Wednesday, June 27, 2012

Invasive Species from Fukushima Tsunami Washing up on U.S. Shores


Japan's tsunami-caused nuclear disaster at the Fukushima energy complex in March 2011, in which three atomic reactors were heavily damaged, continues to wreak havoc on ecosystems - in the U.S.

The latest danger emanating from the Fukushima complex to hit our shores came not in the form of irradiated tuna, but in the form of a boxcar-sized piece of floating dock which washed ashore along a sandy Oregon beach earlier this month. The find initially excited some beachcombers, reports said, but scientists quickly began to worry that such debris was quickly becoming a whole new way to transport invasive species - crabs, seaweed and other marine organisms - to U.S. waters, further harming West Coast marine environments, The Associated Press reported.

Worse, scientists and marine biologists suspect more species could be hitching a ride to our shores as more tsunami debris arrives in the coming months.

"We know extinctions occur with invasions," John Chapman, assistant professor of fisheries and invasive species at Oregon State University's Hatfield Marine Science Center, told AP. "This is like arrows shot into the dark. Some of them could hit a mark."

Mitten crabs, spartina, shellfish all cause problems here - though they came from far away

Indeed. While international trade has meant that marine invasion to the West Coast has been occurring since the late 1860s, the global economy has greatly accelerated the process. So much so that now, there are areas like San Francisco Bay which amount to a "global zoo" of invasive species, where as many as 500 plants and animals from waters afar have established in U.S. waters.

The species can attach themselves to the hulls of cargo ships and the water some vessels take on as ballast, but have also come from home aquariums that have been emptied into bays.

Not only have the species upset marine ecosystems, but there are staggering costs associated with the phenomenon as well, in tens of billions of dollars.

"Mitten crabs from China eat baby Dungeness crabs that are one of the region's top commercial fisheries. Spartina, a ropey seaweed from Europe, chokes commercial oyster beds. Shellfish plug the cooling water intakes of power plants. Kelps and tiny shrimp-like creatures change the food web that fish, marine mammals and even humans depend on," the AP reported.

If anything, the Fukushima disaster will only make matters worse, since the problem has been growing for years. A 2004 study published by the scientific journal Ecological Economic, for example, estimated then that some 400 threatened and endangered species in the U.S. were facing wipe-out due to invasive species.

That said, scientists admit it's too early to tell how badly Japan's tsunami debris will worsen the situation already here in the U.S.

"It may only introduce one thing," Andrew Cohen, director of the Center for Research on Aquatic Bioinvasions in Richmond, Calif., said. "But if that thing turns out to be a big problem, we would rather it not happen. There could be an economic impact, an ecological impact, or even a human health impact."

Johnny Clamseed

Reports said the dock that washed ashore in Oregon came from a fishing port located on Japan's northern tip. It was strewn with a ton-and-a-half of mussels, seaweed, barnacles and starfish. AP reported that volunteers scraped it clean then buried it above the high water line and sterilized the rest with torches.

Some experts said, however, that despite the cleaning, there was no way to tell yet whether the scrap had released spores, larvae or anything else that could spawn and grow somewhere along the coast.

"That's the 'Johnny Clamseed' approach," James Carlton, professor of marine sciences at Williams College, said, a reference to John Chapman, better known as Johnny Appleseed, who introduced apple trees to parts of Pennsylvania, Ohio, Illinois and Indiana in the 19th century. "While that is theoretical, we don't actually know if that kind of thing happens."

Yet, scientists say they do know that the bigger the debris, the more likely it is bringing something along for the ride.

More debris continues to wash ashore along U.S. beaches - so much so that state officials are beginning to make appeals to Washington for help. This week, Washington state Gov. Chris Gregoire announced plans for her state to begin clean-up efforts but said federal help would be needed.

"We don't have the resources at the state level to do what we're going to have to do here," she said.


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