Based on the items most often collected on beaches, it is commonly claimed that the majority (80 per cent) of marine litter is linked to land-based sources. The top ten most collected items are remnants of consumer products or their packaging released into the environment close to large urban or tourist areas (International Coastal Cleanup, 2014). However, the figure of 80 per cent should be used with caution because there is a lot of variation in the composition of litter depending on the location. Marine litter composition data from different sites worldwide show that sea-based sources are sometimes dominant over land-based sources, especially in locations further away from large population and tourist centres (Galgani et al., 2015). The composition of beach litter collected in remote locations may in fact represent an integration of the sources over larger areas and longer time periods. Based on systematic monitoring of 175 sites over several years, the US National Marine Debris Monitoring Program attributed 49 per cent of the items collected to land-based sources, 18 per cent to sea-based sources and 33 per cent to non-identified sources. Regional variations were recorded, with sea-based sources largely dominating on the northernmost east coast of the US (42 per cent sea- based vs. 28 per cent land-based) and Hawaii (43 per cent sea-based vs. 22 per cent land based) (Sheavly, 2007).
From collection: Marine Litter Vital Graphics