Microplastics in fishes as seabird preys in Jakarta Bay Area

Abstract

There has been some growing research on plastics in fishes as human food in Indonesia, but none linked to fishes as seabirds' prey. The objective of this research was to reveal whether there were microplastics in fishes as prey of little-black cormorant. The study site was the coastal area of Pulau Rambut Wildlife Sanctuary in Jakarta Bay, where the cormorants search for fish food. Fish samples (12-16.8 cm, 5 species; n=8) were collected by using fish-rod, at the usual fishing area of cormorants along the southern coast of the reserve. Gastrointestinal tracts of the samples were observed to find macro, meso and microplastic. After NaCl dilution, followed by observation using SRCC and microscope (10×10 magnification), followed by grouping based on type, color, and size. No macro or mesoplastic found. Total of 110 microplastics particles were found from all samples (range 7-26 particles/fish), with Lutjanus vitta having the highest number (15-26 particles/fish). Film (2-21 particles/fish) and fiber (1-10 particles/fish) were found, but no fragment. Transparent microplastics were found the most (57.3%), followed by blue (26.4%), black (10.0%), and red (6.4%). The size of the microplastic found were mostly (64.5%) between 100-1.000µm. A more intensive research is needed, as these sampled fishes might also consumed by human.