Festus the humpback whale was first seen in Alaskan waters in 1972 the same year Marlon Brando became Don Vito Corleone* in "The Godfather". But last week, after decades of sporadic sightings, the 40ft (12m) male washed up dead, and officials are trying to find out why.   

Festus, a humpback whale monitored in south-east Alaska for 44 years, is hauled by two National Park Service vessels after being discovered dead in the waters off Point Carolus. Image: National Park Service

A charter vessel operator alerted the National Marine Fisheries Service after Festus was seen floating in the waters of Alaska's Glacier Bay National Park

Because no obvious cause of death was visible, park staff towed the carcass to shore, where a necropsy could be performed and tissue samples taken. Stephen Raverty, a veterinarian pathologist from Vancouver, travelled to the site with the team to oversee the long procedure.

"More information on the cause of death and the condition of the whale are expected to be available after the veterinary examination," Glacier Bay National Park and Preserve Superintendent Philip Hooge said in an official statement.

It's thought that humpback whales have lifespans of around 50 years, so it's entirely possible that this long-seen leviathan had simply reached his natural end. But because the whales lack teeth (which can be used to estimate age in other mammals), it's difficult to say for certain. Upper estimates suggest the ocean giants could live some 80 years. 

Analysis of the whale's skin, blubber and blood will help park biologists rule out illness and environmental factors. "We would like to hear from anyone who was in the area and may have observed anything unusual," Hooge said.  

Image: National Park Service

Glacier Bay prides itself on being one of the safest whale refuges in North America, and with rigid regulations in place to minimise contact between humans and whales, just two ship strikes have been reported here since 2011. Still, to rule it out as a potential culprit for Festus's death, the team must also conduct a study of the animal's internal organs and tissues. 

Breaking down a humpback is not the most glamorous of jobs, and in fact, it's one we've witnessed firsthand when a ten-ton behemoth washed up off the coast of South Africa. 

(This video is not for the squeamish; watch at your discretion.)

As was the case with the South African whale, gasses had already started to build up in Festus's body before the team arrived on the scene, creating much olfactory unpleasantness. But for photographer Andrew Peacock, the experience was well worth the discomfort. 

"It was slightly sad but ultimately a very interesting process," he wrote on Facebook, adding that he felt privileged to stand witness to research that could ultimately help protect other humpbacks in the region. 

We'll be updating you as pathology results come in, so watch this space.

*An earlier version of this article mistakenly stated that the famous line, "I could have been a contender," was said in "The Godfather". I shall now hang my head in pop-culture shame for all of eternity.