LAUSR

Abstract Various studies show a contamination of the marine environment with microplastics due to the material persistence and a resulting accumulation. Right now, the environmental impact of microplastics is not fully determined and in order to obtain further information on contaminated areas, water surface samples and (deep sea) sediment from the Atlantic Ocean south of Algarve Coast (Portugal) were taken and analysed. Microfibres, 3 black fibres, were visually detected in 2 of the 20 sediment samples without verifying their polymeric identity. Assuming that they are microplastics, concentration from 0.00–0.29 particles/g dry sediment result. In the eleven water samples, 81.8% contained microplastics including polymeric identification (0.00–14.09 particles/m3) with an average contamination of 1.36  ±  4.03 particles/m3. A significant positive correlation between the microplastic concentration in the water and the average water depth during sampling was identified. This regional study is one of a few that analysed also deep sea sediment and provides results about microplastics as anthropogenic contaminants south of the Algarve coast.