Since I first wrote about the dock carrying invasive plants and animals washing up on an Oregon beach in my early June blog post, “First wave of tsunami debris brings dock loaded with invasive species to the US West Coast“, a lot has happened! This is what I’ve learned so far…
How do you get rid of a 47 ton dock?
In March 2011, a terrible tsunami washed away a shipping dock from Japan’s coast. It took about 15 months for the floating dock to travel across the vast Pacific Ocean and wash up on an Oregon beach in June 2012.
After workers and volunteers from the Oregon Parks and Recreation Department scrambled to remove the invasive plants and animals that they could find on the dock, they had to figure out how to dispose of the dock. This presented a challenging problem!
The Oregon Parks and Recreation Department looked at three options:
- Demolishing it in place
- Towing it from the beach to the Port of Newport
- Or a bit of both
The large amount of styrofoam in the dock, needed to keep it afloat, made demolishing it a problem, since I imagine that pieces can easily fly around and float away as the dock is being dismantled. This means taking it apart was expected to be more expensive and time consuming.
The department decided to award the removal contract to Ballard Diving and Salvage with a plan to dismantle the dock on shore and remove it in pieces by land. This helps keep the debris and any remaining creatures on the dock from washing away in the water.
The company cut the dock into sections with a wire saw and used a crane to lift the dock sections onto trucks. The trucks took the sections to Portland for final dismantling and recycling.
Were invasive species still hiding on the dismantled dock?
Although the Oregon Fish and Wildlife Department removed and buried a lot of plants and animals from the dock (more than two tons!), they couldn’t be sure that they removed everything, such as algae and smaller animals that might be hiding inside portions of the dock.
Invasive species can cause millions of dollars in economic and ecological damage, so the department wanted to handle the dock and the invasive plants and animals with extreme care.
Among other creatures, department workers found and removed two of the world’s 100 worst invasive species from the dock:
- Northern Pacific Sea Star (Asterias amurensis)
- Wakame, a marine alga (Undaria pinnatifid)
They didn’t want to try to reuse the dock because of the same concerns that they have about moving it through the water. So, they dismantled it, and they said that they would save part of it too for a museum.
And yes, when department biologists inspected the bottom and insides of the dock, they found more invasive species, including pink Japanese acorn barnacles…
…but thankfully, they were no longer alive.
What happens if more debris wash up on shore?
The department also talked about what to do if people find more debris on our West Coast beaches:
- Litter, like plastic bottles or cans, that people can dispose of or recycle
- Derelict vessels or other large debris that the U.S. Coast Guard can help remove
- Mementos or possessions that the department can help return back to Japan
- Hazardous materials, such as oil or chemicals, that the U.S. Coast Guard’s National Response center can also help remove
- March 11, 2011 – Tsunami strikes Japan and carries off the dock
- June 5, 2012 – Dock carrying invasive species washes up on an Oregon beach
- June 7-8, 2012 – Oregon Parks and Recreation Department cleans over two tons of invasive plants and animals from the dock
- August 4, 2012 – Company hired by the Oregon Parks and Recreation Department dismantles the dock on the beach and carries it away overland for disposal
Learn more about the dock and the terrible tsunami
- Oregon Parks and Recreation Department site about the tsunami dock at Agate Beach
- Japan’s earthquake and tsunami: How they happened