"So why do you think there are a million barrels of oil being shipped down the St. Lawrence every day?" ...  it's not just inbounds to montreal and quebec, it's also shipping along the great lakes and along the st lawrence seaway. In 2015 about 2 million tonnes of petroleum were shipped along the Montreal - lake ontario section and also 2 million tonnes or so along the seaway itself  which is not massive but it's a significant add on to the volume  http://www.greatlakes-seaway.com/en/pdf/traffic_report_2015_en.pdf  

Again, hydrocarbon traffic in/out of eastern ports dwarfs anything we have out west. Nobody bats an eye, instead they point to the impeccable safety records of hydrocarbon transport and Newfie offshore oil. Good for them, bravo. Now, why can't we do the same?