Dead orca calf being studied in Alaska
The examination may offer clues to why very young killer whales die.
Anchorage Daily News
ANCHORAGE — 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 its small size and good condition.
“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,” said Judy St. Leger, director of pathology and research for SeaWorld, who has studied killer whales for 13 years.
In Alaska, such tests have been done 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. It was 7 feet, 3 inches long.
The tribal government, part of a network of organizations that deal with stranded marine mammals, alerted Mahoney.
St. Leger and other experts were consulted. They decided they wanted to study it extensively.
The National Marine Fisheries Service paid to fly it from St. Paul to Anchorage Thursday night.
It weighed in at 300 pounds, Mahoney said. She said its small size — orcas are typically bigger than that at birth — indicates it was very young, probably newborn.
The CT scan will provide an internal picture of the whole whale, St. Leger said in a telephone interview. She was in New York but said another researcher, British Columbia veterinary pathologist Stephen Raverty, was flying in for the work on the whale.
“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 will be used in ongoing research.
SeaWorld has been studying orcas for 50 years, St. Leger said. She’s working with Raverty and an expert from the University of California, Davis, to develop new protocols for orca necropsies.
“This is a very unusual opportunity to look at the skull of a young animal,” St. Leger said.
The MRI should provide images of the animal’s brain, if it is in good condition, she said.
The young whale is a special case, she said. “We know next to nothing about why they die.”
After the CT and MRI tests, Kathy Burek, an Eagle River-based veterinary pathologist, planned to lead an extensive necropsy.
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 a “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 human patients return.
On St. Paul, the 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.
Orcas come around when the fur-seal pups are in the water. “It’s easy food for them,” Lestenkof said.
The other young whale’s bones will be dug up next month by students as part of the Bering Sea Days science program.