Characteristics and abundance of microplastics in bean clam (Donax sp.), Setawar Beach

Setawar Beach, located in Tanjung Irat Village, Singkep, Lingga Regency, Riau Islands Province, is an area susceptible to plastic waste pollution from domestic waste and fishing activities. Therefore, this research aimed to analyze the characteristics, type, color, and abundance of microplastics in Bean clam (Donax sp.). Purposive sampling was used to obtain Bean clam samples of size 2 mm to 5 cm during low tide, without temporal replication. The results showed that the sample was subjected to an initial analysis including the separation of organic materials using a 30% H₂O₂ solution, followed by a secondary analysis using ZnCl₂ and Fe₂SO₄ solutions. Finally, the process examined the shape and quantity of microplastics under an electron microscope. The highest density and abundance of microplastics were found in the medium and large size, 27.3 ind/m² and 44.9 particles/gram dry weight, respectively. This was connected to longer lifespan and higher filtration capacity of large individuals. The most common types of microplastics were fiber and film, with a total of 102.87 and 5.41 particles/gram dry weight, respectively. The correlation between clam density and microplastic abundance was very low (r = 0.12, p > 0.05).