pulau Gazumbo and Pulau Songsong recorded the highest abundance of macroplastics, with 7.32 g/m2 and 9.77 g/m2, respectively. Teluk Aling recorded the lowest abundance of macroplastics (3.58 g/m2) but the highest in mesoplastics (0.55 items/m2). Most of the macroplastics found were packaging plastics such as plastic bottles, containers, and polystyrene foam debris. Although Pulau Lembu is an MPA, the amount of macroplastics found was considerably high (7.17 g/m2). Based on the beach cleanliness index, Pulau Gazumbo (−3.99) was the dirtiest site, followed by Pulau Lembu (−2.92) and Pulau Songsong (−2.85), while Teluk Aling (−1.63) was the cleanest site, which can explain the amount of macroplastic debris found. However, all the study sites’ cleanliness may not be ideal, as the indexes were less than zero due to the low availability of waste bins and insufficient frequency of beach cleaning. This may not be able to curb the effects of high anthropogenic activities conducted in addition to uncontrollable natural factors.