Author’s Note: This piece was posted in March 2012. Since that time, we have been learning more and more about the extent of damage caused by the March 2011 Fukushima disaster. I am revisiting the effects of that devastating incident on our Pacific Ocean fish supply and will update that info periodically.
SUMMARY So far, in this anti-cancer investigation, we’ve been talking about pollutants from industry, which concentrate in fat. Our conclusions:
Salmon from the Bering Sea in Alaska win top prize. Next best: salmon from southern Alaska and British Columbia (except for certain species that reside in the dirty Strait of Georgia.) For you salmon lovers, pink followed by sockeye are top choices: You can eat quite a bit without consuming too much of the bad stuff.
But what about radiation in your wild Pacific salmon, which seek out the bones and muscle? Is that a concern?
For all those years (mid 40s to the 80s), the Pacific Ocean was the site of nuclear testing. Even “pristine” Alaska wasn’t spared– nuclear testing near the Aleutians, nuclear subs still decaying in the sea, fallout from the Chernobyl disaster that made its way north. Is there radiation in our wild Pacific salmon?
All wild Pacific salmon native to North America are very clean from a radiation standpoint, says Jarvis Caffrey, a radiation health specialist at Oregon State University. In fact, experts agree that up to now, most Pacific fish have been, radiation-wise, quite clean. The reason? Pacific Ocean currents are so strong and waters, vast that radiation gets extremely diluted.
BUT WHAT ABOUT FUKUSIMA? Will history’s largest accidental deposit of radiation in the ocean affect our salmon?
Caffrey has been part of an international research team tracking the trails of Fukushima In the Pacific. Understandably, he is more worried about the food supply for the unfortunate Japanese. All the evidence from Fukushima thus far shows that the effect is localized to Japanese waters.
And what are the specific concerns? When it comes to radiation in the waters, cesium- 134 and 137 are among the key elements. They stick around much longer than the short lived radioactive iodine you’ve heard about–134 for about two decades; 137 for about 300 years. (A general rule of thumb: Radionuclides remain in the environment for about 10 times their physical half lives.) These elements travel in water, with the currents, and in air, thus getting deposited in rain, and cesium-137, along with strontium-90, can both accumulate in fish. Then there’s plutonium, which can stick to particles that settle on the sea floor or to the sediments directly. Plutonium is highly reactive.
WHAT ARE SCIENTISTS FINDING?
Caffrey’s team—led by Dr. Ken Buesseler, a senior scientist at the Woods Hole Oceanographic Institution in Massachusetts and a world expert in marine radioactivity —as well as other researchers have tracked radiation up to 600 kilometres (400 miles) off Japan’s coastline. The amount they’ve found thus far does not pose a risk to humans or marine life, they say. “The levels we measured are below those thought to be of concern to humans for risk of cancer or other radiation effects,” says Buesseler. In fact, that appears to be the common opinion among scientists, although a few scientific voices are raising doubts.
But Buesseler says there is a problem: The radioactivity levels in the ocean at the power plant have not been declining in recent months. And if the surrounding waters are not clean enough, then the radioactive elements in the fish and plants will remain elevated.
“ Levels of radioactivity found in fish are not decreasing and there appear to be hot spots on the seafloor that are not well mapped,” Buesseler wrote in a recent piece on the CNN website. He calls the trend worrisome and is encouraging scientists worldwide to work together in order to understand Fukushima’s full impact. (The US National Academy of Sciences recently published his report on a June 2011 expedition off Japan.)
WHAT ARE THE JAPANESE FINDING?
Fortunately, the Japanese are being somewhat transparent. They are testing the marine life in the affected area—both fish life and plants—and posting results regularly on the internet.
As they readily admit, they’ve detected levels of radiation higher than their standards in many seaweed and fish located near the reactor. The sand lance, for example, which lives on the coastal surface and is used to make fish feed, was among the first organisms in which excess radiation was detected. The seabass–a species that dwells in the mid-level waters—also revealed high levels.
As for Japan’s salmon, so far, excess levels of radiation have only shown up in their land-locked species. (Freshwater fish have a harder time eliminating radioactive matter than saltwater species, and the material takes time to accumulate in saltwater fish that eat higher on the food chain.)
Scientists agree, however, and the Japanese numbers suggest, that the biggest concern at this point are the fish that feed on sediments at the bottom of the sea (the benthic zone), including flounder and greenling, along with filter feeders such as mussels and clams, which take in food by filtering water and accumulate toxins.
Will any of these contaminated plants or fish in time work their way up the food chain or directly onto somebody’s plate? Let’s look at that possibility.
WHAT SEAFOODS ARE THE JAPANESE SELLING?
Fortunately, the Japanese have shut down fishing in the immediate area and banned the selling of contaminated species. They appear to be engaged in intensive surveillance–inspecting fish from offshore nearby prefectures as well. And effective April 1, 2012, their standards for acceptable levels of radiation became much stricter —in the case of cesium-137, ten times as strict as US and Canadian standards.
