Microplastic Contamination in the Tissue of Giant Freshwater Prawns Macrobrachium rosenbergii, Thailand

Microplastics are everywhere and may be harmful to the biota environment. This study investigated microfiber contamination in giant freshwater prawn tissues, one of Thailand’s economic species. The prawn samples were taken from the Trang River in southern Thailand in September 2022. Three tissue sections (head, middle, and tail) of 60 prawns were studied and the samples were digested with 10 % potassium hydroxide (KOH) solution. We utilized a stereomicroscope to study the microplastics and Fourier transform infrared spectroscopy (FT-IR) to determine the types of polymer. There were 3.50 ± 0.34 microfibers in the head per 5 g weight, 2.87 ± 0.29 per 5 g weight in the middle, and 3.10 ± 2.28 per 5 g weight in the tail. Fiber appearance is obvious, the predominant color is blue, the most common size is in the range of 101-500 µm, and the polymer type found is cotton rayon polypropylene (PP). The correlation analysis of microfiber content (in the stomach and intestine), carapace length, abdomen length, stomach weight, and body weight in giant freshwater prawns was not correlated with tissue microfiber content (p > 0.01). It was found that the number of microplastics in giant freshwater prawns was not significantly different (p > 0.05) among the 3 sections of prawn tissue (head tissue, middle tissue, and tail tissue). HIGHLIGHTS Digestion of prawns with KOH 10 % Microplastic contamination was discovered in giant freshwater prawn tissues Fiber shape was most found in giant freshwater prawns The polymer type discovered is cotton rayon polypropylene GRAPHICAL ABSTRACT