22 meter, 150 ton CONCRETE pier from Japan tsunami on Oregon beach

Though most of the debris from the Japanese tsunami has sunk, approximately 1.5 million tons of it is still floating along in the Pacific.  This floating pier broke off from Misaya in northern Japan during the earthquake/tsunami.

Apparently, foreign species from starfish to microbes have clung on to the debris.  When introduced to the American West Coast, ecological havoc may result.

Source.