Fish in Fukushima Still Contaminated

Written by on October 26, 2012 in Marine Life

UPDATE Sept 13 — The announcement from government officials and the Tokyo Electric Power Company (TEPCO) that radioactive water is still leaking from the Fukushima Dai-ichi nuclear power plant has rehashed concerns about the safety of seafood coming from the Pacific Ocean. So is it safe?

Earlier this month, South Korea announced that it is banning all fish imports from along Japan’s northeastern coast because of the leak. The ban applies to a total of eight prefectures covering more than 700 kilometers (430 miles) of coastline, even though only fisheries in the Fukushima prefecture are closed. Fish caught in the surrounding prefectures are only sold after they have past safety standard tests, but South Korea won’t accept any fish, even if they meet safety standards.

But for now, we don’t have to worry about seafood sold in the US. That’s because unsafe levels of radiation are mostly limited to bottom-dwelling fish in the Fukushima prefecture so other migratory fish, like tuna, wouldn’t have unsafe levels of radiation by the time they were caught in the eastern Pacific. 

For more information, check out FAQs on Radiation from Fukushima and 5 Things You Need To Know About Fukushima and Seafood.

UPDATE Sept 1 — Radiation levels around the plant are 18 times higher than previously thought. Learn more here.

UPDATE Aug 30 — The government released a public statement calling for the immediate evacuation of all residents within a 50-mile radius of the Fukushima Nuclear Power Plant due to the leaks. Learn more here.

UPDATE Aug 28 — What use to be a level 1 “anomaly rating” has been raised to level 3, a week after news emerged of a leak of hundreds of tons of radioactive water from one of the storage tanks at the plant. Learn more here

A fish market in Japan.

A fish market in Japan. Photo credit.

New data shows that fish caught off the coast of Japan are still suffering from the effects of the March 2011 “triple disaster.”

The magnitude 9.0 earthquake caused a 40 foot tsunami, which caused  terrible damage to the Fukushima Dai-ichi nuclear power plant.  The damage to the power plant resulted in the largest accidental release of radiation to the ocean, ever.

To help understand the lingering effects, Woods Hole Oceanographic Institution marine chemist Ken Buesseler analyzed data from the Japanese Ministry of Agriculture, Forestry and Fisheries (MAFF) that was made available to the public.  He analyzed the radiation levels of nearly 9,000 samples of fish, shellfish and seaweed from locations around Fukushima Prefecture.

Buesseler’s findings:

  • 40% of fish show radiation levels above regulatory limits (a high percentage partly because the government lowered the limits in April 2012)
  • the most highly contaminated fish were caught off the coast of Fukushima Prefecture
  • bottom-dwelling fish showed the highest levels of contamination
  • most fish caught off the northeast coast remain below limits for seafood consumption
  • some fish don’t show any contamination at all
  • in fish that are contaminated, levels do not appear to be decreasing
  • must be a continuing source of radiation from low-level leaks from the reactor site, or contaminated sediment on the seafloor

“To predict the how patterns of contamination will change over time will take more than just studies of fish,” said Buesseler.  “What we really need is a better understanding of the sources and sinks of cesium and other radionuclides that continue to drive what we’re seeing in the ocean off Fukushima.”

To learn more:

Flooded runway only days after the tsunami.

Flooded runway only days after the tsunami. Photo credit: U.S. Air Force Staff Sgt. Samuel Morse.


Copyright © 2012 by Marine Science Today, a publication of Marine Science Today LLC.

About the Author

About the Author: Emily Tripp is the Publisher and Editor of She holds marine science and biology degrees from the University of Miami's Rosenstiel School of Marine and Atmospheric Science and a Master of Advanced Studies degree in Marine Biodiversity and Conservation from Scripps Institution of Oceanography. When she's not writing about marine science, she's probably running around outside or playing with her dog. .


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