The purpose of this post is to report measurements of radioactivity in fish caught off the west coast of Canada based on the work of InFORM team member Dr. Jing Chen. A collaborative effort between Health Canada, Department of Fisheries and Oceans Canada, and the University of Victoria was published in May 2014 in the peer-reviewed, open-access scientific journal Radiation Protection Dosimetry (link). The authors examined the activities of cesium radioisotopes (134-Cs half-life ~2 years and 137-Cs half-life ~30 years) that were released in large quantities due to the triple reactor meltdowns at Fukushima Dai-ichi Nuclear Power Plant in 2011 as well as a naturally occurring polonium isotope (210-Po) that can pose radiological health concerns for human consumers of marine fish. Samples of chum and coho salmon, halibut, sablefish and spiny dogfish were analyzed and none were found to contain detectable levels of Fukushima derived radionuclides. Radiation doses to human consumers were determined by assuming a conservative worst case scenario where Cs isotopes were present at detection limits of the measurement and found to be 18 times lower than doses attributable to the naturally occurring, alpha-emitter 210-Po. The authors conclude that the radiation dose from Fukushima derived isotopes present in fish caught in Canadian waters represent a very small fraction of the annual dose from exposure to natural background radiation. Based on these measurements, at present, Fukushima derived radionuclides in fish do not represent a significant radiological health risk to Canadians. Continue reading Looking For Fukushima Radionuclides in Fish Caught Off the West Coast of Canada
What is causing the outbreak?
Original article by Naomi Klouda of the Homer Tribune here
Scientists studying the most recent outbreak of sea star wasting syndrome along the Pacific west coast have ruled out plastics, ocean acidification and radioactivity sourced from Fukushima as likely causes of the die off. Scientists working on the problem include Pete Raimondi of the Department of Ecology and Evolutionary Biology at University of California, Santa Cruz, and Benjamin Miner, professor of marine biology at Western Washington University, who discussed their most recent work in a National Public Radio Forum. A link to the most up to date map showing the geographic extent of the outbreak can be viewed by clicking here. The most likely cause appears to be a pathogen/infection that is transmitted through the water and distributed by currents up and down the coast. At present there is no definitive answer as to the cause of the outbreak.
Citizen Scientists Should Get Involved
If you are interested in helping the scientific community document the presence of sea star wasting syndrome please visit the following University of California Santa Cruz website. Another great resource to learn more about the outbreak can be found on Karyn Traphagen’s website that provides fine photos and information.
In addition to the citizen scientist sampling network that is under construction the other pillar of the InFORM project is the collection of samples in the open North Pacific and Arctic Oceans. The first samples for radionuclide analyses were collected by University of Victoria undergraduate student Kathryn Purdon on the first leg of the icebreaker CCGS Sir Wilfrid Laurier’s annual operations in Canada’s far North.
The goal of our sampling program was to obtain a detailed information about the location and intensity of the Fukushima contaminated plume of seawater by collecting seawater across the northeast Pacific from Victoria to Dutch Harbor, Alaska and up through the Bering Strait in the Chukchi Sea in the Arctic Ocean.
60 litres of seawater was collected for each sample and processed to concentrate radioactive elements for subsequent detection by gamma spectometry.
Samples are currently on the way to the laboratory for analysis. The InFORM team acknowledges the support of Fisheries and Oceans Canada, Canadian Coast Guard and chief scientists Dr. Svein Vagle (Fisheries and Oceans Canada) and Dr. Jacqueline M. Grebmeier of the Chesapeake Biological Laboratory and the Distributed Biological Observatory for inviting us to join the expedition.