We have now processed and released results from over 250 samples collected through the InFORM network! New data, from April and May samples, did not reveal any waters with the Fukushima fingerprint isotope, 134Cs (2 year half-life). Low levels of 137Cs (~30 year half-life) were present in all of the samples. These new data continue to lie along the increasing trend which indicates that the leading edge of the Fukushima plume is in BC’s coastal waters.
The steady rise allows us to forecast that the average sample will have double the initial background concentrations of 137Cs this summer. While still far below the 10,000 Bq m-3 level of concern for cesium radionuclides in drinking water, these more contaminated samples should also more regularly contain the Fukushima fingerprint isotope, 134Cs.
While the increasing 137Cs trend is clear for the whole coast, it is also evident that each region is telling the story of how ocean waters circulate in coastal British Columbia.
Looking at this regional graph it would appear that an event occurred during February and March that introduced less contaminated waters during that time over the western and southern Vancouver Island stations. We are investigating what may have been the source of the this anomalous water, but have yet to identify a cause. An early hypothesis for the cause of this was that the North Pacific Bifurcation may have shifted, or that a medium sized coastal eddy brought lesser contaminated water to the area during this period. However, the coastal ocean is a dynamic place, as seen in the below animation of satellite surface current observations . These observations, while interesting, do not provide enough evidence to strongly support either hypothesis. Further work is needed to decipher what may have happened.
Fish samples are starting to come into the Trudel lab at Nanaimo for processing and the first batch was sent off to InFORM members at Health Canada kicking off the 2016 analysis season. As with previous years, InFORM investigators at the Radiation Protection Bureau will expedite the analyses of these ~100+ samples (we won’t know the final number until the season is over).
Fellow investigators at Kelp Watch 2015, released results from their final sampling which occurred earlier this spring. While all samples contained trace (<1 Bq kg-1) levels of 137Cs, the Fukushima fingerprint, 134Cs was not found in any samples. We congratulate the Kelp Watch monitoring team on a well done program. You can read more about their findings here.
Results from 7 fish samples collected in early 2016 did not show detectable levels of Fukushima Radiation according to the Alaska Department of Environmental Conservation. These pollock, cod, and herring were caught in the Bering Sea and Gulf of Alaska. Read the full post here.
Undergraduate researcher, Saskia Kowallik, completed a wonderful research cruise on the CCGS Sir Wilfred Laurier last month between Sidney, BC and Barrow, AK. In addition to her new collection of photos, stories, and shellback status, she also collected 39 new InFORM samples which will be processed by Dr. John Smith’s lab at the Bedford Institute for Oceanography. Read about her experiences as she looks forward to, enjoys, and reflects on the cruise.
Still to come this August is the research cruise out to Ocean Station Papa in the NE Pacific. Undergraduate researcher, Sara Zeidan, will be aboard collecting InFORM samples for us. This will be her first time to the Pacific Coast and we are hopeful that satellite communication will allow for a few more updates from the ship. Check back on our blog or follow our Facebook or Twitter feeds to make sure you don’t miss out.