NORWAY, P.E.I. -- The Canadian Coast Guard and Fisheries and Oceans Canada were expected to beach a dead right whale on a Prince Edward Island shore Wednesday in a bid to learn what killed at least six of the endangered mammals in recent weeks.

Tonya Wimmer of the Marine Animal Response Society said the carcass was being towed to shore at Norway, P.E.I., with the intention of conducting a necropsy on Thursday.

"For the coast guard and Fisheries and Oceans ... it is a very slow process to ensure the safety of the people on the boats and also make sure they don't lose the animal midway coming in. Some of these animals are coming from quite a ways away," Wimmer said.

Officials want to determine if boat strikes, fishing gear or a possible toxic algal bloom could be to blame for the deaths of the whales, spotted floating near Quebec's Magdalen Islands.

Wimmer said time is of the essence.

"The longer the animal is dead, the longer it may be decomposing and some of that evidence might begin to deteriorate," she said.

The first necropsy is expected to be performed on a whale first spotted on June 18.

The necropsies are being lead by Dr. Pierre-Yves Daoust with the Canadian Wildlife Health Co-operative, Atlantic Veterinary College and the University of Prince Edward Island.

Wimmer said only an internal exam can confirm what may have killed the whales, and they hope to be able to examine two or three of the carcasses.

There are only about 525 North Atlantic right whales in existence.

Right whales can grow to about 15 metres in length and can weigh up to 70,000 kilograms.

Laurie Murison, executive director of the Grand Manan Whale and Seabird Station said each whale has a distinctive face, and photos and records have been kept for many years.

"They have craggy patches on their heads in the same places we have facial hair -- eyebrows, moustaches, beards. These allow us to identify individuals," she said.

Right whales can live up to 80 years.

-- By Kevin Bissett in Fredericton.