Marine Atlantic is getting ready to take action if a significant number of endangered right whales are spotted in the Cabot Strait.

Spokesperson Darrell Mercer said Marine Atlantic has received confirmation that the right whales have left their wintering area off the coast of Cape Cod, Mass., and are expected to move through the Cabot Strait to the Gulf of St. Lawrence over the next few weeks.

The Department of Fisheries and Oceans said Tuesday a right whale was spotted off the coast of eastern Cape Breton during an aerial survey.

Marine Atlantic's director of fleet operations met with staff from Transport Canada and DFO Tuesday.

"They've advised us that, as the Cabot Strait is more of a transit zone for the whales, they are more or less moving to their feeding grounds," said Mercer. "At this stage, we have been told to exercise caution, and of course we have people on watch constantly trying to see if there are any whales in the area.

"If we see any right whales … we report those immediately to the federal government so that they may take additional measures," he said.

Marine Atlantic has personnel on the bridge to watch for small craft. For the next few weeks they will also be looking for right whales. (Marine Atlantic)

Those measures could include reducing the speed of Marine Atlantic ferries to 10 knots from the normal 14 to 16 knots. If that happens, customers will be warned about the slower crossing time and the impact on schedules, said Mercer.

"If we need to move in that direction to protect the whales, we will certainly do that."

Marine Atlantic was prepared to take the same steps last fall during the whales' migration south, but aerial surveys determined the whales had migrated without any long-term presence in the Cabot Strait, so there wasn't any need to reduce speeds, Mercer said.

In the last year, at least 18 North Atlantic right whales have been found dead off the coast of the U.S. and Canada. Scientists believe human activity, including shipping and fishing, are the primary cause of the deaths.

Marine Atlantic will continue to have weekly meetings with DFO and Transport Canada as long as the whales are migrating through the Cabot Strait.