Bluefin tuna caught off Calif. reveal radiation from Japan

[Catbird]

There are 2 things about this article that strike me as important. One is that the traces of radioactivity remained in the fish, despite their ability to shed it, implying that the levels were significantly higher before they migrated east. The other thing is that I suspect the study that is planned for this summer will really tell the tale. The results of that testing probably won't be published for at least a year, but hopefully someone will remember to follow up and check on it.

WaPo:

"Across the vast Pacific, the mighty bluefin tuna carried radioactive contamination that leaked from Japan’s crippled nuclear plant to the shores of the United States 6,000 miles away — the first time a huge migrating fish has been shown to carry radioactivity such a distance.

...The levels of radioactive cesium were 10 times higher than the amount measured in tuna off the California coast in previous years. But even so, that’s still far below safe-to-eat limits set by the U.S. and Japanese governments.

...But scientists did not expect the nuclear fallout to linger in huge fish that sail the world because such fish can metabolize and shed radioactive substances.

One of the largest and speediest fish, Pacific bluefin tuna can grow to 10 feet and weigh more than 1,000 pounds. They spawn off the Japan coast and swim east at breakneck speed to school in waters off California and the tip of Baja California, Mexico.

Five months after the Fukushima disaster, Fisher of Stony Brook University in New York and a team decided to test Pacific bluefin that were caught off the coast of San Diego. To their surprise, tissue samples from all 15 tuna captured contained levels of two radioactive substances — ceisum-134 and cesium-137 — that were higher than in previous catches.

...The results “are unequivocal. Fukushima was the source,” said Ken Buesseler of the Woods Hole Oceanographic Institution, who had no role in the research.

Bluefin tuna absorbed radioactive cesium from swimming in contaminated waters and feeding on contaminated prey such as krill and squid, the scientists said. As the predators made the journey east, they shed some of the radiation through metabolism and as they grew larger. Even so, they weren’t able to completely flush out all the contamination from their system.

...The real test of how radioactivity affects tuna populations comes this summer when researchers planned to repeat the study with a larger number of samples. Bluefin tuna that journeyed last year were exposed to radiation for about a month. The upcoming travelers have been swimming in radioactive waters for a longer period. How this will affect concentrations of contamination remains to be seen."

[Twoolf]

Per a CNN report, a couple things to bear in mind. Most of the Bluefin eaten in this country is from Atlantic stocks, or farm stock, not wild caught. The pacific catch is mainly to sportsmen. This really is not a big public health issue.

[linttrap]

This is just the fish species that proves that migrating fish which spend time near Japan may not be safe to eat.

You'll notice these fish were caught and tested last August. Do you think we would have been informed if the radioactivity had been higher? No, because these data were being collected by a college professor to be published. He's not turning anything loose until he gets it published.

And there are no government agencies who want to publish this kind of bad news in a timely manner. Slip it under the radar of the public well after it happens. Then people read and think---oh that was last summer. I don't have to worry about that.

There's been a pattern to this since the day of the tsunami. What we should have known when it happened is not revealed until long after it is done. In the meantime, enjoy the radiation!

[Catbird]

Originally Posted by Twoolf

Per a CNN report, a couple things to bear in mind. Most of the Bluefin eaten in this country is from Atlantic stocks, or farm stock, not wild caught. The pacific catch is mainly to sportsmen. This really is not a big public health issue.

Your point about the source of most tuna that's eaten in this country is true. My posting this wasn't a suggestion that we all quit eating tuna. But I do think that the findings are significant. Not so much because it's a public health issue, yet, but because this is a heads up for what we may be seeing some months down the road.

linttrap also brings up a good point. How long will it take for further testing to be made public? Assuming that it's actually being done, of course. Will we find out about increased levels of radioactivity months after it's actually begun showing up? The article also mentions that further testing on other species should be done. Do those other species include seafood that is more commonly harvested for consumption in the U.S.? Are those species being tested? If so, when do we find out about the results?

Lots of questions. Few answers.