Researchers find radioactivity in migratory tuna

Funding sought for further study on presence in marine animals

More than a year after a tsunami in Japan flooded the Fukushima Dai-ichi nuclear power plant, researchers from Stanford and Stony Brook Universities report discovering trace amounts of radioactive material in bluefin tuna caught off California's coast in August of 2011.

The Fukushima plant, which contained six reactors, experienced a series of system failures and meltdowns following the tsunami and the resulting flood, ultimately releasing radioactive materials into the surrounding ocean. The researchers think the material found in the tuna came from the Fukushima plant.

The initial idea for the study was "kind of a shot in the dark," according Daniel Madigan, a Stanford Ph.D. student at the Hopkins Marine Station in Pacific Grove, Calif., and the lead author of the report, which was published in the Proceedings of the National Academy of Sciences.

"Our expectations were pretty low," he said.

Their expectations were so low, in fact, that the team initially sampled only 15 fish, a limited sample size, Madigan said.

Their hypothesis was based on previous knowledge of bluefin tuna migration. Since young tuna typically travel from Japan eastward toward California, Madigan and his team suspected that if there were any trace elements from the Fukushima plant, they would be found in those fish.

And it seems they were right.

There were heightened levels of both cesium 134 and 137 in the local tuna population, though the team reported that these levels were not toxic for human consumption and have not harmed the fish. Cesium 134, however, can only be created by human activities, such as in nuclear power plants and weapon manufacturing. The team concluded that any cesium 134 found in the tuna was from the Fukushima plant.

But the importance of this research goes beyond the lives of migratory tuna. Madigan and his team hope to continue the study, observing cesium levels in other migratory animals such as sea turtles, whales and sharks in an attempt to further understand the true extent of the Fukushima plant's impact.

There is also the question of how the levels of radioactive material have changed in air-breathing animals, such as sea birds, Madigan said.

"We want to know what proportion of the contamination comes from gills versus food," he said, noting that it is most likely an animal's meal that passes along the radioactive cesium.

Though the study of 15 tuna has grown into a full-scale research project, it began as a bit of a fluke.

"This was actually a side project of what I'm doing," said Madigan, who primarily studies predatory fish in the pelagic, or open water, ecosystems. "Our observations turned into something much bigger."

In order to expand the research as far as Madigan and his team want to, he said they need to find some new sources of funding.

The initial study was funded through the Gordon and Betty Moore Foundation, an organization dedicated to environmental conservation both in the Bay Area and around the world, which gave Woods Hole Oceanographic Institute $3.7 million to fund research relating to the Fukushima plant. A portion of those funds were given to Madigan and his team to conduct their study, but it is unclear how much.

It is difficult to get an estimate for how much funding the team would need, stated Dan Strober, the Academic and Research News Contact at the Stanford News Service, in an email.

"The costs are hard to pinpoint because it's mostly personnel time and costs associated with acquiring samples," Strober stated in an email.

But what is clear is that further research will require additional funds, he stated.

"We have no funding going forward," Madigan said. There are, however, some potential funds "in the works" that he was not at liberty to discuss.

As far as Madigan can tell, no government agency has taken on the responsibility to sponsor this kind of research and so he and his team will have to rely on private funding to continue their work.

"It is definitely not the end," Madigan said about his team's research. "If anything, this is just the beginning."


Posted by hi, a resident of Charleston Meadows
on Jun 6, 2012 at 5:58 pm

how do you come up with the idea to test migratory tuna for radiation? brilliant!

Posted by Sharon, a resident of Midtown
on Jun 6, 2012 at 6:26 pm

Not surprising-given that we have instruments that can detect tiny amounts of radiation that are no health threat.

The real health threat to our health is the millions of tons of mercury, cadmium and other toxic metals and material that China dumps into the Pacific and the atmosphere every year.

Posted by Joe, a resident of Another Palo Alto neighborhood
on Jun 6, 2012 at 9:13 pm

So .. how much of these two isotopes of Caesium were found in the tuna?

Is the Caesium a threat to the tuna? Is the Caesium a threat to humans, if the tuna were to be consumed?

The Caesium 134 has a rather short half-life of about 2 years, and the Caesium 137 has a somewhat longer half-life of about 30 years.

All-in-all, it's not clear what the Stanford folks have found out that should concern us.

Posted by HomerSimpson, a resident of Midtown
on Jun 6, 2012 at 10:20 pm

Yummmm, tuna...

Posted by assume, a resident of Evergreen Park
on Jun 7, 2012 at 5:29 pm

people have assumed this ,they know there is rads in fish. can't stop eating what can yu do?

Posted by nucleer, a resident of Adobe-Meadows
on Jun 7, 2012 at 6:06 pm

How do we know the radiation came from Japan and not a PG&E nuke plant?

