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Fishing for data in the radioactive waters off Fukushima

March 5, 2014 at 6:21 PM EST
With help from fisherman and citizen scientists, researchers in Japan and the U.S. are tracking the nucleotides in the ocean creatures who swim in the plume of water tainted with radiation from Fukushima. Their research is part of a long-term effort to figure out when — if ever — certain fish will be safe to eat. Science correspondent Miles O’Brien reports.
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GWEN IFILL: Now to the second of a three-part series on the impact of the meltdown at the Fukushima nuclear power plant in Japan.

Tonight, we look at questions about the safety of fishing in the region now and in the future.

NewsHour science correspondent Miles O’Brien traveled there recently and has the story.

MILES O’BRIEN: As brisk winter mornings go, this was a fine one to go fishing. We steamed out of the port of Kashima, Japan, on the good ship Inari Maru. Our captain was Kimio Sato, a fourth-generation fisherman. His son, Kosi, was at the helm.

Their predecessors in the family business never went on an expedition like this one.

“We cannot eat the fish we catch,” he told me. “All fish must be released. We are allowed to fish only the amount necessary for inspection.”

The Inari Maru was plying troubled waters, fishing for data. It’s part of a long-term effort to figure out when, if ever, fish caught near the Fukushima Daiichi power plant will be safe to eat.

Really reeled in nets filled with flounder, but threw most of them back into the Pacific. In the end, their haul was just one small bucket, about 12 pounds of fish, headed to a lab to be tested for radionuclide.

In Japan, the radiation safety standard for fish is 100 Becquerels per kilogram, the most stringent in the world.

“We occasionally catch fish exceeding that safety standard,” says Kimio. “I don’t think there are many, though, but because we’re in the 20-kilometer zone, I think we should be cautious.”

KEN BUESSELER, Woods Hole Oceanographic Institution: The Fukushima reactor in the background.

MILES O’BRIEN: Scientists who have studied these waters wouldn’t disagree. Ken Buesseler is a senior scientist at the Woods Hole Oceanographic Institution in Massachusetts. He was part of the team 12 weeks after the meltdowns on a research expedition financed by the Gordon and Betty Moore Foundation, also a NewsHour funder.

Buesseler cut his scientific teeth studying the impact of the Chernobyl meltdown on the Black Sea.

KEN BUESSELER: And I just knew, though, from that experience was that the most important thing was to get there as quick as we could to see what was happening in the ocean at that time.

MILES O’BRIEN: He and his team have gathered sediment, core and water samples at various depths off of Fukushima during four separate voyages now. They do some preliminary work at sea, but the real heavy lifting to measure the radioactivity in the water is done in labs at Woods Hole.

CRYSTAL BREIER, Woods Hole Oceanographic Institution: This is Fukushima water. This is from our cruises this past September. We found there is still contamination.

MILES O’BRIEN: Research associate Crystal Breier is tracking two isotopes of cesium, 137 and 134. Cesium 137 has a half-life of 30 years, so it takes about 300 years to mostly disappear.

But cesium-134 doesn’t stick around as long. With a half-life of only two years, it’s all but gone after 20. So scientists can say with certainty that cesium-134 found in the Pacific today is from Fukushima.

CRYSTAL BREIER: It’s been persistent. It has not gone away. It’s still — so it’s indicating that the reactors are leaking out more cesium, and there is still a problem.

MILES O’BRIEN: The plume of water tainted with radiation from Fukushima is only now reaching the other side of the Pacific.

This has prompted an online tsunami at pseudoscience, blog rumors and wild accusations on the U.S. West Coast. This viral YouTube video shows a man waving a Geiger counter at a beach near San Francisco.

MAN: Here I am on the beach.

MILES O’BRIEN: It seems scary, but the experts say it is meaningless. In fact, the real experts are certain the amount of cesium in the plume is not and will not be a threat to marine or human health 5,000 miles from Fukushima.

KEN BUESSELER: If we get up to about seven Becquerels per cubic meter, that’s beyond what I’m actually expecting. That will be 1,000 times less than what we’re allowed to have in our drinking water.

MILES O’BRIEN: That said, like any scientist worth his salt, Buesseler would like hard data to confirm it. So he is among a cadre of scientists asking various federal agents to fund a proper scientific study on the Fukushima plume as it arrives in the U.S.

They approached the National Oceanic and Atmospheric Administration, the Department of Energy, the Environmental Protection Agency, the Nuclear Regulatory Commission, and the National Institute of Standards and Technology. All said the same thing: It’s not their responsibility.

KEN BUESSELER: One of our frustrations is our government hasn’t taken this on as something that we should sponsor in terms of our national interests. There is often a lot of finger-pointing going on. And we’re hoping in the long run we can actually make some progress to find a home, as we call it.

MILES O’BRIEN: In the meantime, Buesseler is relying on some foundation support and he’s doing some crowd-sourcing.

KEN BUESSELER: All it takes is filling up one of these containers.

MILES O’BRIEN: He launched a Web site and created these kits to make it easy for anyone to do some fieldwork.

Interested individuals and communities pay $550 for the box, gather samples, and ship them to Woods Hole for analysis. The data is shared online. So far, donors have funded 33 sample sites. But how is the radiation affecting the creatures that live in the sea, and ultimately the human beings who enjoy eating seafood?

NICHOLAS FISHER, Stony Brook University: There’s cesium-137.

MILES O’BRIEN: This one.

NICHOLAS FISHER: That’s cesium-134.

MILES O’BRIEN: In New York, at Stony Brook University, Nicholas Fisher is focused on radioactivity in fish. He studies the ultimate sushi delicacy, bluefin tuna. These amazing creatures spawn near Japan, migrate to California, then return to Japan. He measured tuna caught in San Diego four months after the meltdowns.

NICHOLAS FISHER: We were quite surprised to see that every single fish we analyzed had clear evidence of Fukushima-derived radionuclides in their tissue.

MILES O’BRIEN: This is what worries sushi lovers, but Fisher and his team measured only 10 Becquerels per kilogram of Fukushima cesium. Remember, the allowable limit in Japan is 100 Becquerels.

NICHOLAS FISHER: It’s very, very low, and it’s much lower than that from the naturally occurring radionuclides, which no one was ever worried about in the first place.

MILES O’BRIEN: But eating bottom fish, like flounder, is another matter. Cesium released at the crippled nuclear power plant has made it into the sediment. That makes it unlikely these Fukushima flounder will be deemed safe enough to catch and sell any time soon.

NICHOLAS FISHER: Those levels are very high and in some cases clearly exceed safety limits. I would certainly avoid eating those fish.

MILES O’BRIEN: Kimio Sato gave us some flounder samples, so that we could test them independently. We took the flounder over to the citizens radioactivity measuring station in Minamisoma.

Kutuhiro Yoshita chopped the fish into small pieces and put into a lead-shielded gamma spectrometer. It detects and measures cesium and all other gamma radiation emitters. The numbers were lower than expected, combined cesium in these flounder, less than 10 Becquerels per kilogram, safe enough to eat.

But fishermen here will need to catch and test a lot more flounder before they can be declared safe to eat, just part of Kimio Sato’s frustration.

“The number of fish is increasing fast because we haven’t fished for three years,” he says, “and they’re getting bigger.”

Three years ago, Kimio Sato rode out the tsunami in the wheelhouse of this boat. His wife, Fumiko, just barely escaped before their home was washed away. They now live in tiny temporary quarters. And now Kimio wonders if he has lost his legacy as well. The fifth generation of Sato fishermen may very well be the last.