Tsunami Marine Debris

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Tsunami Marine Debris (English)
津波による海洋ゴミ (日本語)

In March 2011 Japan was struck by a large earthquake and resultant tsunami that killed thousands of people, resulted in billions of dollars in property damage and caused the release of radioactivity from several nuclear power plants. The tsunami swept a tremendous amount of debris into the ocean, including buildings, boats, automobiles and numerous smaller items.

Prevailing ocean currents are carrying the “tsunami debris field” eastward across the Pacific Ocean towards the West Coast of the United States and Canada. As time passes, the debris has dispersed and is no longer visible from satellites as a concentrated debris field. Some of the debris is predicted to be reach the northwestern Hawaiian Islands as early as this (2011-2012) winter, approach the West Coast of the United States in 2013, and circle back to the main Hawaiian Islands in 2014 to 2016. Some very light floatable objects may travel faster. In fact, a float from Japan was found on the beaches of Washington in December 2011. The transport time of the float was no doubt speeded up by prevailing winds, while heavier items will move more slowly.

Computer Modeling of Tsunami Debris. Source:J. Churnside (NOAA OAR)

Transport of the debris field items is not necessarily a straight path west-to-east path. The North Pacific Gyre will capture some of the debris, where it could slowly spin in a clockwise direction for many years. The Hawaiian Islands will be impacted, as well as other islands in the northern Pacific Ocean.

Since the debris consists of a wide variety of items of different sizes and materials of construction (wood, metal, glass, plastic), the travel times and trajectories will vary and are therefore difficult to predict. Some materials will sink, some will decompose, and others will make it to our beaches.

NOAA has compiled a lot of useful information regarding the tsunami marine debris, with answers to frequently asked questions. Watch this short video, which also appears on the NOAA website.

Perhaps one of the most common concerns is whether the debris might be radioactive. Here is NOAA’s response:

“There is consensus among scientists that this is highly unlikely, for several reasons:

• First, the tsunami created debris over a large stretch of coastal Japan, while the leak from the damaged Fukushima reactor occurred in one place. Therefore, the vast majority of the debris was many miles away from the reactor, precluding any contact with the radioactive leak.
• Second, the leak of contaminated water from the reactor into the sea started days to weeks after the debris was washed out to sea. By the time the radioactive water leak developed, the debris was already in the ocean, miles away from the reactor, and moving farther offshore by currents and wind. Exposure to contaminated water, which also moves by currents, was unlikely to occur.
• Finally, vessels coming into the United States from Japan were monitored for radiation, and readings were below the level of concern. In the one instance where debris from the Fukushima region was found – a small boat picked up by the research vessel STS Pallada – it was tested for radiation and the levels were normal.”

Surfrider Foundation chapters in Hawaii and on the West Coast have been closely following the release of information concerning the tsunami debris. Our Kauai Chapter helped organize a one-day seminar which brought together experts, our Olympic Peninsula Chapter in Washington hosted a meeting with a prominent oceanographer (where it was revealed that a float from Japan had reached our shores), and our Oregon Chapters have partnered with another local group and Oregon Sea Grant on a NOAA grant application to coordinate a statewide effort for cleanup response and monitoring. We’ve also been following the NOAA webinars and we'll be taking notes from the experiences in Hawaii given that they may get hit with the first wave of debris.

Information on significant marine debris sightings in the North Pacific Ocean and on the coast is greatly needed and can be reported to the NOAA Marine Debris Program at DisasterDebris@noaa.gov.

If you who wish to contribute to the collection of baseline marine debris information, consider downloading and using the Marine Debris Tracker smartphone application to record, visualize, and share data.