Hundreds of species with Japanese origin now in US

Hundreds of species with Japanese origin are now in the US.

Researchers say nearly 300 species of fish, mussels and other sea critters "hitchhiked" across the Pacific Ocean on debris from the 2011 Japanese tsunami.

That's a 4,800 mile trek, the largest and longest marine migration ever documented.

Researchers say they could be a problem if the critters take room, pushing out native species.