Pictures: Tsunami Dock Is "Alien Mother Ship" of Species

Forcible Removal

Photograph courtesy Oregon Department of Fish and Wildlife

To deter the dock's non-native hitchhikers from establishing a foothold on Agate Beach, volunteers and staffers with the Oregon Department of Fish and Wildlife scrape the structure clean with rakes and shovels on June 7.

All the marine organisms were to be buried at elevations above storm-surge water lines—the lack of salt water will ensure that the life-forms will break down.

Invasive species biologist John Chapman said that, while invasives sometimes find their way across oceans, the journey of this "floating island" was unprecedented. So was the idea that hundreds of millions of organisms could survive in relatively food-poor, open-ocean waters without being picked clean by predators.

"We were caught flat-footed," said Chapman, of Oregon State University. "This was a close-encounter-of-the-fourth-kind type of event, where an alien mother ship from outer space lands on our shores."

(Related: "Japan Tsunami, Before & After: Zoomable Satellite Images.")

Published June 13, 2012

Armed, Not Dangerous

Photograph by Lynn Mattes

Gooseneck barnacles—such as this one, seen on the Japanese dock on June 6—are no strangers to northwestern U.S. shores. Other species on the dock may not be so familiar, or so benign.

Because they can disrupt entire ecosystems by outcompeting native creatures, invasive species' impacts go beyond the ecological, Chapman said. By compromising commercially valuable species—oysters or crabs, for example—invaders can damage economies.

It's impossible to predict the changes an invasive species may cause—it's far better to try and keep them out in the first place, Chapman said.

(See a rare video of the Japan tsunami.)

Published June 13, 2012

Twisted Character

Photograph courtesy Oregon Department of Fish and Wildlife

"On that dock probably 50 or more species that survived the crossing are not species that we've seen crossing the globe before," Chapman said. "And we've also already identified three real bad characters that were aboard," including wakame seaweed (pictured).

Used in miso soup, wakame is "valuable in Asia," Chapman said. "But you can only eat so many bowls before you're buried in the stuff. It has already been introduced in California, and we are concerned about it spreading north."

The other two known troublemakers on board are the Japanese shore crab, which has already invaded the U.S. East Coast, and the northern Pacific sea star, which has invaded Tasmania—both known to decimate native shellfish populations.

(Related: "Starfish Swarm Devouring Corals in Indonesia.")

Published June 13, 2012

Kill It With Fire

Photograph courtesy Oregon Department of Fish and Wildlife

Workers use torches to sterilize the tsunami-tossed dock on June 7. There was only so much that could be done, though, once the dock had hit the Oregon shore.

"Sixty percent of the dock's surface area was on the bottom when it washed up on the beach, and the [organisms] that were on there were scraped off and washed away," Chapman said. "It's like a spectacular, large, dirty needle that just got stuck into our ecological arm, into our ecosystem."

(See "Japan Tsunami-Debris Cruise Attracts Travelers to Ocean Garbage Patch.")

Published June 13, 2012

On the Grid

Photograph by Lynn Mattes

Though the Japanese dock was teeming with marine life—including algae, seen in close-up—the structure tested negative for radiation from the accident at the Fukushima Daiichi Nuclear Power Plant. (Related photos: "The Nuclear Cleanup Struggle at Fukushima.")

The dock's future remains uncertain. The Oregon Parks and Recreation Department is taking bids on either demolishing the structure or salvaging it and towing it to the nearby Port of Newport. (Read the latest updates on the dock status.)

Though it's by far the largest piece of Japanese tsunami debris seen so far, the dock is not alone.

The Japanese government has estimated that some five million tons of debris were swept away during the tsunami, and about 1.5 million tons have floated to far-off points unknown. (See how NASA is helping to track the debris.)

Published June 13, 2012

Stranger in a Strange Land

Photograph courtesy Oregon Department of Fish and Wildlife

Not all of the species found on the Japanese dock were as foreign as this invasive pink Japanese acorn barnacle. Some are already known to U.S. shores, and others are relatively harmless mid-ocean drifters that make a living attaching themselves to floating objects.

Chapman, one of the first scientists to visit the dock, was surprised by its biological diversity.

"I should have known immediately," he said, "but when I saw this, it took me quite a while to realize what I was seeing—that these algae and mussels and other species were things that I've never known on these shores before."

(Tsunami pictures from National Geographic magazine: "The Calm Before the Wave.")

Published June 13, 2012

"Biological Invasion"

Photograph by Lynn Mattes

Scientists haven't yet identified all the species on the dock—including these reddish anemones. But extensive samples have been collected for future study.

And while the introduction of so many species to the Oregon coast is cause for concern, it also presents a bit of a silver lining.

"This is the most spectacular opportunity to understand biological invasion that's come along maybe in a hundred years," Chapman said. "Here is a drifting object that's gone across the entire ocean, and we know exactly where it came from in Japan to a matter of feet.

"Now we can examine what survived and what did not in a very scientific way, and we'll learn a lot about a biological invasion."

(See "Tsunami Waves Hit U.S.—Some Damage in Hawaii, California.")

Published June 13, 2012

Name Tag

Photograph courtesy Oregon Department of Fish and Wildlife

The Japanese consulate in Portland, Oregon, used this plate to identify the dock's original location as Japan's Misawa fishing port.

While tsunamis are natural occurrences and drifting objects regularly carry species coast to coast, "nothing like this has ever drifted across the ocean" before, according to Chapman.

Published June 13, 2012

Close to Home

Photograph courtesy Dylan McCord, U.S. Navy

A house adrift off Japan is a reminder of the earthquake and tsunami that claimed some 20,000 lives on March 11, 2011—two days before this picture was taken.

"Always on our minds is the horrific tragedy in Japan," Chapman said of his work on the dock.

"If we could only undo it, we would. ... I just hope that we are always being respectful, because in all ways we feel for them, and our problems in this are tiny compared to theirs."

Published June 13, 2012

Next: Japan Tsunami: 20 Unforgettable Pictures >>

Photograph by David Guttenfelder, AP

Published June 13, 2012