The federal government recently implemented a temporary measure requiring vessels to reduce their speed to 10 knots in the Gulf of St. Lawrence. The mandatory slowdown applies to vessels that are 20 metres or more in length.
This measure was implemented after ten North Atlantic right whales died in the gulf since June 7. Right whales are an at-risk cetacean population of which only about 500 remain in the world. Preliminary examination of the dead whales suggests they were possibly struck by ships or were entangled with fishing gear.
You can read more about this issue here.
Below are links to documents and articles having to do with whale protection.
Globe and Mail article on tools used by vessel operators to reduce collision risks