The level of radioactive cesium isotopes in the migrating Pacific Bluefin tuna is one-10th the level the United States and Japan consider dangerous and does not pose a public-health hazard to people consuming tuna, Stanford University researchers said Tuesday.
Still, they said, it shows that migrating sea life has brought traces of radioactivity from the damaged Fukushima Daiichi nuclear reactors across large ocean distances.
"The tuna packaged it up and brought it across the world's largest ocean," Stanford marine ecologist Daniel Madigan told The Wall Street Journal. "We were definitely surprised to see it at all and even more surprised to see it in every one we measured."
Other sea life that foraged near Japan, such as turtles, sharks and seabirds, may have transported low levels of radioactive cesium from the disaster around the Pacific basin, researchers said.
Tests on migrating bluefin as well as albacore tuna, sea turtles, and several shark species will be conducted this summer, they said.