Nine months later, debris fields from the aftermath of the tsunami in Japan on March 11 last year are no longer visible. Winds and ocean currents scattered items in the massive North Pacific Ocean to the point where debris is no longer visible from satellite.  Vessels regularly traveling the North Pacific have reported very few sightings. 

Computer models run by NOAA and University of Hawaii researchers show some debris could pass near or wash ashore in the Northwestern Hawaiian Islands (in the Papahānaumokuākea Marine National Monument) as early as this winter, approach the West Coast of the United States and Canada in 2013, and circle back to the main Hawaiian Islands in 2014 through 2016.

Researchers caution that models are only predictions based on location of debris when it went into the water, combined with historical ocean currents and wind speeds.

Conditions in the ocean constantly change, and items can sink, break down, and disperse across a huge area. Because it is not known what remains in the water column nor where, scientists can’t determine with certainty if any debris will wash ashore.

The worst-case scenario, according to NOAA is boats and unmanageable concentrations of other heavy objects could wash ashore in sensitive areas, damage coral reefs, or interfere with navigation in Hawaii and along the U.S. West Coast. Best case? The debris will break up, disperse and eventually degrade, sparing coastal areas.

Debris will not go away completely, even in a best-case scenario. Marine debris is an ongoing problem for Hawaii and West Coast states, where garbage and other harmful items regularly wash up on beaches, reefs and other coastal areas. 

This article comes, shortened, from NOAA