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Water | Environment

Tsunami Dock Species Under the Microscope

The Japanese dock that washed ashore in Oregon carried more than a few invasive species. Scientists have found enough living cargo to keep them busy for decades.

Experts at Oregon State University’s Hatfield Marine Science Center have fifty-some species stored in a subzero freezer. OSU marine ecologist Jessica Miller said they have identified some species and shipped others to scientists around the country and in Canada.

“Sea squirts or tunicates, a group called ascidians, we sent some samples out to an expert, and then Gayle Hansen, here at OSU who works with a Japanese colleague, she’s been sorting her way through the algal species,” she said.

Miller thinks an invasive brown algae might try to settle in the Pacific Northwest.

“The Undaria would probably be the one where you would might estimate would have the highest chance of causing some problems in this region, because there were lots of individuals on the outside of the dock and they were, according to experts, were releasing spores,” Miller said.

wakame (Undaria pinnatifida) (1 of 1)

Undaria pinnatifida. Credit: Hatfield Marine Science Center

That particular algae already has invaded some California waters, said Rick Boatner, Invasive Species Wildlife Integrity Coordinator for Oregon’s Department of Fish and Wildlife.

Undaria grows fast and kill off native kelp by blocking their sunlight, he said. Losing the native kelp would be devastating to lots of fish species who use it as their spawning grounds.

One surprise was what was inside the dock. When the researchers pried off a panel, they found the invasive starfish, Miller said. None were found on the outside.

Star Fish Tsunami Dock (1 of 1)

_North Pacific seastar. Credit: Hatfield Marine Science Center

Identifying what was onboard the dock is just the first step for scientists. They also want to know what might happen next.

“For the species that had to have come from the coastal waters of Japan and survived the whole 14-month journey over here if we could learn more about their growth rates and maybe what water masses they were in, we can get a better handle which species are most likely to invade and better understand the dispersal possibilities,” Miller said.

The Japanese dock had been in the water since 2008. That gives scientists some clues about how old some of the species might have been before the tsunami sent them across the Pacific.

It is that journey that intrigues Miller. She has researched the migration, dispersal and movement of fishes.

“I use the ear bone, which is a calcium-carbonate structure in their head where you can track their moving and migration with the structure and chemical composition of that and you can do similar work with shells,” she said.

She wants to apply that science to the mussels and other shelled species that latched onto the dock in Japan.

Fix Your Coordinates

mapcompass1 md5-78bf33ace23178c065be78831b338240 Officials have this advice for beachcombers who may come across debris that contains living organisms: - Take a picture and send it to - Dispose of them in a garbage can off the beach on in a landfill. - DO NOT put the debris into the ocean or any other water source. For more information [visit Oregon’s Department of Fish and Wildlife]( “”).

Shells lay down growth rings that will that will help scientists look for patterns, she said.

The more they know about each species, the easier it will be to determine which ones lived on the dock in Japan and which ones hitched a ride somewhere in the open ocean.

Other scientists likely will be monitoring the waters to the north and south of the dock’s landing point, watching for species that may be trying to establish themselves here.

Miller said that another OSU scientist and invasive species specialist, John Chapman, already has done an assessment of some of those areas. That work will provide a baseline for the species that lived there before the dock arrived.

No one knows which species may have disembarked along the coasts of Oregon or Washington. And no one know what was living on the bottom of the dock because it was scraped clean as it washed ashore.

The action of the dock in the surf probably was a lot like sandblasting, Miller said.

Screen shot 2012-06-19 at 3.30.24 PM


Credit: Hatfield Marine Science Center

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