The first observation of the presence of microplastics in wild common bleak (Alburnus alburnus L.) and standardization of extraction protocols

The presence of microplastics (MPs) in the gastrointestinal tract, muscle, and whole-body samples of common bleak Alburnus alburnus L. from Gruža Reservoir (Central Serbia) was studied for the first time. Different protocols for MPs extraction were applied to determine the most efficient one. The study aimed to modify existing protocols to be cost-effective, efficient in digestion, and with no detrimental effect on potentially present MPs polymers. In this study, the digestion with 10% KOH during 48 h at 40°C was efficient for the gastrointestinal tract and muscle. Digestion with 10% KOH during 72 h at 40°C was the most efficient for whole-body samples. The usage of NaClO proved successful in digestion of the gastrointestinal tract overnight at room temperature. Fibers detected in the samples are assumed to be of plastic origin. The general goal was to establish a protocol for extracting MPs from fish tissue in wild populations to obtain results and determine the degree of pollution.Publishe