Microplastic litter composition of the Turkish territorial waters of the Mediterranean Sea, and its occurrence in the gastrointestinal tract of fish

Micro-and macro-plastics in marine species from Nordic waters

“…On the other hand, larger fish may be better at excreting plastic from their stomach due to their physiology. Although, fish length, nor the mass of fish, did not appear to have any correlation with the number of ingested particles (Güven et al, 2017).…”

“…This highlights a significant need for increased studies on more species from pelagic and demersal habitats. Pelagic fish, as studied by Güven et al (2017), contained higher numbers of plastics regardless of whether they are predatory species or not. Uptake of microplastics could be related to distance from urbanised locations, sources of input or sources of accumulation in the environment.…”

“…As the data on microplastics in the Nordic environment are less than substantial, increased knowledge of microplastic behaviour and spatial spread is required. Trophic level has also been suggested to impact plastic ingestion (Boerger et al, 2010) but a recent study found that the trophic level did not influence the quantity of microplastics ingested (Güven et al, 2017). However, secondary ingestion may impact ingestion levels; since prey species may have already ingested plastic, and they may act as a vector for transfer of plastics between trophic levels.…”

“…It has been suggested that the levels of food in the gastrointestinal tract, or stage of digestion, may affect microplastic presence (Bråte et al, 2016). Therefore, monitoring would only provide levels as a snap shot in time (Güven et al, 2017; see section 5 for more discussion on this).…”

“…Recent research has also found that the levels of plastics found in fish depends on if the whole digestive tract is analysed, or just the stomach. Güven et al (2017) found 1.81 microplastic particle per fish in the intestines, and this means that studying just the stomach and not the entire digestive tract, can lead to underestimation of the plastic ingestion levels of fish.…”