Tracing Industrial Microplastics Footprint in Fiji’s Marine Environment

This study investigated the presence of microplastics (MP) in drainage channels that carry stormwater and greywater runoffs from areas surrounding the industrial sites on Viti Levu, Fiji’s main island. Water samples were collected, digested with hydrogen peroxide, separated by density separation and filtered through an aluminum oxide Anodisc membrane filter (0.2 μm pore size) for particle recovery. The filter membranes were observed under a microscope for the presence, size and morphology of MP. 93.4% of particles ≥ 100 μm were confirmed as MP by ATR-FTIR. Across all sampling locations, an average MP concentration of 2.23 ± 0.78 MP L⁻¹ was observed, with the highest MP abundance (3.08 MP L^− 1) at Site 5 and the lowest (1.26 MP L^− 1) at Site 2. Fragments accounted for the largest number of MP (48.08%), followed by fibers (47.83%) and films (4.09%). Most of the MP (52.30%) were smaller than 500 μm. Polyethylene (PE, 46.29%) and polystyrene (PS, 33.76%) were the most prevalent polymers, reflecting their extensive use in packaging materials. These findings highlight the substantial role of industrial activities in MP contamination of the marine ecosystems. In Fiji, PS has been completely banned as a single use plastic, while PE is restricted under certain conditions. It is important to extend this ban to include PE and PS packaging materials to accelerate the elimination of these plastics from Fiji’s environment.