March 11 marks the one-year anniversary of the tragic Tohoku earthquake and tsunami in Japan. Because millions of tons of debris flooded into the sea from this catastrophic event, it’s understandable that people are concerned about tsunami-related material washing onto Southern California beaches. Here are a few answers to common questions Heal the Bay hears about the debris.

How much trash did the tsunami drive into the ocean?

Some reports have claimed that 20 to 25 million tons of debris washed into the ocean during the Japanese tsunami last year. However, there is no confirmed estimate of how much debris actually went into the water. National Oceanic and Atmospheric Administration scientists and other experts believe that much of the tsunami debris sank off Japan’s coast.

Will tsunami-related debris hit Southern California shores?

Beachgoers may notice a gradual increase in debris near shore and on Southern California beaches over the next few years, but it will likely be difficult to differentiate tsunami-debris from trash that normally flows from land-based sources and washes up onto our beaches. Satellites tracking the initial floating debris field find it to have dissipated and dispersed. Winds and ocean currents scatter items in patterns that are difficult to predict. Scientists believe some of the debris may eventually reach Southern California. Tracking expeditions are underway to scout for tsunami-related debris by groups like 5 Gyres, which will be sharing their findings with NOAA, other scientists and the public.

When do we expect to first see it?

Wind, waves and ocean currents make it difficult to predict an exact date and location for tsunami debris arrival on our shores. Beachgoers in Alaska and Washington have already reported a few incidents of debris, such as buoys, reaching shorelines that may have come from the tsunami. However, scientists have not confirmed that these items are tsunami-related. Buoys and floats from Asia often wash up on our shores, so it’s very difficult to identify the exact source of these items. Not every item found on the beach with Asian writing is from the Japan tsunami. Marine debris in Southern California is an everyday problem, stemming from urban runoff and ocean sources throughout the Pacific.

Is the tsunami debris radioactive?

It’s highly unlikely that any tsunami-related debris is radioactive, according to scientific consensus. It’s improbable that most of the debris came into contact with radioactivity associated with leaks at crippled nuclear power plants in Japan. Debris from the tsunami came from a large stretch of coastal Japan, while the leak from the damaged Fukushima reactor occurred in one location. Additionally, there was no likely source of debris exposure to radiation. When the radioactive leak developed, the bulk of the debris had already flowed offshore. Furthermore, results from monitoring conducted on debris found at sea from the Fukushima region in September showed no radioactivity.

Is it possible that human remains may wash ashore here?

There is little chance this will happen.

What should someone do if they think they see tsunami debris on Southern California shores?

If you see any waste material you think may be related to the tsunami, we recommend you take a photo and report it to Heal the Bay. If you see large volumes of debris or items that clearly came from Japan, please report them to NOAA via e-mail:

What if it looks dangerous or harmful to health?

Heal the Bay encourages anyone that sees strange or potentially harmful items on the beach to notify your local emergency agency. No one should touch or try to remove such items. Heal the Bay cares deeply about our coast and volunteers, and we will continue to follow the news and scientific updates about the tsunami debris to make sure that our programs and volunteers have the most updated information possible.

What can I do to help?

Tsunami-related trash may be in the news now, but marine debris is a persistent problem in Southern California every year, whether it comes from overseas or from inland sources. Heal the Bay conducts regular clean-ups on beaches throughout Los Angeles County, and we invite anyone to join us. As we continue to clean up Southern California’s beaches, we will be scouting for any potential tsunami related debris. You can join us at

For more information, please call Heal the Bay at (310) 451-1500.

Sikich is Heal the Bay’s coastal resources director.

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