While some whale rescue missions have happy endings, many stranded cetaceans can't be saved, leaving scientists with the often tricky task of determining cause of death.

This rare Cuvier's beaked whale died shortly after stranding on a Canadian beach earlier this month, and local experts recently performed a necropsy to figure out what went wrong.

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Image: Marine Animal Response Society via Facebook.

The animal was initially spotted alive by local residents on a beach in Nova Scotia, but died before wildlife officials arrived on the scene. This is the first documented Cuvier’s beaked whale (Ziphius cavirostris) to wash up on the country's eastern coast, giving local scientists a rare opportunity to examine a species that is usually difficult to track and study.

"It was a sad but incredible experience to see this rare species up close as they are normally found hundreds of miles offshore in very deep water and are quite elusive, making sightings of them very rare here," explains the Marine Animal Response Society (MARS), whose team worked with other experts to examine the whale. Local veterinary students also got the chance to sit in on the procedure.

Cuvier’s beaked whales are deep-diving creatures rarely seen near the shore, so the animal's appearance in coastal waters was the first clue that something had gone wrong, the team adds. 

"Conducting a necropsy was important, not only to document this incredibly rare animal, but also to try to determine the cause of death," says MARS. 

Unfortunately, the necropsy did not turn up any obvious signs of disease or injury, so it's still not clear why this young male died, though further microscopic tests might still shed light on the mystery. 

"Sadly, we did find a small amount of rope in the stomach of the animal, though it was unclear if it contributed to the death of the whale," says the team.

This specimen will now make its way to the New Brunswick Museum, where the skeleton will be cleaned and assembled for display in the museum's whale collection.