CHICAGO — Osiris, a 26-year-old female beluga whale, died at the Shedd Aquarium on Monday. The aquarium announced that Osiris was the third whale to die at the facility after being rehomed from Marineland in Canada.

Peekachu and Rain died at the Shedd Aquarium in late August and early September after arriving from Canada. Another beluga whale that had lived at the Shedd Aquarium for decades died around the same time as Peekachu and Rain. A fourth whale that was moved out of Marineland in July has died after struggling with its health since arriving at her new home in Chicago, the aquarium said Monday.

Osiris was classified as a “whale of clinical concern” upon her arrival at the Shedd Aquarium. She did not eat as consistently as other whales, which complicated efforts to keep her well-fed and hydrated. The aquarium said "Osiris experienced periods of meaningful progress, both nutritionally and socially, but her overall condition remained closely monitored." The aquarium added that when Shedd was asked to help with this rescue, they understood these animals arrived with significant vulnerabilities and that the outcome for every individual could not be guaranteed. The aquarium said it will conduct necropsies on the deceased whales and share the results when confirmed.

Thirty whales were moved from Marineland in Canada to aquariums in the U.S. and Spain this summer. The Shedd Aquarium took in 10 of the 30 belugas and four dolphins from Marineland. The Georgia Aquarium and SeaWorld locations in San Diego and San Antonio accepted whales from Marineland.

Oceanogràfic de València took in two beluga whales from Marineland, including Jelly Bean. Two rescued whales at the Georgia Aquarium showed decreased appetites and were examined, but no issues were found. Whales at SeaWorld are in “stable health,” according to AnneMarie Iturrizaga, a spokesperson for the company.

Marineland is a park and zoo in Niagara Falls, Ontario, that announced it was for sale in early 2023 and closed to the public in late summer 2024. Twenty whales, including 19 belugas and one killer whale, died at Marineland since 2019, according to provincial government data. The Canadian government approved an agreement earlier this year to move its last captive whales out of the country to avoid euthanasia.

Aquarium personnel traveled to Marineland to examine health records in preparation for the move. Rescued belugas were transported in custom-made slings and temperature-controlled containers. Aquarium staff have monitored the health of the rescued whales minute-by-minute since their arrival.

Within 30 days of the whales’ deaths, the aquarium must formally submit their names and causes of death to NOAA Fisheries. The Shedd Aquarium must provide copies of necropsy reports to NOAA Fisheries upon request. Beluga whales are particularly vulnerable to changes in their environment, such as climate change, pollution, and stress, according to the National Oceanic and Atmospheric Administration.

Beluga whales native to the Cook Inlet on Alaska's coast are classified as an endangered species. The population of Cook Inlet beluga whales declined by nearly 80% from 1979 to 2018.

Why It Matters

The deaths at the Shedd Aquarium represent a large portion of the animals transferred in the recent rescue effort. Ten whales accepted by the Shedd Aquarium constitute 33.3% of the 30 whales moved from Marineland this summer. The loss of three belugas in less than a month illustrates the risks associated with relocating animals that have lived in captivity for extended periods.

The broader context involves the decline of the Marineland facility and the regulatory framework governing marine mammals. Provincial government data indicates that 20 whales died at Marineland since 2019, prompting the Canadian government to approve an agreement to move its last captive whales to avoid euthanasia. The Shedd Aquarium acknowledged these pre-existing vulnerabilities, noting that outcomes for individual animals could not be guaranteed despite intensive monitoring and care protocols.

Timeline

On 2026-09-21, the Shedd Aquarium notified NOAA Fisheries of Osiris’s death on Monday. On 2026-09-21, caretakers noticed sudden changes in Osiris's behavior and breathing patterns on the morning of her death. On 2026-09-21, Osiris was moved to the medical habitat, but her condition declined rapidly and she died despite lifesaving efforts.

What's New

A fourth whale that was moved out of Marineland in July has died after struggling with its health since arriving at her new home in Chicago, Shedd Aquarium said Monday. Research titled "Diel patterns in underwater sounds produced by beluga whales and Pacific white-sided dolphins at John G. Shedd Aquarium" was published in 2005 in The Journal of the Acoustical Society of America. A study titled "Growth and maturity of belugas (Delphinapterus leucas) in Cumberland Sound, Canada, and in captivity: evidence for two growth layer groups (GLGs) per year in teeth" was published in 2023 in The journal of cetacean research and management.

Special issue. Shedd Aquarium is a public aquarium in Chicago, Illinois, United States.