Yet another gray whale washed up in Alaska this month, this time on Kodiak’s Surfers Beach. These strandings are becoming increasingly common, but scientists still don’t have a solid picture of what’s going on with the population.
Whale necropsies are a multisensory experience. Stand downwind and you’ll get the pungent smell of ocean air mixed with quickly-decomposing organs. Walk a little closer and you’ll soon see the sheer volume of blood and guts that comes out of the giant mammal.
Then, of course, there’s the squelch of blubber on the sand — and in this case, the loose-helium-balloon sound of gas escaping from a cut into the side of the whale.
“Expected, but I didn’t expect it,” veterinarian Emily Iacobucci laughed in surprise, knife still in hand. “Like, it totally makes sense, but I didn’t expect that to happen.”
Iacobucci explained that the inside of the whale was rotting, and the resulting gases have expanded the whale’s belly.
“So I just released it. That might keep happening, I’m hoping that was, like, the most explosive one,” she said.
It kept going for another two minutes straight.
This gray whale is the seventh one to show up on Kodiak this year. It’s a juvenile male, nearly 30 feet long. Veterinary pathologist Kathy Burek flew down from Anchorage for the dissection. She said despite the smell, it’s the freshest specimen she’s seen this year — dead for probably less than a week.
As of July 18, 189 gray whales have washed up dead along the West Coast this year according the the National Oceanographic and Atmospheric Administration, and scientists like Burek are still trying to figure out why.
Beached gray whales used to be relatively rare, Burek said.
“Normally most years we don’t see a single gray whale,” she said. “It’s usually every couple years we might have a necropsy.”
This year, it seems gray whale necropsies are becoming almost commonplace, but each new specimen adds a little more clarity to the picture. As gray whales complete their migration to the Arctic for the summer, Burek said many whales — including this one at Surfers Beach — have been on the thin side.
“I’ve not seen one yet that I’ve been convinced was absolutely emaciated. They look thin to me,” she said. “The blubber doesn’t have a whole lot of fat in it. The profile of the animals look a bit shrunken.”
One explanation is that the whales have outgrown their food source. And with that, she said, “You have to talk about the climate change issues, because there’s been so much change in the temperatures of the waters. Pretty much we’re seeing an ecosystem-wide change right now.”
Another possibility is the spread of harmful algal blooms around southern Alaska. Toxins produced by the algae can harm and even kill marine life. And Burek said she’s not ruling out the possibility of disease among the whales either.
But this gray whale seems to have met a different fate. Burek and Iacobucci are pretty certain an orca killed it. It’s missing its tongue — that’s a pretty common sign of orca predation — and has rake marks and large bruises along its body.
Iacobucci said even if this whale’s death seems like a one-off, it doesn’t mean that the necropsy won’t deliver answers about the larger population. She said there’s always the potential that he had multiple things going on that made him easier prey.
“That’s all speculation, but it’s just the reason why you don’t go, ‘Oh his tongue’s missing, so end of story. We can all go home.’ We can learn a lot. Even if he was killed by orcas, we can learn a lot from him.”
Back at the beach, volunteers sifted through the whale’s gooey insides to collect samples in plastic bags and small vials. For the most part, the organs looked intact. Iacobucci said some samples might be used for a chemical analysis, others to look for parasites or tissue condition.
“The one that I was just taking (was) of the eyeball,” she said, holding two halves of a cut-open eyeball in her gloved hands. “We’re interested in (it) because it helps us look for evidence of toxic algal bloom toxicity. Certain types of tissues in the body will concentrate some chemicals, so the eyeball is a nice one.”
Gray whale populations in general are higher in number than they have been in a long time. But with strandings this year well above the 18-year average, NOAA declared an “unusual mortality event” for the animals in May.
It will probably be years before scientists can make any conclusions about the recent deaths, just taking into account the time it takes to gather a statistically significant number of samples and compile the results. Each necropsy, including this one, provides a data point that helps scientists understand the whales and their environment a little better.
In the meantime, NOAA reminds beachgoers that if you see a beached whale or other marine mammal, it’s illegal to mess with the specimen yourself. Instead, they say to call the Alaska Marine Mammal Stranding Network hotline at (877) 925-7773.
Editor’s note: Necropsy samples were collected under the MMHSRP permit #18786.