We did a flat walk one day in an area renown for the driftwood that washes up that has floated all the way from Siberia. Even if you look at a globe and see the direct route it can take, Siberia is a long ways away. On an island lacking in trees the wood is valuable and collected, less now than in the past, but we still saw some fjords where it was stacked up and ready to be hauled away for firewood or building material.
One aspect of Icelandic culture is the lack of litter; it's almost nonexistent. Except in this region it washes up from the ocean along with the driftwood, mostly plastic associated with fishing or boats.