Chicago's Shedd Aquarium releases first findings in beluga whale deaths, including 2 rescued from Marineland

The Shedd Aquarium released the first set of preliminary findings from necropsies performed on two beluga whales rescued from Marineland in Canada who died after their transfer to Chicago.

The park in Niagara Falls, Ontario, shut down in 2024 after its owners died, but remained in possession of the whales. When it ran out of funding to properly care for the whales, it warned that it might be forced to euthanize them if they couldn't be relocated.    

Eight whales were brought to the Shedd from the defunct Canadian park in two groups in July and August. On Aug. 26, Shedd officials announced that the 23-year-old Peekachu had died in their care. On Sept. 3, they announced two more belugas – 20-year-old Rain and 34-year-old Beethoven – had died.  Rain was another rescue from Marineland, while Beethoven was a longtime member of the Shedd beluga pod.

A fourth beluga, a 26-year-old female named Osiris, died Monday, the Shedd announced. Osiris was also rescued from Marineland.

Friday, the aquarium released its first findings from necropsies performed on Rain, Peekachu and Beethoven.

Shedd officials said microscopic examination of tissue and organ samples taken from Peekachu and Rain found chronic inflammatory disease in their gastrointestinal systems, which was significant in Peekachu and severe in Rain.

Based on the samples, Shedd scientists believe the disease had likely been present in the whales for an extended period of time, potentially months or years, and began before they arrived at the Shedd over the summer.

The disease compromised their health and made them even more vulnerable and sensitive. Officials said that food intake is an important way to measure whales' health but can't on its own show if they're effectively digesting food or absorbing nutrients and water. While they are aquatic mammals, belugas get their hydration and water intake from their food, so not eating enough can lead to potentially fatal dehydration, Shedd officials said.

The report also says foreign objects were also found in Peekachu's stomach, including bird feathers, sticks and large, porous rocks. Officials said she could not have ingested those objects at the Shedd, and they believe they were already present in her stomach when she was rescued.

Pathologists found small flecks of a material that could be paint in Rain's stomach, but not the kinds of large objects they found in Peekachu, the report said.

Shedd officials do not believe the foreign objects directly contributed to Peekachu's death but remain relevant because of how important regular nutrition is for belugas, and because they may have had an effect on the gastrointestinal illness found.

The results from Beethoven's necropsy were different, the Shedd said, finding health changes associated with aging, including to his cardiovascular system. Specialists and veterinarians at the Shedd are still working to understand what contributed to Beethoven's death. They said at this time they do not believe Beethoven's death is connected to the rescued whales.

The Shedd also emphasized that thusfar they have not found any evidence of communicable disease connecting the three deaths. They said the rescued whales were screened for known communicable diseases before they were brought to Chicago, and the preliminary necropsy results have not found any additional evidence of disease. They said they are conducting additional testing for a broad range of fungal, viral and bacterial diseases.

The necropsy process is currently underway for Osiris, and Shedd's report emphasized that this set of findings is also preliminary, as samples have been sent to specialized labs for further testing, which then must be compared to and considered alongside the rest of the results.

The aquarium said they will continue to update the public with findings as they get them.