Emaciated Orca Had Rotting Teeth and One Plastic Sheet in Its Stomach

A weak and sick killer whale that died stranded on a beach has been revealed in its necropsy to have severe gum and organ inflammation.

The necropsy—an animal autopsy—also showed that the orca's heart valve, meninges (brain membrane) and in the reproductive organs were infected and inflamed, and that the orca had an empty gut except for a sheet of plastic.

"All the orca's teeth were loose and rotting. The animal must certainly have been in real pain when eating food," Lonneke IJsseldijk, the project manager of marine mammal stranding research at Utrecht University and member of the research team studying the dead orca, said in a statement.

"The animal was very ill, besides the gingivitis (inflammation to the teeth, gum) she also suffered from several internal inflammations, including the meninges, a heart valve and in the reproductive organ. We are doing ancillary testing to investigate which pathogen or pathogens were involved; whether there was one common cause or several to explain the abnormalities we found in her organs. We need this information before we can elaborate upon causes," IJsseldijk, told Newsweek.

Orcas are large members of the dolphin family, growing up to 32 feet long and weighing up to six tons. They generally reside in the colder waters of the Northern and Southern hemispheres and live in social family groups led by matriarchs that many of them stay in for their whole lives. Orcas are incredibly intelligent animals, often teaching each other sophisticated hunting techniques and working in teams to capture prey.

Unlike other dolphins and whales, orcas rarely strand on the beach. One of their hunting tactics even involves the orca very nearly getting stuck on the sand in order to snatch prey from the shallows. However, they are more likely to strand and not be able to return to the water if they are weakened or unwell.

"Dead and ill killer whales do strand on the beach, though the majority of ill animals die in the ocean and sink. Also, other stranded killer whales have shown signs of extreme tooth wear, which has been linked to the prey they consume," Dawn Noren, a research fishery biologist at NOAA NMFS Northwest Fisheries Science Center in Seattle, told Newsweek.

The necropsy of this orca found various inflamed organs and that the orca's gut was nearly totally void.

"In the stomach there were no food remains. We found only a small plastic sheet, but that had no bearing on the cause of death. The more than 30-meter-long [100 foot] intestine was also empty. This orca had not eaten anything for days," biologist Mardik Leopold of Wageningen Marine Research said in a statement.

The killer whale was clearly very unwell when it ended up on the beach. The reasons for its sickness are yet to be determined, however, it may have something to do with its infected teeth and gums.

"There was a juvenile killer whale that live-stranded on the Washington coast in 1973—it was transported to a local oceanarium and rehabilitated—it was found to have an abscessed tooth in its lower jaw which in turn compromised its echolocation hearing ability which may have contributed to its inability to navigate and consequent beaching," Bradley Hanson, an ecologist and killer whale expert at NOAA/NMFS/Northwest Fisheries Science Center, told Newsweek.