Marine and macroplastic litter monitoring and strategic recommendation for reducing pollution: case study from Semarang City

Abstract

Indonesia is one of the largest contributors to global marine litter deposition, given its high population and the largest archipelagic country. The increasing problem of plastic littering has recently attracted the attention of researchers. This study aims to identify marine and macroplastic litter in Semarang City. A field survey was conducted by dividing the beach into 18 sampling grids, each with an area of 1 × 1 m2. A literature survey was also conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology to identify literature that can be used to develop recommendations. The results showed that 6.26–11.16 grams/m2/ day of marine litter and approximately 1.61–4.89 items/m2/day of plastic litter would be deposited on Semarang City beaches. The greatest contributors to macroplastic litter were polypropylene (PP) and low-density polyethylene (LDPE), which should be considered for further intervention. Strategic recommendations were developed based on an in-depth literature survey and best practices in the current field. These also include recommendations that can be used as a reference by policymakers and other stakeholders to reduce marine pollution. The results of this study are expected to provide a multiplier effect on reducing marine pollution for the city.