The likely scale of the radioactive plume of water from Fukushima due to hit the west coast of North America should be known in the next two months.
Only minute traces of pollution from the beleaguered Japanese power plant have so far been recorded in Canadian continental waters.
This will increase as contaminants disperse eastwards on Pacific currents.
But scientists stress that even the peak measurements will be well within the limits set by safety authorities.
Since the 2011 Fukushima accident, researchers from the Bedford Institute of Oceanography have been sampling waters along a line running almost 2,000km due west of Vancouver, British Columbia.
And by June of last year, they were detecting quantities of radioactive caesium-137 and 134 along the sampling line’s entire length.