July Update: Looking for Fukushima Contamination in Canadian Coastal Waters

This blog is based on a full report prepared by Dr. Jonathan Kellogg of the InFORM project that can be found here.

Animation of InFORM coastal monitoring results with the latest data (March and April 2016).

Citizen Science Coastal Seawater Monitoring: Seventeen more samples have been analyzed for Fukushima derived radionuclides which were collected largely in March and April 2016. No coastal seawater samples were found to contain any of the Fukushima fingerprint isotope, 134Cs (2 year half-life). As in previous months low levels of 137Cs (~30 year half-life) were present in all of the samples. These new data are consistent with past observations of an increasing trend associated with the leading edge of the Fukushima plume as it arrives  in British Columbia’s coastal waters.

Monthly averaged 137-Cs data from the BC coast collected by the InFORM citizen science network between October 2014 and March-April 2016. The dashed line shows that levels of 137-Cs have been increasing relative to previously existing weapons testing derived 137-Cs fallout at the coast over this period. Error bars indicate one standard deviation. Large error bars in February and May 2015 were months when Ucluelet BC samples were found to contain 134-Cs. Colors are the same as used in the spatial map of the data shown first in this post.  

Similar to previous reports the new samples show a steady rise that would predict that the average sample will have double the initial background concentrations of 137Cs owing to 20th century weapons testing fallout sometime 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 are also more likely to 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.

Analysis as above, but with data grouped into regions as follows:  Haida Gwaii / North Coast: Lax Kw'alaams, Prince Rupert, Masset, Hartley Bay, Sandspit, North Van Is / Central Coast: Bella Bella, Port Hardy, Winter Harbour, West Coast Van Is: Tofino, Ucluelet, Bamfield, Strait of Georgia: Powell River, Vancouver, Salt Spring Island, South Van Is: Port Renfrew, Victoria

The regional graph indicates that we see the highest activity concentrations of 137Cs shift from appearing on the west coast of Vancouver Island initially northward to Haida Gwaii more recently. As explored last month, this could indicate a northward shift of the North Pacific Current bifurcation point.

The Fukushima InFORM project will continue to monitor for Fukushima derived contamination in the northeast Pacific and Arctic Oceans and in marine biota to provide scientifically rigorous estimates of risk to environmental and public health.  This summer, in addition to Pacific salmon species, will collect and analyze sessile shellfish species (scallops, mussels and oysters) to monitor the coastline for contamination.  All of this information is made freely available at the project website.