Environmental groups say a new international ban on using a highly polluting fuel in Arctic waters is full of gaps.
They say Canada should refuse to take advantage of loopholes the International Maritime Organization has agreed to make part of the ban on heavy fuel oils.
The loopholes allow countries with Arctic coastlines continue to use the fuel until 2029.
Heavy fuel oil is a major source of so-called black carbon — soot particles that land on and darken sea ice, hastening its melt.
Andrew Dumbrille of the World Wildlife Fund says eliminating heavy fuel oil could cut black carbon almost in half.
Most Arctic countries, Indigenous groups and environmentalists supported a stronger ban.
Dumbrille says the loopholes were granted after heavy pressure from Russia, where most Arctic shipping occurs.
Transport Canada was not immediately available to say how it would implement the new regulations.