Officers of the Canada Border Services Agency (CBSA) work at marine container examination facilities in Halifax, Saint John, Montréal, Vancouver and Prince Rupert, to facilitate the movement of legitimate goods into Canada. CBSA officers apply a risk management approach in the examination of all marine containers.
This guide answers some questions about this approach: http://www.cbsa-asfc.gc.ca/publications/pub/bsf5111-eng.html.