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.
- 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:
- Read the full news release from WHOI: Fishing for Answers off Fukushima
- Find the Perspectives article, published in Science, here: Fishing for Answers off Fukushima
- Check out this article from BBC News: Fukushima fish still contaminated from nuclear accident
Copyright © 2012 by Marine Science Today, a publication of Marine Science Today LLC.