NEWPORT, Ore. When debris from the 2011 earthquake and tsunami in Japan began making its way toward the West Coast of the United States, there were fears of possible radiation and chemical contamination as well as costly cleanup.
But a floating dock that unexpectedly washed ashore in Newport this week and has been traced back to the Japanese disaster has brought with it a completely different threat invasive species.
Scientists at Oregon State University's Hatfield Marine Science Center said the cement float contains about 13 pounds of organisms per square foot, and an estimated 100 tons overall. Already they have gathered samples of 4-6 species of barnacles, starfish, urchins, anemones, amphipods, worms, mussels, limpets, snails, solitary tunicates and algae and there are dozens of species overall.
"This float is an island unlike any transoceanic debris we have ever seen," said John Chapman, an OSU marine invasive species specialist. "Drifting boats lack such dense fouling communities, and few of these species are already on this coast. Nearly all of the species we've looked at were established on the float before the tsunami; few came after it was at sea."
Chapman said it was "mind-boggling" how these organisms survived their trek across the Pacific Ocean. The low productivity of open-ocean waters should have starved at least some of the organisms, he said.
"It is as if the float drifted over here by hugging the coasts, but that is of course impossible," Chapman said. "Life on the open ocean, while drifting, may be more gentle for these organisms than we initially suspected. Invertebrates can survive for months without food and the most abundant algae species may not have had the normal compliment of herbivores. Still, it is surprising."
Jessica Miller, an Oregon State University marine ecologist, said that a brown algae (Undaria pinnatifida), commonly called wakame, was present across most of the dock
|Contact: John Chapman|
Oregon State University