Microplastics on the Portuguese coast

Marine anthropogenic litter was analysed in eleven beaches along the Portuguese coast, over a two-year period (2011 - 2013). Of all collected items, 99% were plastic and 68% were microplastics (MP; 1-5 mm in diameter). Higher MP concentrations were found in winter/autumn, near industrial areas and/or port facilities and in beaches exposed to dominant winds. Resin pellets (79%) were the dominant category close to industrial areas and high concentrations of fragments and polymeric foams were found near fishing ports. The most frequent pellet size classes were 4 and 5 mm (respectively 47% and 42%). Results suggest that MP have predominately a land-based origin and are deliberately discarded or accidentally lost in watercourses and/or coastal areas. A combination of measures within stakeholders, namely industry and fishing sectors and share of good practices are needed to prevent marine anthropogenic litter.