A rare northern bottlenose whale has been spotted again, close to shore in Nova Scotia, about 100 kilometres from where a whale of the same species was spotted last weekend.

This whale was spotted on Nova Scotia's Eastern Shore in Spry Bay on Friday. 

Last weekend, a nine-metre northern bottlenose whale was photographed in Prospect Bay, just outside of Halifax, where it spent three days circling the area. It's not clear whether this is the same whale but experts say it's highly unusual and worrisome to see this deepwater species so close to shore.

The northern bottlenose whale is a species at risk. It usually stays in deep ocean waters — at least 800 metres deep.

Dr. Hal Whitehead, a biologist at Dalhousie University who has been studying the whales for many years, said the whale is likely a female and that she looks underweight — bad news for a species thought to have less than 200 surviving members in this part of the world.

“The chances of seeing a northern bottlenose whale from the coast anywhere in the world are virtually zero,” said Whitehead.

He said seeing this species of whale so close to shore indicates the animal is likely suffering from some kind of illness or injury.

“I think it was a once in a lifetime thing that we saw this weekend,” said Kate Mahon, who watched the mammal from her home in Prospect.

“We were getting a little concerned because he seemed to be getting slower and at one point, he actually got stuck in the shallow water where it was muddy and only about three feet deep.”

Representatives from Fisheries and Oceans Canada went to the area where the whale was first spotted, but arrived just minutes after the whale left the bay. They’re worried the whale could be hurt or could become beached if it returns to the shore.

“There’s only about 160 of them left out there on the Scotian Shelf,” said Tonya Wimmer with the Marine Animal Response Society. “It’s important for us to understand everything we can about the animals and if they’re in trouble, try to help them.”

Whitehead said the whales are very friendly and curious about boats — something whalers during the 1960s were able to use to their advantage.

This is not the first time the rare whales have been seen close to shore. In 2006 a northern bottlenose whale made international headlines after swimming up the River Thames with thousands of Londoners lining the banks of the river to catch a glimpse. 

Despite efforts to relocate the whale into deeper water, it died.