A survey of North Atlantic right whales in the waters off Grand Manan has found fewer whales are coming to their traditional summering ground.

Researchers from the New England Aquarium counted only eight whales in the Bay of Fundy over the course of 15 good weather days in August and September, yet over 300 were spotted early in the spring in Cape Cod Bay.

This is in stark contrast to the years where they tracked over 150 right whales in the late 1990s and early 2000s, said Moira Brown, senior scientist at the New England Aquarium. 

'We know they're still alive — they're out there swimming around — they're just not going to their usual summering.' - Moira Brown, scientist, New England Aquarium 

And it isn't only the numbers — Brown also noted a change in the whales' habits by their brief appearances above the water's surface.

"So we're seeing fewer right whales, we're seeing them for shorter periods of time, so this is leading us to think there is not much of a food resource for them," she said in an interview on CBC Radio's Shift.

"I think they're coming in and checking things out. They used to find food there, but now they're moving on, they're not staying in the area … They don't seem to be anchored to a feeding resource like we're used to."

For more than 30 summers, Brown has tracked the North Atlantic right whales as they make their way into the Bay of Fundy to feed. The latest survey efforts are in line with 2013, when only five whales were sighted off Grand Manan.

Gulf of St. Lawrence sightings

While still endangered, the whales that travel the eastern seaboard from Florida to the Gulf of Maine have had a stable population in recent years.

But rising ocean temperatures could be contributing to a decline in plankton, which are the preferred source of food for the whales.

Brown suspects that's leading to a change in migration patterns.

Surveyors observed an increase in whale sightings in the Gulf of St. Lawrence, she said.

"We know they're still alive — they're out there swimming around — they're just not going to their usual summering areas," said Brown.

Fisheries and Oceans is continuing efforts to track the whales by asking for the public's help.

It has a campaign to have fishermen, whale watching tours and others on the water report any sightings. Hundreds of posters about the effort have been put up on wharves across Atlantic Canada.

A free mobile application for Android and i-Phone devices, called Whale Alert, can also help people chart and identify whale sightings.

The right whale has no dorsal fin, a v-shaped blow hole and distinctive patches of rough skin that grow in the area of its mouth that helps scientists identify it.