Log Lunch: Invasive Species after the 2011 Tsunami in Japan

A dock from Misawa, Japan, washed up on the shores of Olympic National Park last December, carrying 400 pounds of Japanese plant and animal matter.

Williams Mystic Professor of Biology James Carlton discussed the dangers posed by debris from the March 2011 tsunami in Japan on the western coast of the U.S. during a Log Lunch on Friday, April 12.

After thirteen-foot waves hit coastal Japan in the wake of the March 11, 2011 earthquake, much debris was washed off of the highly developed coasts and was swept out to sea. Since then, this flotsam has been appearing on land across the Pacific Islands and the west coast of the United States. Hundreds of invasive species have accompanied the debris. For example, one small boat that showed up in Oregon held more than 60 species of fish and crustaceans within a small tidal pool that had formed in the boat’s bottom.

More problematic have been the four sixty-foot-long concrete docks that were washed away from Misawa, Japan. Japanese officials sighted the first dock floating by a Japanese island only two weeks after the event. In June 2012, more than a year after the tsunami, the second dock came ashore in Newport, Oregon, attached to which the Coast Guard found hundreds of pounds of plant and animal matter. Volunteers spent days scraping the potential invasive species from the dock and sterilizing the area. Particularly threatening was a certain kind of algae that had already taken root in southern California but had not yet made it to the Oregon coast. This algae and other invasive species threaten the biodiversity of the region and push native species to extinction.

Another dock washed up onto the Washington coast last December.  A team of four biologists, including Carlton, immediately tracked down the dock and identified it as one of the Misawa docks. During one week in March 2013, volunteers worked to remove the dock, which had landed in a protected wildlife area of Olympic National Park. They found more than thirty different species on the dock, and 400 pounds of plant and animal matter.

The costs were paid for by the Japanese government to the National Oceanographic and Atmospheric Administration’s Marine Debris Program, which was in charge of removing the docks.