Researchers say nearly 300 species of fish, mussels and other sea critters hitchhiked across the Pacific Ocean on debris from the 2011 Japanese tsunami, washing ashore alive in the United States.

The researchers and outside experts say it the largest and longest marine migration ever documented. The scientists and colleagues combed the beaches of Washington, Oregon, California, British Columbia, Alaska and Hawaii and tracked the species to their Japanese origins.

Study lead author James Carlton at Williams College says this could be a problem if the critters take root, pushing out native species. He calls it “ecological roulette.”

Scientists found 289 separate Japanese species made the 4,800 mile trek across the Pacific to the West Coast.

The study is in Thursday’s journal Science.

The Washington Department of Fish and Wildlife has documented several responses to debris along our coast. Find more details on their Tsunami Debris Program website.

Japanese Tsunami Marine Debris Response
June 15, 2012 –
Skiff at Cape Disappointment
May 10, 2015 –
Fiberglass boat
December 14, 2012 –
Large cement dock
May 16, 2015 –
Fiberglass boat
March 22, 2013 –
Fiberglass boat
May 20, 2015 –
Fish Attraction Device Buoy & Other Debris
January 15, 2014 –
Fiberglass boat
March 26, 2016 –
Fiberglass boat