Dead killer whale calf is getting extensive study, including an MRI

ldemer@adn.comSeptember 7, 2013 

On Friday evening, after all the human patients were finished for the day at the Alaska Spine Institute's imaging center, a dead killer whale calf underwent a CT scan and an MRI.

The whale offered a rare opportunity for extensive study, both because of the small size and good condition.

A big team drew on experts from British Columbia, University of Alaska Fairbanks and the aquatic park SeaWorld. Some worked into Saturday morning on the University of Alaska Anchorage campus collecting samples during a necropsy done after the image scans.

"It's very sad when a baby whale dies, but the amount of scientific information we are going to be able to get over the next 24 hours is going to be tremendous," Judy St. Leger, SeaWorld's director of pathology and research, said Friday before the tests began. St. Leger, who has studied killer whales for 13 years, was in New York and participated in the work on the young whale by phone.

The orca was probably only a couple of days old, Kathy Burek, an Eagle River-based veterinary pathologist who helped in the necropsy, said Saturday afternoon. It had never nursed, but had breathed so was born alive, she said. The whale was thin, with only a thin blubber layer, and appeared to be suffering from a nutritional deficit.

Why did it die?

It had fluid in its lungs and may have drowned, though the fluid also could have resulted from an ailment, Burek said. The nutritional condition also is key, she said. The whale may have been premature. Maybe the mother wasn't able to eat enough late in the pregnancy. Maybe it was separated from her at birth. Maybe it had an infection.

"We won't have definitive results for a while. It's not like on CSI," Burek said.

British Columbia veterinary pathologist Stephen Raverty -- who along with St. Leger and a researcher with the University of California, Davis, is creating new protocols for killer whale death studies -- flew up for the work on this whale. He ended up leading the necropsy.

"For me it was a really good learning opportunity to see one on one how they want to have those extensive necropsies on killer whales," Burek said.

In Alaska, such imaging tests have been before on beaked whales, but only on the heads because they were too big to fit into the machines, said Anchorage-based whale biologist Barbara Mahoney of the National Marine Fisheries Service.

"It's to take advantage of a portable killer whale. Usually they are so much bigger," said Mahoney, who picked up the orca calf Friday at Stevens International Airport in a government truck.

The young whale was found Tuesday washed up on St. Paul Island in the Bering Sea. A tour guide leading a group of birders along a beach at Northeast Point called it in, said Pamela Lestenkof, eco manager for the tribal government of St. Paul.

The whale was in good condition, "fresh dead" and not smelly, Lestenkof said.

The tribal government, part of a network of organizations that deal with stranded marine mammals, alerted Mahoney. St. Leger and other experts in killer whale pathology were consulted. They decided they wanted to study it extensively. The National Marine Fisheries Service paid for ACE Air Cargo to fly it from St. Paul to Anchorage Thursday night.

It measured 6 feet, 8 inches, long, Burek said. That's a bit shorter than locals had reported. It weighed in at 300 pounds, Mahoney said.

The whale's condition enabled technicians to get excellent images of the anatomy that will be studied over time, Burek said.

The CT scan will provide an internal picture of the whole whale, St. Leger said in a telephone interview.

"We're specifically interested in what we call modeling the internal organs of the animal," St. Leger said. "Is there anything that is out of place? Is there any inappropriate bruising or hemorrhaging or do we see gas accumulations in an area where we don't expect to see them?"

The CT scan also provides a look at the skeleton that is used in ongoing research. SeaWorld has been studying killer whales for 50 years, St. Leger said.

"This is a very unusual opportunity to look at the skull of a young animal," St. Leger said. The studies should show whether the orca came from a resident pod, or whether it was from a transient line, which tend to travel alone or in small groups.

The MRI provides images of the animal's brain, she said.

The young whale is a special case, she said. "We know next to nothing about why they die."

The Alaska Spine Institute's University Imaging Center donated the use of its facilities for the effort, said Lesa Johnson, the institute's administrator. Radiologist Harold Cable is "an real animal lover," she said. "He's just as jazzed as he can be about the opportunity to do this."

The staff thought they were getting a frozen whale, so weren't concerned about the smell, Johnson said. As it turns out, the whale was shipped out quickly so it wasn't frozen. Mahoney said it was well wrapped for transport and the truck bed didn't stink.

"It's after patient hours," Johnson said. "We're fine with it. We're laying down plastic." Everything will be sterilized before patients return.

Kate Wynne, a Kodiak-based marine mammal specialist and UAF professor, video-taped the whale work to show the people on St. Paul. Russ Andrews, a UAF professor connected with the Alaska SeaLife Center in Seward, came because of his interest in studying remote monitoring, Burek said. The U.S. Fish and Wildlife Service sent a technician. University of Alaska Anchorage graduate students helped.

On St. Paul, the whale calf was the second one found dead on a beach in the last couple of years, Lestenkof said. The other one was too badly decomposed to study, so it was buried. Orcas come around when the fur seal pups are in the water.

"It's easy food for them," she said.

The other young whale's bones will be dug up next month by students as part of the Bering Sea Days science program.

Reach Lisa Demer at ldemer@adn.com or 257-4390.

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