For additional information, see Oregon State University’s Press Release, 6-7-2012
Tens of thousands of lives were lost and thousands injured as a result of the devastating tsunami that was generated as a result of a magnitude 9.0 undersea earthquake off the coast of Japan on 11 March 2011. Additionally, there was tremendous damage to infrastructure, including nuclear power plants. There has been growing concern in regard to the wave of tsunami debris that has been travelling with ocean currents since March 2011. The Japanese government estimated that approximately 5 million tons of debris was swept into the ocean; of this, the majority (~70%) is thought to have sunk relatively close to shore, resulting in 1.5 to 2 million tons remaining floating in the ocean and potentially inbound to North America. Modeling efforts indicate that buoyant objects with greater surface area above the water line would reach the west coast of the US as early as the winter of 2011-2012.
A large floating dock (~66’ x 19’ x 7’) that was ripped from its pilings in Misawa, Japan by the tsunami arrived on the shores of Newport in central Oregon late on June 4 or very early on June 5. Scientists from the OSU Hatfield Marine Science Center, including Dr. Jessica Miller, Dr. John Chapman, and Dr. Gayle Hansen, inspected the dock on June 5 and were surprised by the diversity and magnitude of marine life present on all sides of the structure. Although there were species commonly observed on oceanic floating debris, such as pelagic barnacles (Lepassp.), there appeared to be an intact subtidal community of Asian species present on the majority of the structure.
On June 6, scientists systematically sample the structure, taking many digital images and collecting animals and plants. Initial inspection indicated that potentially aggressive invasive species were present, including the European blue mussel, Mytilus galloprovincialis (an invader of Japan itself) the Asian brown seaweed Undaria pinnatifida, the Asian shore crab Hemigrapsus sanguineus and the Japanese seastarAsterias amurensis (which was found only inside the dock within the hold that had taken on water through a crack in concrete).
Given the presence of these species, and of others of unknown risk, Oregon Department of Fish and Wildlife (led by Steve Rumrill and Rick Boatner) coordinated the effort to scrape and “torch” the entire dock to remove ~ 2 tons of attached fouling organisms that were then buried by Oregon State Parks at a depth of ~8’ at high beach elevations. Analyses are ongoing, and data resulting from investigations conducted at the OSU Hatfield Marine Science Center will be reported here as they become available.