Occurrence of microplastics in herpetological museum collection: Grass snake (Natrix natrix [Linnaeus, 1758]) and dice anake (Natrix tessellata [Laurenti, 1769]) as model organisms

Abstract

Microplastics are plastic fragments with a size less than 5 mm in length. In addition to a threat to the marine environments where these are abundantly present, these have also started polluting freshwater ecosystems. However, the uptake of microplastics by living organisms differs depending on their habitats and feeding behaviors. We investigated the presence, size, type, and color of microplastics in the gastrointestinal tract contents of two water snakes, namely Natrix natrix and Natrix tessellata. The snakes were collected from different regions of Turkey and preserved as museum materials. Our results showed that fibers constituted the predominant polymer type in both snake species (94.7% for N. natrix and 87.9% for N. tessellata), whose dimensions ranged from 250 to 3750 mu m. We did not find any significant difference in the number of microplastics ingested between the two species. In addition, the uptake of microplastics did not relate to the size and weight of snakes. Microplastics were not consistently present all years, and similarly, these were not detected in all samples within the distribution area. These results could be attributed to the environment and diet of two snake species.