About five million tons: That’s how much debris the Japanese Ministry of the Environment estimates was swept into the ocean during the powerful earthquake and subsequent tsunami that occurred in Japan in March of 2011.
An estimated 70 percent sank offshore and another 1.5 million were carried into open water by ocean currents and wind.
While this is the latest high-profile case of debris in the ocean, it represents just a fraction of the overall ocean trash problem.
A tsunami's worth of ocean trash is created every year simply by the things we buy, use and throw away.
The tsunami debris will likely add to the growing problem of ocean trash on the west coast of the United States and the accumulation of trash in the Pacific Gyre.
Ocean Conservancy has been involved from the start:
A number of questions have surfaced about the tsunami debris. Ocean Conservancy marine debris scientist Nick Mallos provides answers.
When will tsunami debris reach the west coast?
Researchers are working on projections for where and when the tsunami debris could wash ashore, using computer models and reports from ships and some debris has already reach the US shores. But here is a rough timeline based on computer models:
Early 2013: Canada and the U.S. West Coast—especially Washington State—could see larger amounts of debris coming ashore.
2015-25: Debris still at sea could be carried into the North Pacific Gyre.
Is the tsunami debris radioactive?
Experts agree that contamination is improbable. Debris tested so far has not been positive for radiation.
Is tsunami debris a danger to wildlife?
Like all ocean trash, the tsunami debris could have significant impacts on wildlife that eats it or becomes entangled. Fishing gear lost during the tsunami could inadvertently catch seabirds and migratory species that use North Pacific waters to forage, breed and migrate.
Why are scientists looking at invasive species?
When a species hitchhikes on trash to new territroy, trouble can ensue. Because there are no natural predators in its new habitat, the alien species' population can explode and threaten the balance of the entire ecosystem.
Tsunami debris that was originally submerged in the marine environment (e.g. docks, harbor infrastructure, boats, etc.) pose a higher risk of containing coastal aquatic invasive species and therefore a greater threat to the West Coast’s coastal waters than tsunami debris of terrestrial origins (e.g. house, soccer ball, fridge, etc.).
What if I spot tsunami debris?
Marine debris items or significant accumulations potentially related to the tsunami can be reported to DisasterDebris@noaa.gov with as much information as possible (location, date and time found, photos and descriptions). Not all debris found on U.S. shorelines is from Japan or the tsunami, so please use discretion.
While oceanographers are monitoring the Japanese tsunami debris, there are many questions and misconceptions about it that need to be addressed.
If you are a beach-goer on the West Coast, you are increasingly likely to find tsunami debris. Here are some basic guidelines on what to do.