Seasonal variation in the correlation between beach wrack and marine litter on a sandy beach in West Iceland.

Coastal plastic pollution is a global problem, it affects local ecosystems, and can have economic and social implications. Plastic pollution is pervasive at high latitudes but there is a lack of data on the spatial and temporal amount of marine litter entering coastal systems. In this study, a seasonal accumulation survey of anthropogenic debris and beach wrack was conducted for the first time in Iceland. One hundred data collections were performed on a coast in the Snæfellsnes peninsula throughout one year. Of all the debris retrieved, over 9000 items (0.2 to 50 cm), 78.5 % were plastics. Beach wrack correlated strongly with the quantities of plastic debris entering the coastal environment (R > 0.9; p < 10), with a different slope for each season. The presence of beach wrack informed important daily and spatial fluctuations in the quantities of plastic debris, while seasonal fluctuations demonstrated higher arrival rate of plastic in autumn and winter.