Debris from 2011 Tsunami in Japan Brings Alien Species to U.S. Shores

A 66-foot dock carried more than 1.5 tons of nonindigenous species to the shores of Oregon.

The magnitude 9.0 Tohoku earthquake in Japan last year and resulting tsunami has brought a variety of invasive species to the shores of the West Coast of the United States. These species, hitching rides on tsunami debris, such as floating docks, motorcycles and other remnants of the March 11, 2011, earthquake and tsunami, have begun arriving on the shores of the West Coast after 15 months at sea. The Associated Press is reporting that a 66-foot-long dock that washed onto an Oregon beach carried more than 1.5 tons of marine species, including Asian crabs, sea stars, algae, urchins, barnacles, snails, seaweed and other organisms. One species of seaweed found on the dock, called wakame, is a nuisance species found around the world but not in Oregon where the dock landed.

John Chapman, an Oregon State University marine invasive species specialist, said, “This float is an island unlike any transoceanic debris we have ever seen. 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 he was surprised that the creatures survived the journey across the ocean. The low productivity of open ocean waters should have starved at least some of the organisms that they scraped off the dock.

Invasive species can wreak havoc wherever they land. Zebra mussels (Dreissena polymorpha) and the sea lamprey (Petromyzon marinus) are now established in the Great Lakes, with the lamprey responsible for killing off the native lake trout populations. The zebra mussel clogs drains and sewer systems. The quagga mussel (Dreissena bugensis), a close relative of the zebra mussel, has made its way from the Ukraine to the United States. Recreational boaters in California have to abide by state regulations when launching their boats into certain lakes to minimize the spread of this mussel. Like the zebra mussel, quagga mussels consume large amounts of plantkon, clog drains and other water systems, and they take in large amounts of pollutants that in turn harms the wildlife that eats them. The red lionfish (Pterois volitans), a native of the Indo Pacific, has become well-established on the Atlantic coast, so much so that the Florida Keys has been holding lionfish derbies  for the past several years in an effort to control their populations. 


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Fish · Saltwater Fish