Tuna may have been contaminated by tsunami-damaged nuclear react - KTIV News 4 Sioux City IA: News, Weather and Sports

When the devastating earthquake and tsunami triggered a meltdown at Japan's Fukushima Daiichi Nuclear Power Plant in 2011 seafood lovers worried about the possible impact on marine life.

Now Pacific bluefin tuna has been found to carry slight traces of radioactivity.

Scientists announced on Monday that they found radiation levels ten times higher than in fish caught in previous years.

The radiation turned up in samples of tuna captured last August off the coast of San Diego.

The radioactive cesium molecules in the fish are not thought to be damaging if consumed, according to findings published in "Proceedings of the National Academy of Sciences."

Experts say they're clear about the source.

Cesium 134 comes from human activities like nuclear power and weapons, and none was found in the Pacific for years before Fukushima.

Pacific Bluefin Tuna spawn off the coast of Japan swim eastward at breakneck speeds, and weigh more than a thousand pounds.

So, scientists were surprised the huge fish did not metabolize and shed the radioactivity.