<i>Astacus leptodactylus</i> is collecting microplastics in dam reservoir: a new record for Türkiye

With the growing understanding of the importance of microplastic (MP) pollution, which has significantly impacted several aquatic ecosystems of the world. The diverse range of aquatic ecosystems, including seas, oceans, freshwater bodies and wetlands, coupled with the rich variety of species inhabiting them, continually provides new insights into the daily impacts of MP pollution. In this study, it was planned to determine the presence and identification of MP in the tissues (muscle, gastro-intestinal tissue [GIT]) and gill) of crayfish (Astacus leptodactylus), which is an important economic species in the world and in Türkiye and known as the ‘ecosystem engineer’. For this purpose, 20 specimens of A. leptodactylus were sampled from Keban Dam Lake (Elazığ, Türkiye), then MP digestion was performed on the determined tissues and µ-Raman spectroscopy was used to determine the polymer type in the particles obtained. In the findings obtained, MP was not found in muscle tissue, while 1.95 particles/individual, and 1.30 particles/individual MP were detected in GIT and gill tissues, respectively. The dominant MP color in the GIT (51.3%) and gill (57.7%) tissues of crayfish is black. The dominant MP shapes in crayfish tissues were determined to be fiber at the highest rate (GIT: 64.1%, gill: 57.7%). When the sizes of MPs were evaluated, it was seen that they were more distributed in the range of 100–500 µm. The most common polymer type was polyethylene (30%), while the least common polymer type was polydienes (5%). The findings of this study, the first of its kind in the field, showed that MP accumulation in crayfish was lower compared to studies conducted in fish in the same region.