Microplastic pollution has been recognised worldwide and occurs at economic, social and environmental costs, with potentially high ecological impacts on marine ecosystems (Andrady 2017). In the Southern Ocean, Microplastics (MP) have been found in surface water and sediments, but little is known about the interaction with Antarctic fish (Waller et al 2017). With the contamination of remote marine areas by fragmented debris and increasing human presence in Antarctica (Tin et al 2009), the levels of MP pollution are likely to rise accordingly, a reason of concern for members of CCAMLR (Waller et al 2017). Hence, it is crucial to better understand the scale and fate of MP pollution in Antarctica, especially its potential uptake by living organisms, affecting other trophic levels. The master thesis aims at supporting the understanding of MP pollution in the Antarctic ecosystem through its potential occurrence in fish. Antarctic silverfish (Pleuragramma antarcticum) from the Antarctic Peninsula and the Eastern Weddell Sea are investigated. The objectives are to determine (i) whether MP are present in Antarctic fish (ii) whether the abundance of MP differ according to the geographic area (iii) whether the occurrence of MP differ between GIT and gills and (iv) the type of MP that are ingested by Antarctic fish. The gastrointestinal tract (GIT) and gills of 94 fish caught in 2014 and 2018 are analysed. Samples are treated according to the enzymatic digestion protocol of Cole et al. (2015) to dissolve the organic matter. Potential plastic particles ¿300μm are analysed with ATR-FTIR and particles between 10-300μm with μ-FTIR. To limit airborne contamination, preventing measures, such as working under a mosquito net, wearing cotton clothes, filtrating all liquids, carefully cleaning utensils, and negative blanks, are taken for each methodological step.