Abstract

Microplastics (MPs) represent one of the most significant global environmental issues due to their widespread use in consumer materials. The rapid growth of plastic product consumption leads to unmanaged waste separation and elimination. Microplastic contamination has been reported in diverse environments, up to 76% found in ocean habitats as well as animal tissues. Twenty-four samples of Cerberus rynchops, also known as dog-faced water snake, were collected from the mangrove forest area of Ao Thong Kham, Ban Nai Thung beach, Tha Sala, Nakhon Si Thammarat province. Stomach content analysis revealed that the prey abundances consisted of two main species: Boleophthalmus boddarti (64.1%) and Periophthalmus chrysospilos (29.0%), with an additional unidentified fish species (6.9%). The microplastic abundance in gastrointestinal tract of C. rynchops was 143 items in all samples, with an average concentration of 5.96 items per individual. The most prevalent colours of microplastics were blue (49.0%), followed by black (18.2%) and colourless (12.6%). The dominant particle size ranges were 1–500 µm (34.5%), followed by 501–1000 µm (41.4%) and 1001–1500 µm (13.8%). The most common polymers identified by Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy were polyester (53.3%) and polyethylene terephthalate (20.0%). The findings from this study indicate an increasing probability of microplastic contamination that may affect the life cycle and food chain within the ecosystem of this area.