In part one we concluded that while there are issues, some of which may be worse in some areas of the world, farmed fish in the Pacific Northwest are relatively non-toxic and nutritious for the budget conscious as well as beneficial for restoring wild populations. In part 2 we will review the radiation levels following the Fukushima nuclear disaster.
What about the Fukushima nuclear disaster radioactivity?
Anyone who uses Facebook has surely seen articles about the massive poisoning of the Pacific Ocean following the meltdown at Fukushima. Pictures of fish with open sores as well as stories that the reason we have not seen the die off is that crabs and other bottom feeders have eaten the bodies of the fish before they have a chance to wash up on shore, (Guy, 2017). Additionally, there have been claims that no one is even monitoring the ocean and its inhabitants for radiation, (Guy, 2017). We certainly are justified in mistrusting agencies that depend on fishing, fish consumption, and tourism. So, what has been measured, who is doing the measuring, and most importantly, can we feel good about sautéing up that Coho in the freezer?
According to Allison Guy from Oceana.org, Japan caps foodstuffs radioactivity at 100 Becquerels of activity per kilogram of fish. The United States limits it to 1200, (Guy, 2017; Conca, 2013, Ministry of Health, Labor, and Welfare, n.d.). Globally the average limit is 1000 Bq/kg while the EU sets the limit at 1250, even higher than the U.S., (Conca, 2013). And just what is a Becquerel (Bq) anyway? There are a lot of terms to describe radiation and to make matters worse, there are terms for the same thing in both common US measurement and System International (SI). Some refer to the radioactivity in the contaminated item, such as the Becquerel (Bq/kg) (SI), the curie, and the Rutherford. Others refer to the exposure one has received, the coulomb/kilogram (SI) and the roentgen. Still, others refer to how much was absorbed by the tissue such as the gray (SI) and the rad. And finally, others refer to the dose equivalent which is the minimum amount known to result in cancers and chromosome damage, the sievert (SI) and rem (roentgen in man). (Radiation Emergency Medical Management, 2019). Why so many terms? Scientists use them to come up with mathematical formulas to determine probabilities and likely outcomes which enables them to set guidelines on limits of activity in foods or set limits of exposure for nuclear workers.
Okay, so back to the fish! As it turns out, there was an increase in the radioactivity of the fish shortly after Fukushima, but it went back down to normal background radiation levels rather quickly because the radionuclides had short half-lives and also due to dilution by the ocean, (Wada et al., 2016; Fisher et al., 2013; Geggel, 2018; Wild Alaskan Salmon Company, 2019). Normal background radiation? Yes, radioactivity is everywhere naturally, in foods, soils, building materials, and even in us. The most radioactive food is reportedly Brazil nuts, followed by bananas, (Vitz et al., 2019). That lovely new granite counter top in the kitchen is likely radioactive as are the bricks that façade the house, (World Nuclear Association, 2019). Of the isotopes released from Fukushima, those of greatest concern were iodine-131, cesium-134, and cesium-137. The half-life of iodine-134 is 8 days, cesium-134 is 25 months, but the cesium 134 is 30 years, (Geggel, 2018). The US was already contaminated with cesium-137 due to the nuclear testing in the 1950s and 1960s, (Geggel, 2018).
Pacific Bluefin tuna (PBFT) were tested in California after Fukushima and found to have 10 Becquerel’s of cesium-137 activity per kilogram of fish. A year later tests revealed the activity at a mere 2.7 Bq/kg. The dose of radioactivity from consuming a serving of PBFT contaminated with 4.0 Bq/kg of cesium-134 and 6.3 Bq/kg of cesium-137 yielded 3.7nSv. which amounts to 5% of the exposure from an uncontaminated banana, (Fisher et al., 2013). Tuna from Japanese waters after the disaster had 15 times more radioactive cesium, hence, above Japanese government limits, but below U.S. ones! No fish captured in Fukushima have surpassed safety limits since 2015, (Fisher et al., 2013).
Loki Fish Company of Seattle and Vital Choice Wild Seafood of Bellingham performed their own testing on samples of catch. Two of the seven that Loki tested were positive, but at levels far below the FDA limits; 1.4Bq/kg for cesium-137, and 1.2Bq/kg for cesium-134. Limits are 370 Bq/kg, (Denn, 2014). Vital Choice had testing performed six times from 2012-2016 and found all samples to be safe. As of 2016, Vital Choice found only trace amounts of cesium-137 in a sample of Chinook salmon and while sockeye and tuna were none detected, (Vital Choice Seafood, n.d.).
