Mystic scientist analyzing cross-sea species ‘rafting’

Mystic scientist analyzing cross-sea species ‘rafting’

The Westerly Sun

NARRAGANSETT — Stored in a laboratory in Mystic are hundreds of species that traveled across the sea all the way from Japan to North America by hitching a ride on debris from the catastrophic tsunami of 2011.

James T. Carlton, professor of marine sciences emeritus at the Maritime Studies Program of Williams College and Mystic Seaport, and an expert on global marine bioinvasions, has collected more than 300 organisms from Japan that came ashore in Oregon, Washington and British Columbia.

Carlton discussed his work on Thursday at the University of Rhode Island’s Graduate School of Oceanography as part of the Coastal State series, sponsored by Rhode Island Sea Grant.

On March 11, 2011, a magnitude 9.0 undersea earthquake, the most powerful ever to hit Japan, produced tsunami waves of up to 133 feet. Nearly 16,000 people died, and countless structures, including buildings, docks and ships, were washed out to sea.

Carlton described the path of the tsunami as it traveled across the Pacific Ocean.

“At about 3 in the afternoon, the earthquake hit in Japan. It traveled across the Pacific, came ashore in the Pacific Northwest on Friday, March 11, in the morning, because of the dateline, the same day, washed all the way through the Pacific, took out the marine laboratory in the Galapagos Islands, the Darwin Research Station, and eventually the waves washed ashore in the Antarctic,” he said.

Organisms aboard

In a process known as ocean rafting, displaced organisms traveled nearly 4,400 miles across the Pacific, surviving on debris like tree trunks and root masses and also living, and even reproducing, on drifting docks and boats. The debris began washing up on the Pacific coasts about a year after the earthquake, and Carlton said what made the event unusual was that the plants and animals were still alive.

“There are no records in historical literature, scientific literature or management policy literature of anything rafting in from Japan or China or Russia and landing, alive, on the Pacific coast of North America,” he said.

Inside, as well as on the surface of a dock that washed ashore in Oregon, investigators found more than 125 species.

“What was interesting, was that many of these species were already poster children of invasives around the world,” Carlton said. As scientists rushed to catalog the arriving debris and its organisms, officials would sometimes get there first and clean the object to rid it of possibly invasive animals and plants, leaving scientists with nothing to study. Well-intentioned beach cleanups also removed debris before it could be identified.

“Beach cleanups — a very positive thing — large beach cleanups that took a fair amount of debris before we could ever see it,” he said.

Among the Japanese crabs, barnacles, flatworms, sea stars and the occasional fish were mussels that contained a tiny species of hydroid, invertebrates that can cause shellfish mortality. Carlton said no invasions directly linked to the tsunami have been reported, but it could take years for invasive organisms to become established, so scientists were closely monitoring coastal waters.

The tsunami debris affected the Pacific Northwest, but other natural disasters such as hurricanes, which are frequent on the East Coast, also transport debris. In 2012, Superstorm Sandy left behind vast amounts of debris, which in addition to posing a navigational hazard, damaged sensitive coastal ecosystems such as salt marshes. Carlton said marine debris is a significant global issue that should be more extensively studied because of the organisms that could be living on it.

“The biology of the debris is one thing we haven’t been studying,” he said. “What’s on the debris could tell us a lot more about its history, its origin and its potential to move species, which is one of the invasive species issues.”



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