Microplastics in Digestive System of Little-black cormorant (Phalacrocorax sulcirostris) in Pulau Rambut Sanctuary

Abstract

Microplastics have been found in many seabirds in various areas in the world, but there has been no report from Indonesia. The objective of this research was to discover whether there were microplastics in the Indonesian Seabirds, represented by the Little-black cormorant (Phalacrocorax sulcirostris). The study site was Pulau Rambut Wildlife Sanctuary, a small island in Jakarta Bay, where a big colony of the cormorants' nests together with other waterbirds. The gastrointestinal tract of a sample Little-black cormorant was collected to find macroplastic, mesoplastic, or microplastic. Microplastics were detected through NaCl dilution, followed by observation using 10x10 magnification and SRCC. There was no macroplastic and mesoplastic found in the sampled bird. As for microplastic, 16 microplastic particles of different types, sizes, and colours were found, giving an estimation of 320 particles/bird. Microplastic film type were dominant (75.0%), followed by fiber (18.7%) and fragment (6.3%). The size of the microplastic was mostly (68.7%) between 100-1,000 μm. Color-wise, more than half (56.2%) were transparent. Other colors found were red (18.7%), black (12.5%), yellow and blue (6.2% each), no brown or green.