Sea lion necropsy reveals no clear answers
A dead sea lion that washed up on the beach at Refuge Cove was dissected Thursday in hopes of finding out what caused the death. The necropsy took several hours, and attracted many observers. But it didn’t provide any clear answers.
It was a windy day out at Refuge Cove. That’s not good for recording sound for a radio story, but it’s great for everyone else, because it blows the smell away. The odor of dead sea lion isn’t pleasant, especially when Gary Freitag makes the first cut into the belly of the 9-foot-long, 2,000 pound marine mammal.
“You might go upwind,” he said to some of the curious bystanders, as the air hissed out of the cavity.
Freitag is the Marine Advisory Program agent in Ketchikan for the Alaska Sea Grant program. He conducted the necropsy, with help from Mike Welsh of the National Marine Fisheries Service.
A few moms showed up with their kids, taking advantage of this real-world science lesson.
“Those are his intestines, guys,” one mother explained to her kids. “And look, see the white
part? That’s his blubber. And it keeps him super warm. It’s like insulation.”
Freitag took samples of blubber
“From that, they’ll be able to do analysis like organic contaminants, things like that. And heavy metals,” he said.
He also took samples from all the organs, and other tissue. What they didn’t save as a sample, they threw back into the ocean to feed the wildlife.
The organs didn’t reveal any secrets; they all looked healthy. Except for the heart. Initially, Freitag wasn’t sure it even was the heart, because the tissue was soft and floppy, rather than the firm muscle one would expect.
But, even that isn’t a clear cause of death.
“I think what happened where the heart was, is because it was on the sharp rock and the weight pounded on it,” Freitag said. “Because it really mashed the heart up. The heart didn’t have a consolidated structure.”
They did take a sample of the heart, so if there’s some kind of disease, testing will reveal it.
There was also no clear evidence of a gunshot wound, which had been the rumor. But to make sure, Freitag removed the sea lion’s head. It took some work, a sharp knife and a pair of brush cutters.
“It may have been shot through the eye,” he said, after the head was off. “The eye is all mangled. But that could be bird activity, it could have been the way it went onto the rocks, could have punched the eye out. There’s a million reasons why the eye is all bloody, but it also could be that a bullet went through that eye.”
Freitag will put the head underwater to be cleaned up by crustaceans. After about six months in the water, the clean skull will show whether or not the sea lion had been shot. Freitag plans to use the same cleanup technique with one of the flippers, to use for educational purposes.
The rest of the body was hauled off the rocks, and pulled closer to the approaching tide. With the body cavity opened up, it shouldn’t float, and various marine animals will take full advantage of the relatively fresh meat.
The samples Freitag took will be sent to labs in Anchorage. Quick results are unlikely.