But Japan is still exporting some fish. From where? It’s hard to know. Japan’s ban on fishing only covers an area 30 kilometres from the site, and nobody seems to know much more than that about where the fish are coming from—not the FDA, not the Canadian Food Inspection Agency. Both Canada and the US are still importing Japanese foods, including fish from their seas.
As for salmon, Japan has banned the sale of the contaminated fresh water species caught in Fukushima prefecture. But they’re still exporting salmon from elsewhere in Japan. And North America is still importing Japanese salmon and products, although the amounts are fairly small. If in doubt of your salmon’s origins, check labels and ask, including at restaurants. (You hate when people do that? Read on. )
WHAT ARE THE US AND CANADIAN GOVERNMENTS DOING TO PROTECT US?
This we know for sure: They’re not inspecting all Japanese imports.
Right after the incident, the Canadian Food Inspection Agency ( CFIA) launched an emergency plan–a sampling and testing strategy to monitor radiation in Japanese products. All food products they tested were “well below Health Canada’s actionable levels for radioactive material,” they say. In June, 2011, they discontinued that plan. Since then, products from Japan have been getting the same scrutiny as products from elsewhere. The government still monitors radiation in imported foods to the same degree it did prior to the disaster; at this point they have no plans for additional testing of foods from Japan.
And the FDA? Since March 2011, the FDA has tested 199 samples of seafood coming in from Japan (including one salmon product) and performed field exams, using radiation detectors, on 40 percent of the seafood products entering the US. To date, nothing has been of concern.
Almost 200 samples in 14 months, amid reports that radiation levels are not declining? Does that put you at ease to eat foods from Japan ?
The US government would like us to believe that there’s nothing to worry about. Its post Fukushima seafood statement still proclaims loudly and clearly that the Japanese sandlance is “the only Japanese fish with levels of radiation exceeding standards,” and it buries the truth—that many other fish exceed standards– in a statement hidden elsewhere on its site.
BEYOND JAPAN: MIGRATORY FISH
The US and Canadian governments are also not testing fish caught off our Pacific shores. Should they be?
“ Radioactive contamination from the nuclear disaster in Japan has not emerged as a food safety problem for consumers in the United States,” concluded natural resources policy experts Eugene H. Buck and Harold F. Upton in a report they prepared for the US Congress.
Neither the radiation carried through ocean currents nor the radiation carried through atmospheric currents and deposited via rainfall in North America and the Pacific is a problem, they say. (The report is dated January 2012 although much of the evidence it relies on is from the early days of the disaster.)
But the authors do raise this possibility: Migratory fish from Japan or from elsewhere in the Pacific could feed in contaminated waters and then swim to US or Canadian waters and get caught. Albacore tuna and salmon, they say, are two potential culprits.
SALMON: IS THERE A PROBLEM?
In the case of wild Pacific salmon from the US and Canada, you have nothing to worry about, says Dr. David Welch, a world expert on salmon migratory patterns. Salmon from Japan do not migrate as far as the North American coast, he says, and likewise, our North American species do not migrate as far west as Japan’s coastal waters.
Other migratory species, however, including mackerel as well as tuna, may be more cause for alarm. Should our governments be concerned about that?
WHAT’S COMING OUR WAY? THE KUROSHIO CURRENT
You have to see this map —a moving projection of the Kuroshio current, a strong ocean current that flows eastward off the coast of Japan and could be carrying many of the longer-lived radioactive elements. The current moves toward the US Pacific coast (in fact, it kept the radiation from travelling southwards), then mixes with another current and moves up to Alaska. The elements in the current are projected to arrive near the US west coast in about 4 years.
(Don’t confuse this with the debris you’ve seen; that gets pushed along faster by the wind. In fact some of it has already arrived, but many experts say it probably doesn’t present a radiation problem : The tsunami pushed the debris offshore before most of the radiation was released. )
By the time any Fukushima elements arrive here in that current, Caffrey says, they will be so diluted as to have no effect. Virtually all scientists agree.
Meanwhile, could our fish become contaminated by feeding in that current—or by feeding on fish that have fed there? Again, Welch is not concerned about our salmon. “ Nothing we currently know about salmon suggests that any North American salmon go anywhere close to the areas of higher radiation levels,” he says.
No radiation worries for now, but if you’re shopping for salmon or eating in a restaurant, you might want to make sure you’re not getting the Japanese version. (“Cherry” salmon is the species there.) As for other fish, I’m on the case. Will this bring a whole new meaning to the term “Watergate”? Click on this link if you’re too young to remember. Follow this blog for continual updates.
NEXT: Now that we’ve settled on what wild Pacific salmon to ask for, how does farmed Atlantic salmon compare? Are the concerns that surfaced in the mid 2000s about PCBs in farmed Atlantic salmon still valid? Is “organic” farmed salmon a better choice?
Our anti-cancer investigation continues…
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