Officials at the Shedd Aquarium were hoping Monday that further tests might reveal the cause of the sudden and mysterious death of a beluga whale mother, even as they formed a plan to try to keep her nursing baby alive.
Immiayuk, 14, a first-time mother who successfully gave birth to the baby, Kayavak, last August at the John G. Shedd Aquarium, died unexpectedly Sunday evening after becoming listless and refusing to eat over the weekend.
By Monday afternoon, animal trainers, hoping to get the nearly 5-month-old calf to grow up quickly, placed whole fish into her mouth and were relieved when she readily swallowed them. The trainers believe the baby, which had been getting all its sustenance from its mother’s milk, is old enough to be weaned from a milk diet.
“At this stage, we’ve decided not to try to place the baby calf on a diet of artificial formula,” said Jeff Boehm, the Shedd’s chief veterinarian. “We’re pretty confident we’ll get her on a whole fish diet rather quickly.
“In recent weeks, she had been playing with whole fish in her mouth already (the first step whale calves make in being weaned from nursing), so she is an excellent candidate for this.
“We used herring today,” he added. “She seemed to enjoy that.”
Immiayuk’s death is the latest in a string of stinging losses in the Shedd’s history of keeping belugas, which began in 1989 when a Shedd expedition went to Canada to collect her and another young female, Puiji, from Hudson Bay. Animal rights groups have repeatedly protested the aquarium’s decision to capture and breed the whales.
In 1992, two young belugas died at the Shedd when they were administered deworming medicine shortly after arriving from the wild. The first two beluga babies born at the facility, one in 1998 and one a few weeks before Kayavak’s birth, both died shortly after their births.
“The Shedd Aquarium considers itself to be a state-of-the-art facility, but it just can’t keep (belugas) alive,” said Debbie Leahy, president of Illinois Animal Action, an animal rights group opposed to keeping marine mammals in captivity. “That (the five beluga deaths) in itself should argue against keeping them in captivity.”
Leahy said her organization sent a letter Monday to Mayor Richard Daley, asking the city to ban the practice of keeping and breeding large marine mammals within the city limits.
“They don’t belong in captivity,” said Kay Sievers, head of the Animal Rights Mobilization, another group that has protested keeping the whales at the Shedd since the late 1980s.
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“They’re there just to bring in money for the Shedd,” said Sievers. “It isn’t worth the lives of these mammals to entertain a few people.”
Still stunned Monday by Immiayuk’s death, Shedd officials said they will not know for several weeks–if ever–what happened to cause her death. They had given her a complete physical during Thanksgiving week and she appeared to be in perfect health, Boehm said.
“On Saturday our trainers became concerned when Immiayuk wasn’t eating and seemed lethargic,” said Debra Fassnacht, Shedd’s vice president for communications. “Normally she’s very active and had been eating about 70 pounds of fish a day.
“On Sunday they brought her and the calf into the (off-viewing) veterinary pool so they could watch her more closely.”
Boehm said veterinary staff, lab workers and handlers were all in the shallow medical pool with Immiayuk when she died.
“They were waiting to do some diagnostic tests,” said Boehm, “when she began to list. The group gathered around her, and she simply stopped breathing.
“We’re all stunned by her death,” he added. “More than anyone, we want to know what happened.”
Sunday night officials did a necropsy (animal autopsy), examining the whale’s vital organs and systems, but preliminary results showed no hint of what might have happened, Boehm said. Over the next few weeks, laboratory tests will be done on various tissue and fluid samples taken from the whale.
“By putting all the information these tests yield in front of us, and then by putting them all into context, we hope to see something that will tell us what happened,” said Boehm. “Often it does, but sometimes we never really find out what it was.”
As soon as Immiayuk died, Shedd officials began consulting other marine mammal experts about possible steps they could take to assure the calf’s survival. They were heartened by what they found out.
Part of their plan was to allow another female beluga, 10-year-old Naya, who had been sharing a pool with Immiayuk and Kayavak since shortly after the calf was born, to swim with the calf. Belugas are very social animals, and experts elsewhere said it was important for the calf to be with other animals that she knows and is comfortable with.
“The baby beluga has a very good chance of being successfully reared,” said Brian Joseph, general curator at Point Defiance Zoo in Tacoma, Wash. Several years ago, Joseph, a veterinarian, was working at Sea World in California when the mother of a baby male bottlenose dolphin died. The baby, just two weeks older than the Shedd’s beluga, switched immediately to fish introduced by trainers, and is now a healthy adult, said Joseph.
“The bottlenose dolphin had been playing with fishes but hadn’t swallowed any yet at the time its mother died,” said Joseph. “Like the beluga calf, he was with other females he had known since birth. We physically restrained him, (put fish in its mouth) and he started to eat them immediately.
“It’s important that the (orphan) calves are around whales they know. It’s almost like family. They’re more relaxed and comfortable when they’re with individuals they know.”
Jay Sweeney, a marine mammal veterinarian who was with the Shedd expedition when Immiayuk was collected in Canada’s Churchill River in 1989, has had experience weaning nearly a dozen captive bottlenose dolphin calves by feeding them fish. All of them were less than 3 months old, younger than the Shedd’s beluga calf.
“Expertise with baby cetaceans (whales, dolphins and porpoises) is much greater today than it was even five years ago,” said Sweeney. “When you cross the line into success, many successes follow. J.J. the gray whale was a newborn who was successfully saved and raised two years ago in Sea World in San Diego. There are a number of other similar instances.”
Switching a calf suddenly from a high-fat, lactate diet to a fish diet with less fat and more protein and fiber is not as difficult a transition as scientists previously believed, Sweeney said. The fats in a mother whale’s milk are processed through her from her own fish diet, making the two diets complementary to each other.
Sweeney, who is based in San Diego, now works with bottlenose dolphins in a commercial swim-with-the-dolphins program, Dolphin Quest, in Hawaii, Bermuda and Tahiti.
“In our program with baby dolphins, in every case we have had them consuming fish by the time they are 2 1/2 months old. By the time they are the age of the Shedd’s beluga calf, they’re already eating several pounds of fish a day, Sweeney said.
“I feel so bad for the people at the Shedd. They are very capable and have just had such hard luck.”