State workers removed dozens of non-native plant and animal species on a dock that washed ashore in a remote section of the Olympic National Park and is believed to have drifted across the Pacific Ocean after the March 2011 Japanese tsunami.
Lab results have identified 30 to 50 species on the dock that are native to Japan but not found in the United States, including types of algae, seaweed, mussels and barnacles.
A team of six traversed more than three miles of old logging roads, climbed over downed logs and forded a creek last week to get to the 65-foot dock, which is aground on a stretch of beach between LaPush and the mouth of the Hoh River.
The team scraped more than 400 pounds of organic material from the dock and removed its large plastic bumpers, estimated to weigh more than 100 pounds each, to examine them for invasive species. The team washed the bumpers and the dock with a diluted bleach solution to decontaminate them.
There is Japanese writing on some of the dock’s holds, according to the Washington State Department of Ecology, but the government of Japan has not yet been able to positively identify the dock from photos.
The dock was first spotted by the crew of the fishing vessel Lady Nancy in mid-December adrift about 16 nautical miles northwest of Grays Harbor, on the Washington coast. The U.S. Coast Guard then launched an extensive helicopter search to locate the dock, while the National Oceanic and Atmospheric Administration worked to determine its trajectory based on where it was spotted.
The Coast Guard located the dock on Dec. 18, but a dangerously swollen stream and rough, high seas made reaching it difficult. A ground crew made two attempts to reach the dock, finally accessing it on Friday, Dec. 21. Working quickly during the month’s last daytime low tide, the team measured and inspected the dock, collected samples of the marine organisms clinging to it and placed a tracking beacon on it.
State and federal agencies are making plans to remove the structure from the park.
“We’re extremely grateful for the support and expertise of our federal and Washington state partners,” Olympic National Park Superintendent Sarah Creachbaum said in a statement.
“As we move forward as a team, our first concerns will be safety in this rugged stretch of coastline and assessment and containment of any invasive species.”