Measurements undertaken as part of the InFORM project to look for Fukushima derived radionuclides in fish during our second of three years of monitoring are now complete on an additional 156 fish. Sockeye salmon (Oncorhynchus nerka) and Steelhead Trout (Oncorhynchus mykiss) (as well as some Chinook (Oncorhynchus tshawytscha) and Pink (Oncorhynchus gorbuscha) Salmon) were caught off the west coast of Canada in Summer 2015 as they were returning to their home streams and rivers up and down the coast of British Columbia. Samples of fish were obtained with the cooperation and collaboration of the Champagne and Aishihik, ‘Namgis, Nisga’a, Selkirk, Syilix, Tahltan, Taku River Tlingit, Tr’ondëk Hwëch’in, Wet’suwet’en and Wuikinuxv First Nations. These results add to the first ~100 fish collected and analyzed in 2014.

What we have found so far:

1. With the exception of 7 fish discussed in point 3 below individual fish were not found to have detectable levels of either ¹³⁴Cs or ¹³⁷Cs so average levels were calculated for all fish harvested in a given location.
2. Similar to 2014, none of the fish from 2015 analyzed thus far were found to contain detectable levels of ¹³⁴Cs a man-made radionuclide that serves as a fingerprint of the Fukushima disaster.
3. The average level of ¹³⁷Cs seen in InFORM 2015 fish samples (0.19 Bq kg^-1) is similar to the level observed in the 2014 campaign (0.21 Bq kg^-1).  As with ¹³⁴Cs, the Fukushima disaster resulted in the release of a large quantity of ¹³⁷Cs. However, ¹³⁷Cs, which has a longer half-life, was already present in the Pacific Ocean prior to the Fukushima accident because of the nuclear weapons testing fallout.
   • The ¹³⁷Cs levels observed in the 2015 InFORM samples represent a fraction of the Health Canada guidelines (1000 Bq kg^-1) and a fraction of the radiation exposure owing to naturally occurring radionuclides Polonium-210 (²¹⁰Po) and Potassium-40 (⁴⁰K) which dominate the ionizing radiation dose to fish consumers.
   • While the average ¹³⁷Cs concentration remained nearly identical from 2014 to 2015, 7 individual fish (out of 156) have shown a detectable level of ¹³⁷Cs (ranging from 0.27 to 0.60 Bq kg^-1) while individual fish from 2014 were below detection limit. Because no ¹³⁴Cs was detected in these fish it is not possible to say whether detectable ¹³⁷Cs can be attributed to Fukushima contamination or simply normal variability in contamination owing to nuclear weapons testing fallout.
4. What this means is that radioactivity from the Fukushima meltdowns has not been detected in the InFORM fish samples caught in BC waters as of summer 2015.
5. Neither the ¹³⁷Cs present in the fish nor the naturally occurring radioisotopes in fish represent a measurable health risk to consumers in Canada.

Measurements of radioactive elements in these fish and from previous years are available for download at the Government of Canada Open Data website. Continue reading Update: InFORM Monitoring Results For Pacific Salmon Collected Summer 2015 →