Rough seas and a dangerously swollen stream are keeping tsunami debris experts from reaching a dock that washed ashore on a remote beach in Washington. It's likely that the large dock is debris from the March 2011 tsunami in Japan.

A spokesman for the Washington state Marine Debris Task Force says state and federal representatives got within 200 yards of the dock Thursday but the crew couldn't cross a normally passable creek that was running high and fast.

Team members plan to try again Friday if weather permits. They hope to verify the dock's origin, measure it and inspect it for invasive species.

The Coast Guard spotted the dock Tuesday on a wilderness beach in Olympic National Park. The area can only be accessed by primitive trails across rough terrain.

Officials say the dock appears to be similar to a Japanese dock that washed ashore last June in Newport, Ore. That debris was cut up and removed.

After a large dock from the Japanese tsunami washed ashore last June on a Newport beach, volunteers scraped off 2 tons of seaweed and creatures that had hitched a ride across the Pacific.

They were buried above the high-water line, and the dock was scorched with torches to sterilize it.

Officials are concerned about non-native species invading Oregon waters.

A manager of marine resources for Oregon Department of Fish and Wildlife, Caren Braby, says the dock carried four species — a seaweed, a sea star, a mussel and a shore crab — that are native to Japan and have established themselves as invasive species elsewhere.

She says officials won't know for a couple years whether any of them escaped to get a foothold in Oregon.

Northwest Lending Group