Aquatic environments are one of the final destinations for microplastics. In this review, a combination of systematic and narrative literature review was conducted to identify and summarise advances, gaps, and future directions in microplastic monitoring studies in the Turkish aquatic environment and in inhabiting aquatic organisms. A total of 62 peer-reviewed publications available on Web of Science were considered in the systematic review. Additionally, the current state of microplastic pollution in Turkish aquatic environments which includes marine and freshwater ecosystems, as well as aquatic organisms, and sources and characteristics of microplastics were reviewed narratively. Türkiye`s position on the global plastic treaty and mitigation practices were also addressed. Although an increase in the number of publications over time was observed, the number and extent of studies carried out in freshwater ecosystems are limited. Strict legislation should be enacted and enforced to tackle plastic pollution in Türkiye. Additionally, nationwide, long-term monitoring studies at sufficiently regular intervals in aquatic environments should be considered.

The marine ecosystem is severely threatened by microplastics. The entire marine environment of the Black Sea is contaminated with both macro- and microplastics but the contamination of the water column with this pollutant has received less attention. This study aims to obtain data on the microplastic abundance, and vertical and temporal distribution of the microplastics in the water column of Hamsilos Bay which is a natural protected area, and an important area for fishery and tourism on the Sinop coast in the Black Sea. This study was carried out for 12 months in 7 stations. Microplastic abundance varied among 5.58 ± 6.12–8.12 ± 9.17 pieces/m³ in and 1.74 ± 0.80–21.07 ± 3.84 pieces/m³ in stations. The dominant microplastics were fibre by shape (73.92%), 1–2 mm (28.35%) by size class, and blue (37.98%) by colour. The synthetic polymers in the examined microplastic samples of this study were PET (47%), PE (34%), HDPE (10%), PVC (7%) and PS (2%). The results of this study show that the coastal area is widely contaminated with microplastics. Microplastic pollution is an increasingly significant environmental issue that poses a threat to the Black Sea which is particularly vulnerable to microplastic pollution. The region is an important ecological hotspot in the Black Sea and this study can provide valuable insights into the extent of microplastic pollution and will contribute to the literature on the evaluation of microplastic pollution in marine ecosystems. These types of investigations; efforts to address the environmental challenges facing the Black Sea, including the development of programs to reduce pollution, increase sustainability, and support the protection of the region's natural resources, are crucial to its continuity.

The levels of Fe, Zn, Mn, Cu, Pb, Cd and Hg in the edible tissues of Mytilus galloprovincialis Lamarck, 1819 (Mediterranean mussel) picked up from the Black Sea coasts of Turkey have been determined by Inductively Coupled Plasma – Mass Spectrometer (ICP/MS) with a view to biomonitoring metal contamination in 2015. In this work, a statistically significant difference in the amounts of all studied heavy metals analyzed was noticed amidst sampling areas namely Igneada, Sinop, Samsun and Trabzon so that appraise welfare threat for mussel consumers, utilization M. galloprovincialis as biomonitors. The outcomes of this study were contrasted with the outlines stated by the Ministry of Agriculture, Fisheries and Food (MAFF), the Turkish Food Codex and Commission Regulation (EC) for the harmless consumption restrictions of Bivalves as seafood. Moreover, former works with mussels in the Black Sea countries were reviewed and a summary of heavy metal amounts in mussels from whole the Black Sea waters were presented. In general these available measurements clearly indicated a low level heavy metal in M. galloprovincialis in coastal waters of the Black Sea. In this study the concentrations (mg metal kg-1 wet wt.) of metals ranged from 18-35 for Fe, 8-27 for Zn, 2.8-4.5 for Mn, 0.5-1.8 for Cu, 0.06-0.31 for Pb, 0.04-0.10 for Cd and 0.03-0.07 for Hg. Considering human health with respect to the investigated heavy metals, the estimated daily intakes (EDIs) did not exceed the permissible intakes. No chronic systemic risk was found since total hazard index (0.521) were quite below critical value 1, and the carcinogenic risk for heavy metals did not exceed the tolerable values. Although there was no health risk to consumed mussels from the Black Sea riparian countries, the amount of mussels consumed is mainly unknown in countries; thus, consumption of about 1 serving of mussels from clean coastal waters per week is enough.