Pacific Swell | Southern California environment news and trends

Radioactive tuna from Japan reach California

Bluefin tuna.
Bluefin tuna.
AFP/Getty Images

With plastic and debris from last year’s tsunami in Japan already causing trouble on American shores, there’s a new cause of domestic concern from that devastating event. Researchers have found “low levels” of radiation in bluefin tuna along the California coast, raising fears that the fish brought the radiation — the result of the tsunami-damaged Fukushima nuclear power plant — across the Pacific Ocean quicker than water or even wind.

As reported by Reuters, small amounts of cesium-137 and cesium-134 were found in 15 tuna caught in the vicinity of San Diego last August, four months after the disaster in Japan and far outpacing ocean and air debris.

Researchers conducting the study claim that while the tuna were measured to contain five times the amount of cesium-137 than normal, the radiation is not enough to harm people if eaten, and are “far less” than general Japanese safety levels.

"I wouldn't tell anyone what's safe to eat or what's not safe to eat," said Daniel Madigan of Stanford University's Hopkins Marine Station and lead author on the study to Reuters. "It's become clear that some people feel that any amount of radioactivity, in their minds, is bad and they'd like to avoid it. But compared to what's there naturally ... and what's established as safety limits, it's not a large amount at all."

Bluefin tuna only spawn in the western Pacific, and often head east towards California following food sources. Using the size of the radioactive fish (an average of 15 lbs), the scientists could glean that these were young tuna that left Japanese waters approximately a month after the power plant disaster during the tsunami last year.