Since many species were just recorded on one piece of debris, however, the authors estimate that the real number of species that hitched a ride across the Pacific is much higher. "Now, plastic can combine with tsunami and storm events to create that opportunity on a large-scale".
Steves says what is being learned on the West Coast could apply to other parts of the world.
The difference? Plastic, foam, and other human-made materials that won't sink or biodegrade.
The tsunami which had impacted adversely Japan on March 11, 2011, after an natural disaster of magnitude 9.0 had resulted in swiping of tons of plastic wastes to the ocean. Not only did that cause devastation inland, it swept millions of pieces of debris out to sea. The ecological impact of plastic waste is a pertinent concern as ever.
The team has found 289 different species so far, including crabs, clams, slugs and star fish.
Almost 300 species ended up on American beaches after being swept across the Pacific on flotsam powered by the catastrophic tsunami that struck Japan six years ago. We never thought they could live that long, under such harsh conditions. "This is one other dimension and effect of plastics and man-made material that deserves attention".
Worms, hydroids including sea anemones and jellyfish, crustaceans and bryozoans which have the habit of colonizing in the underwater beds were also found among the new guest species.
None of these species have established proper colonies in the U.S. yet, but that can take time, the researchers say.
So far, the scientists have found no evidence of Japanese species establishing themselves on the West Coast, although it is a process that can take many years.
Almost 20 per cent of the newly arrived species were capable of reproduction and still new species continued to arrive this year, explained marine ecologist Jessica Miller, adding: "We were able to not only identify this unique suite of species but, in some cases, examine their growth and ability to reproduce which provides useful information on how they fared during their transoceanic voyage".
As astounding as the coast-to-coast trip is, the team is keen to point out the environmental damage we're doing by using the oceans as a garbage dump: we might not be able to stop earthquakes, but we can cut down on plastic waste.
Some even reproduced as they moved eastward.
"When we first saw species from Japan arriving in OR, we were shocked".