Microplastic content of Kutum fish, Rutilus frisii kutum in the southern Caspian Sea

Microplastic Pollution in the Gastrointestinal Tract and Gills of Some Teleost and Sturgeon Fish from the Caspian Sea, Northern Iran

“…However, because we did not study the morphology, size, or filtering system of the gills, we cannot speculate about the role of the gills in microplastic accumulation; further studies need to be performed to elucidate the relationship between microplastic abundance and the gill filtering system. Abadi et al (2021) did not find any significant difference between microplastic pollution and R. kutum size (length and weight) in the Caspian Sea and suggested that all individuals regardless of size take up microplastics. Koongolla et al (2020) investigated fish species from Beibu Gulf, China, and did not find a positive correlation between microplastics and body length or wet weight.…”

“…Rutilus kutum is also a carnivorous fish, feeding on benthic aquatics such as Balanus sp., Cerastoderma lamarki , shrimps, and crabs (Afraei Bandpei, 2010). Consequently, microplastics can be ingested and accumulated in their prey and then transferred to the fish through the food chain (Abadi et al, 2021). Cyprinus carpio is an omnivorous fish that can uptake microplastic particles from sediment and surfaces of plants during feeding on benthic animals (Rasta, Sattari et al, 2021).…”

“…Fishing gear, textiles, and domestic wastewater effluents (especially from laundry washing) are probably the major sources of these ingested fibers (Nematollahi et al, 2020). In addition, undigested food and digestive enzymes in the fish GIT, which act as natural abrasives, may break fibers down into microfibers (Abadi et al, 2021). Several studies have also reported a higher abundance of fibers than other microplastic shapes in fish tissues from different aquatic ecosystems (Arias et al, 2019; Horton et al, 2018; Neves et al, 2015; Nithin et al, 2022; Zhang et al, 2020).…”

Methods of Analyzing Microsized Plastics in the Environment

“…Microplastics generally have no luster and are identified based on physical reaction properties, such as specific elasticity or hardness [24]. Furthermore, microplastics usually take the form of fibers, fragments, and beads in the environment [39]. About 70% of microplastic samples are transparent [40].…”

“…Additionally, components of additives, such as Al, Ca, Mg, Na, and Si, or antioxidants in microplastics are captured as markers and used for identification using EDS [25,32]. Determining the surface elemental composition of a particle can be useful for identifying carbon-rich plastics from inorganic particles [39,46]. However, SEM and TEM limit the number of samples that can be processed because the equipment is expensive, and sample preparation and inspection require significant time and effort.…”