Fukushima Fallout: Japan's Radiated Ocean

May 18, 2011· 2 MIN READ
A six-time grantee of the National Geographic Expeditions Council, Jon writes about all things ocean.
A steel floating structure used to store contaminated water heads to the tsunami-crippled Daiichi nuclear power plant in Fukushima. (Photo: Ho New / Reuters)

As the world’s attention rushes from one natural disaster to the next—tornadoes, 100-year floods, earthquakes, and tsunamis—let’s not lose track of all the radiated water that continues to leak into the ocean along the Japanese coast.

While natural disasters are bad by definition, it’s the continued leaking of the Fukushima nuclear plant that may have the most long-lasting environmental impact due to the partial meltdowns, hydrogen explosions, and fires that released unmeasured amounts of radioactive contaminant into air and water.

The plant’s operator, TEPCO, initially dumped 11,500 tons of highly contaminated water on land, which quickly made its way to the ocean. In just the first six days of the spill, which began on April 1, more than 520,000 tons of high-level radioactive water is believed to have reached the sea. That’s 20,000 times the annual allowable limit.

Efforts to cool the reactors with seawater and fresh water continue to poison the ocean more than six weeks after the earthquake—as does fallout, precipitation runoff, and newfound leaks.

At this point no one knows exactly how much contaminated water has been dumped or how truly degradading the spill will be in either the short or long-term.

In separate reports issued this week, Greenpeace and the Japanese government say that samples collected near the plant have shown elevated levels of radiation. Both suggest “containment” is next to impossible.

According to Greenpeace, 10 of 22 seaweed samples collected showed levels five times higher than the standard set for food in Japan. "Radioactive contamination is accumulating in the marine ecosystem that provides Japan with a quarter of its seafood, yet the authorities are still doing very little to protect public health," Greenpeace radiation expert Ike Teuling said in a statement. So far radiation has only been found in one fish species, the Japanese sand lance.

Any such statistics must be worrying to Japanese citizens, for whom seaweed is a dietary staple.

The government’s report was based on studying the radiation levels of garbage, which at one point after the spill spiked to 85 times the allowable levels of radioactive Iodine-131.

Why is the garbage so laced? The government thinks it’s related to rain carrying radiated water into gutters, storm sewers, and dumps.

Oceanographers from the Woods Hole Oceanographic Institute are on the scene in Japan and suggest the groundwater around Fukushima and sediments in the seafloor nearby “will likely be contaminated for decades.” At this point the long-term impact on marine life, fish, and other marine animals can only be guessed.

One of those guesses suggests that the radiated water will only impact the coast of Japan; Woods Hole is readying a research ship to begin observing there.

The leak of contaminated water offers researchers a unique opportunity to test both currents and the longevity and dilutability of a variety of radioactive isotopes. Several types of long-living isotopes will be tracked as they move across the Pacific Ocean (Technetium-99, for example, which is thought to have a half life of 210,000 years and Iodine-29, which has a half-life of 14 million years).

The general current sweeps west from Japan across the Pacific towards the west coast of the U.S.; it’s expected the contaminated water will reach Hawaii in about a year and California in two to three years. By that time it should be “significantly” diluted.

As the growth of nuclear energy continues to expand around the globe during the twenty first century—and as inevitable accidents continue -- governments will most likely get better at assessing and tracking radioactive contamination...just as they did pesticide pollution during the 20th century.

jon_bowermasterA six-time grantee of the National Geographic Expeditions Council, Jon Bowermaster has spent the past two decades circling the world’s ocean, studying both its health and the lives of the people who depend on it. He is the author of 11 books (his most recent, OCEANS, Threats to Our Seas and What You Can Do to Turn the Tide, was published by Participant Media) and producer of a dozen documentary films. His blog—Notes From Sea Level—reports daily on issues impacting the ocean and us. Follow Jon on Facebook.