The state Marine Debris Task Force says it was identified by the Japanese government through photos that showed a fender serial number. The dock came from the Aomori Prefecture and is similar to the dock that washed ashore last summer at Newport, Ore., also from the tsunami.
The Coast Guard spotted the dock Dec. 18 on a beach near Forks. It's within a wilderness portion of Olympic National Park and also within the Olympic Coast National Marine Sanctuary and will be removed.
A crew has already scraped off 400 pounds of marine plants and animals in an attempt to prevent any invasive species from taking hold.