The federal fisheries department is trying to figure out what caused the recent deaths of several endangered right whales in the waters off eastern Canada.

A fisheries official says at least five North Atlantic right whales were found dead in the Gulf of St. Lawrence this month – four of them in the past week – near Quebec's Magdalen Islands and the coast of New Brunswick.

“Having five of them die, that's like almost one per cent of the population,” says biologist Cathy Merriman. “It's almost certainly going to have a negative impact on the population’s recovery.”

Merriman says it's too early to tell if the deaths are connected, but the department is doing everything it can to protect the remaining population.

“Finding out what happened to these whales and why they died is a high priority,” says Merriman. “At this time we don’t have enough information to know, but we're working with a lot of partners to find that out.”

Merriman says the department is working with partners Canada and the U.S. to find out what happened to prevent further deaths

"There's no one agency or organization that can do this," she says. "It's a pretty complex operation that's going on right now to bring everyone's expertise together to make sure we do everything we can."

DFO says it has been able to place satellite tags on two of the dead whales in order to track their movement. Skin, blubber, fecal matter, and muscle tissue samples have also been taken from one of the whales. Officials are looking at towing one of the carcasses to a location where a necropsy can be done.

Merriman says the right whale has been affected by human activities for years.

“Shipping traffic, commercial fishing, oil and gas operations – all of these things have been identified as threats to the species,” Merriman says. “And they're all things we can understand and manage.”

With files from CTV Atlantic’s Laura Brown and The Canadian Press.