Microplastics Contamination in Environment and Marine Animals at Kodek Bay, Lombok, Indonesia

In this study, microplastics (MPs) contaminations in Kodek Bay, North Lombok, West Nusa Tenggara, Indonesia, were investigated from water, sediment, and marine animal samples to evaluate the impact of waste discharges from anthropogenic activities and river run-off around the bay. The samples were collected from three site categories: port, residential area, and aquaculture floating net cages. Water quality in each site was also observed. Three marine animals with different feeding regimes were selected to assess MPs contamination, including pompano (Trachinotus blochii), crab (Ocypode kuhlii), and oyster (Crassostrea sp.). A series of extraction protocols followed by stereomicroscope observation were conducted to identify the MPs' abundance, form type, and color. Next, the MPs polymer type was characterized using Fourier Transform Infra Red (FT-IR) at a frequency range 4000–400 cm-1 resolution 4.0 with Bruker Alpha II spectrometer. The results showed no significant difference (P < 0.5) in MPs abundance in water (15.75–20 part.L⁻¹) and sediment (10.25–12.3 part.kgDW⁻¹) samples between the sites as well as between marine animals (23.20–27.03 part.ind⁻¹). Various MPs types and color proportions were observed from water and sediment from different sampling locations and marine animal body parts. The MPs form types found include fragment (6–58%), film (7–49%), fiber (2–25%), and pellet (20–78%), while based on the MPs particle colors, the proportion were black (14–78%), yellow (7–33%), blue (2–25%), red (8–30%) and green (2–30%). Analysis of functional groups and polymers from water, sediments, and marine animal samples indicated the presence of PS (Polystyrene) and PE (Polyethylene). The study results indicated widespread MP contamination in the Kodek Bay area. The results serve as a scientific-based recommendation for policymaking to further prevent MPs contamination in the area.