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 plastic litter in the seas and oceans has become one of the major threats for environment and a wide range of marine species worldwide. Microplastics are the most common litters in the marine environment corresponding to 60-80% of the total litter in the world’s seas. The risk factor of plastics is inversely associated with the size of the plastic. In the present study, we reviewed the state of knowledge regarding the impact of plastic pollution on marine environment and marine species, assessing the ingestion incidences, elimination of plastics, interactions of plastics with other pollutants, and effects on photosynthesis. Records of marine species ingesting plastic have increased and begin to attract considerable attention. Metadata generated from the review of related papers in the present study was used to evaluate the current knowledge on the plastic ingestion by different marine species. The retrieved data from reviewed articles revealed that the ingestion of plastic by marine animals have been documented in more than 560 species including fish, crustaceans, mammals, sea turtles, bivalves, gastropods even in sea stars and limpets. The size of ingested plastics varied from species to species generally depending on the feeding behavior. Microplastics showed the highest number of bibliographic citations in the plastic ingestion studies. They are mostly ingested by planktivorous and filter feeder species. Meso, macro, and occasionally megaplastics are reported in marine mammals and sea turtles since they often confuse plastic for their prey. The sensitivity and size of the detected plastics may vary based on the analytical plastic detection methods.

Rivers are critical pathways of microplastic (MP) pollution to marine environments, yet their contributions to the Black Sea remain understudied. This study evaluates the abundance and characteristics (polymer composition, shape, size, and color) of MPs discharged from 29 rivers flowing into the southern Black Sea. Using a plankton net with a 200 μm mesh size, samples were collected from river mouths, revealing an average MP abundance of 9.63 ± 1.27 MP m⁻³, ranging from 1.03 to 29.8 MP m⁻³. Eastern Black Sea rivers exhibited significantly higher MP levels (11.0 ± 1.57 MP m⁻³) compared to western rivers (5.15 ± 1.25 MP m⁻³). Annual MP discharge to the Black Sea was estimated at 1.49 × 10¹¹ particles. Polyethylene terephthalate (PET, 59.3% ± 2.66%), polyethylene (PE, 20.8% ± 2.04%), and polypropylene (PP, 14.1% ± 2.36%) were the most common polymers, with PET and PE being significantly dominant. MP sizes ranged predominantly between 200–1000 μm, and fibers constituted the majority of shapes (64.1%), followed by fragments (28.3%). White (36.8% ± 1.93%) and transparent (30.9% ± 2.39%) MPs were the most prevalent colors. While no significant differences in MP characteristics were detected between basins (NMDS and ANOSIM), this study emphasizes rivers as major pathways for MP pollution in the Black Sea. These findings underscore the urgent need for targeted mitigation strategies to safeguard marine ecosystems and biodiversity.

Aquaculture emerges as a crucial solution for addressing the global food shortage of an estimated 10 billion people by 2050. In Türkiye, aquaculture plays a significant role in supporting the economy and ensuring food security. Over the past two decades, finfish production in Türkiye surged from 61,163 to 547,505 t, generating $1.7 billion in export revenue across over 100 countries. This growth has been driven by technological advancements, robust governmental support, and increasing global demand for aquaculture products. However, the sector also faces persistent challenges, including the need to enhance sustainability, mitigate ecological impacts, and manage finite resources. As Europe's leading fish producer, the Turkish aquaculture sector must continue to innovate and expand to meet the demands of a growing population. Despite the expanding research on Turkish finfish aquaculture, there is no comprehensive review that consolidates both scientific progress and sectoral developments. This study fills that void by combining a bibliometric analysis of 1958 scientific publications from 1983 to 2023 with an in‐depth sectoral evaluation, providing a holistic understanding of the Turkish aquaculture sector. The bibliometric analysis highlights key research areas, trends, and knowledge gaps, while the sectoral overview examines production trends, dynamics of the feed industry, technological innovations, and economic factors. It also addresses challenges such as climate change impacts, reliance on imported feed ingredients, and disease issues, discussing potential avenues for sustainable growth through innovation, policy reforms, and technological integration. This review serves as a valuable resource for researchers, policymakers, and industry stakeholders, offering insights into the current state and future directions of finfish aquaculture in Türkiye.