Microplastic accumulation in Lake Van aquate ecosystems

The impact of microplastics, plastic particles smaller than 5 mm, on ecosystems and living organisms is an issue of increasing concern. As part of this study, sediment samples were collected from 3 different stations in 4 counties on the shore of Lake Van in October 2021 and analyzed for the presence of 4 different types of plastics/microplastics, LDPE, PP, PS, and PET. In the collected samples, methods such as sieve filtration, organic matter removal, and density separation were used to isolate microplastics. After isolation of microplastics from the samples, visible microplastics were detected and photographed in the samples concerned, bacterial density was measured by microbiological analysis, microplastic particles were quantified by precision balance, color and shape of microplastics were examined by stereomicroscope, microplastic particles were identified by FTIR spectroscopy. As a result of the investigation, microplastic particles were detected in the sediment samples we studied, which are elements of the Lake Van aquatic ecosystem. The FTIR spectra obtained from the studied sediment samples were compared with the reference peaks in the KnowItAll virtual library (Informatics System John Wiley) and the peaks on the Spectroscopy Online website, and as a result of this comparison, PS was identified as the dominant polymer type. During the morphological examination with a microscope, it was found that fragments dominate among the microplastics and the color is white/transparent. Examination of the size of the microplastic revealed that microplastic particles with a size of 3-5 mm dominated. Microbiological analysis showed that in the examined water samples of lakes Van1 and Erciş1 E. coli was detected (6/2 100ml/kob), with the total number of coliform bacteria being highest in Erciş2. About 1/3 of the fish caught in the inland waters of Turkey is landed; the detection of microplastics in the habitat of the pearl barbel, an endemic species living in the aquatic ecosystem of Lake Van, which is an important source of life and food for the local population, is of great concern. In this work, information was obtained on the presence of microplastics in the sediment, one of the elements of the aquatic ecosystem of Lake Van. The definite presence of microplastic in the sediment of Lake Van should be carefully studied in the aquatic ecosystem of Lake Van in terms of the environment, food safety and human health.