Posted by Reuters, a resident of Leland Manor/Garland Drive
on Aug 20, 2013 at 3:23 pm

"All-in-all, it's not clear what the Stanford folks have found out that should concern us."

Okay, know-it-all, all-in-all, what is the safe level for radiation for your daughter??

The tuna still are in trouble:

from Reuters:
"Contaminated water with dangerously high levels of radiation is leaking from a storage tank at Japan's crippled Fukushima nuclear plant, the most serious setback to the cleanup of the worst nuclear accident since Chernobyl. .....

The latest leak is so contaminated that a person standing half a meter (1 ft 8 inches) away would, within an hour, receive a radiation dose five times the average annual global limit for nuclear workers.

After 10 hours, a worker in that proximity to the leak would develop radiation sickness with symptoms including nausea and a drop in white blood cells."

Yum! Let it leak into the Pacific.

Posted by Barney, a resident of Atherton
on Dec 19, 2013 at 9:11 pm

So the corporate-owned media and their ban on stories about the nuclear tragedy in Japan continue.

Thanks to the net and non-US media, we learn that 50 US Navy seamen have early cancers from Fukushima, and are suing TEP.

"Fifty-one crew members of the USS Ronald Reagan say they are suffering from a variety of cancers as a direct result of their involvement in Operation Tomodachi, a U.S. rescue mission in Fukushima after the nuclear disaster in March 2011. The affected sailors are suing Tokyo Electric Power Company (TEPCO), alleging that the utility mishandled the crisis and did not adequately warn the crew of the risk of participating in the earthquake relief efforts."

Web Link

Suit is being refiled.

May the Lord help these brave US military servicemen.

Posted by Go figure, a resident of Another Palo Alto neighborhood
on Dec 20, 2013 at 1:54 pm

It seems to never fail: Americans try to rescue a population in distress, and Americans suffer for it!

TEPCO falsified the amount of radioactive water being discharged into the ocean, and of course the currents would have carried it to our coast eventually. The large, predatory fish such as tuna and swordfish always carry the most pollutants, especially mercury and radiation. It is probably unsafe to eat any fish from the North Pacific waters.

Posted by Hmmm, a resident of East Palo Alto
on Dec 20, 2013 at 9:26 pm

Hmmm is a registered user.

What's potentially troublesome is not this study, but that we don't have updated figures. It was pretty easy for the scientists in my life to debunk the alleged threat due to the microscopic radiation levels in the fish from this study. You get more radiation from your bananas.

Posted by Barney, a resident of Atherton
on Dec 21, 2013 at 1:51 pm

Hmmm.... will it be "pretty easy for the scientists in my life" to debunk the "Fifty-one crew members of the USS Ronald Reagan say they are suffering from a variety of cancers as a direct result of their involvement in Operation Tomodachi" ???

If so, please have them contact the 51 US Navy men with cancer.

I'm sure they'd like to be 'debunked'.

Posted by CrescentParkAnon., a resident of Crescent Park
on Dec 21, 2013 at 8:02 pm

People don't seem to like to read the article. Many of the questions asked in the comments were covered in the story. Not sure if they were answered or stated correctly, but they were there.

I don't mean to be unsympathetic to people with cancer, but on an aircraft carrier there are 3,200 crew - what is the expected cancer rate in that population, and until there is further information - remember, you do not contract cancer in a year or two. Most cancers start many years before there are any indication or symptoms. You can tell from the size of a tumor approximately how long that tumor has existed.

Just because someone brings a lawsuit does not mean they know what they are talking about, even if they are sympathetic and you feel sorry for them.

Posted by Hmmm, a resident of East Palo Alto
on Dec 22, 2013 at 11:03 am

Barney - what do those crewmen have to do w/concerns over the radioactivity found in the fish? You're talking about something completely different from what I am, unless you plan to become a cannibal. For those of us not exposed as they were, these microscopic amounts found 2 years ago indicate important migratory information about the fish, not warnings about exposure to us through eating the fish. That was my point about debunking. Junk science articles have been referncing this work.

Since you couldn't figure this out on your own - the difference between tracking the migratory patterns of certain fish, via small amounts of radiation, vs. what those poor men are suffering, it might be a good idea for you to get some help from the scientists in your life. In the meantime, enjoy your bananas & other fruit w/radioactivity higher than in these fish :-)

Posted by Alastair, a resident of Community Center
on Dec 22, 2013 at 1:18 pm

It is a known fact that the Russians have been dumping radioactive material into the Pacific Ocean for decades. They have usually dumped it into extremely deep water off a set of islands known as the Abyssals. How do we know the caesium was not from a Russian source?

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