Animals, Plants Rafted Across The Pacific After Japan's 2011 Earthquake

NPR's Ailsa Chang talks with Greg Ruiz, a marine ecologist at the Smithsonian Environmental Research Center, about nearly 300 Japanese marine coastal species that traveled across the Pacific Ocean.

AILSA CHANG, HOST:

After the 2011 earthquake in Japan, the tsunami it created swept coastal animals and plants out to sea. They became passengers onboard garbage. And over the years, they have made their way to North America. Their ability to survive the journey surprised scientists, and these scientists have been studying this multi-species flotilla.

A new study has just been published in the journal Science. It documents the voyage of nearly 300 Japanese marine coastal organisms. And to talk about these creatures, we're joined now by one of the study's authors, Greg Ruiz. He's at the Smithsonian Environmental Research Center. Welcome.

GREG RUIZ: Thank you.

CHANG: Tell me what's new in this paper.

RUIZ: What's really new and surprising in this study is that we documented a wide-scale mega-rafting event where coastal organisms were able to hitch a ride on debris items that were swept offshore from Japan and transmitted across the entire Pacific Ocean. And the remarkable thing about this is that these coastal organisms are not known to do this broad-scale trans-ocean dispersal. And to our knowledge, this is really the first documentation of this large-scale transport event for coastal organisms in open ocean.

CHANG: So what do these organisms look like? Can you just describe them for me real quick?

RUIZ: Sure. It's a wide range of - actually spectacular range of organisms from coastal habitats, the ones that we know and love - barnacles, crabs, sea stars. And the remarkable thing is the large number - the community of organisms across a wide spectrum of organism types. We also found organisms that probably wouldn't be recognized so commonly, things that are quite bizarre.

CHANG: What do they look like?

RUIZ: Some of them are like small sea anemones, but they live inside of muscles - on the gills of muscles.

CHANG: With all these huge storms that have been happening lately, will we be seeing more of this kind of thing - debris carrying lifeforms to distant lands?

RUIZ: Yes. We think that that's one of the take-home messages of the study - that certainly marine organisms have been able to be raft in an open ocean in the past but usually with rafting on things like logs, different types of debris that would essentially dissolve under them, whereas now what is washed offshore are plastic items, fiberglass, things that persist for a really long time.

CHANG: Right.

RUIZ: And so suddenly there's an opportunity for those organisms to not only colonize but to ride those rafts to great distances that were not possible historically.

CHANG: Four years ago, a Japanese dock that was encrusted with life - it washed onto an Oregon beach. And I was struck by the headline we gave it on npr.org. "Is Japanese Dock A Noah's Ark Or A Trojan Horse?" I want to ask you. Is this phenomenon a good thing or a bad thing - when new species get introduced to new places?

RUIZ: Well, the phenomenon is what we refer to as biological invasions - when species are introduced to a region where they were not previously present.

CHANG: Invasion sounds like a bad word.

RUIZ: Well, it has that connotation, but we don't mean it as a bad word necessarily. It's how islands are colonized from mainland species rafting across the ocean or by dispersal and other ways. But the thing that's happened in modern time is that the rate and the magnitude, the scale of those transfer events has increased.

And so what we see in this case is that a new mechanism has come into play. We don't know whether those species have actually colonized on the West Coast of North America. We believe that there is a very good chance that some of them have. And we don't really have a good sense of what the possible consequences may be.

CHANG: That's Greg Ruiz of the Smithsonian Environmental Research Center. Thank you very much for speaking with us.

RUIZ: Great, thanks very much.

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