Discussion
Aquaculture has come a long way and there have been many improvements, however, alignment with sustainable ethical practices has not occurred in farms worldwide, (Martinez-Porchas & Martinez-Cordova, 2012). Wild fisheries are also problematic as many unethical practices take place in poorly regulated, poorly monitored areas. Practices such as use of bottom trawling, loss of fishnets, release of capture wastes, fuel leakage, massive overfishing to the point of depletion, and bycatch of non-target species, (Garcia & Rosenberg, 2010). The improvements in sustainability in both aquaculture and wild fisheries have taken place in developed nations, while worsening in developing ones, (FAO, 2018). According to the FAO, the most sustainable wild fisheries are in Eastern Central Pacific, Western Central Pacific, Northeast, Northwest, and Southwest Pacific with less than 17% of their stock are overfished, (FAO, 2018). With much of the word’s wild fisheries over exploited, aquaculture is a valuable tool to ease the strain on the global fish stock and as algal and insect-based meals become available, pressure on fish for fishmeal will go a long way to replenishing global fish population, (Beal et al., 2018).
Many agencies have been monitoring the radioactivity of the fish and water from the PNW, such as Alaska Department of Health and Social Services, California Department of Public Health, Canada's INFORM Project, Oregon Public Health, Woods Hole Oceanographic Institution, (WASDOH, 2017). The radiation scare appears to be just that.
Thus, after a bit of research, well… a lot of research actually, fish are back on the dinner menu. All that is left is to decide if one will choose wild or farmed. While farmed is safe when consumed 2-3 times per week and testing has shown it to be nutritious, it is not what most would call natural or organic. As 80-90% of the soy and corn grown in the US is genetically modified, (United States Department of Agriculture, 2019), it is, therefore, likely that the corn and soy used in fishmeal is also. Add to that the additives in fishmeal such as enzymes and isolated carotenoids. One of the reasons why farmed fish create so much pollution is the low digestibility of the grains in the fishmeal. Synthetic enzymes are added to help, (DSM, n.d.-b), however, we are still forcing unnatural food on them. Additionally, synthesized isolated carotenoids such as astaxanthin are added to the pellets to color the salmon flesh like their wild counterparts, otherwise the flesh would appear grey. Fish need astaxanthin but usually get it from krill, rather than an isomer of astaxanthin, (Megdal et al., 2009). The question is the same as for a human taking an isolated vitamin or mineral supplement; if it doesn’t come like that in nature, what delicate molecular balance is being overlooked that we are as of yet unaware of? And it’s not just fish, a company that makes synthetic pigment for farmed fishmeal also make it for chickens so that the egg yolks look deep yellow-orange. They even make color wheels like paint chips to help growers choose the color they want their fish flesh/egg yolks to be, (DSM, n.d.-a). This seems like trickery, the same as adding synthetic fragrances to factory foods to make them smell like the real thing.
Stories of food fraud are rampant these days, and salmon are no different. There have been reports of farmed Atlantic being sold as Wild Alaskan, (Megdal et al., 2009), thus, if you choose wild, your best bet is to know your fisherman and an easy way to do that is through farmer’s markets.
Conclusion
Eating salmon is better than not eating salmon. While there are reports of suspect quality of farmed salmon, those farmed responsibly in the PNW and with good quality feed are safe, affordable, and nutritious. With fears of radiation eased, one may feel free to purchase wild salmon rather than farmed, if natural organic foods are preferred. Bon Appetite!
Gretchen Kurtenacker, MS, MLS(ASCP), MT(AMT), NTP(NTA) is a Medical Laboratory Scientist who holds a B.S. from the University of Cincinnati in Clinical Laboratory Science, an M.S. in Health & Nutrition Education from Hawthorn University and is currently working on a D.Sc. in Holistic Nutrition, also from Hawthorn University. Her interests include food anthropology, food & the environment, and elder nourishment. Gretchen lives in the First Hill neighborhood of Seattle where she enjoys the incredible selection of local, artisanal, sustainable foods available within walking distance of her home.
References for Part 2
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Photo Credit:
Fukushima InFORM. (2018, March 11). Monitoring Fukushima contamination in Pacific salmon and soil in British Columbia. Retrieved from https://fukushimainform.ca/2018/03/11/monitoring-fukushima-contamination-in-pacific-salmon-and-soil-in-british-columbia/
