MIZORE AND IMPROPER CONDITIONS FOR CAPTIVE PINNIPEDS

Tavishi

The ringed seals at Osaka Aquarium have long captured the attention of the internet. Take Yuki, the most famous ringed seal from there. Yuki's likeness has been captured in a viral seal plush:

Then there's Arare, a ringed seal who is notably also the mother of Mizore.

On April 1st, 2021, Arare gave birth to Mizore. However, due to birth complications, later that day, Mizore was found with low blood sugar and hypothermia. As a result, the aquarium handled maternal care itself.

In October 2023, Mizore was moved from Osaka Aquarium to Otaru Aquarium to be a part of their breeding program there. Personally, I found the decision a little strange, as he has a number of years to go before reaching sexual maturity. On June 19th, 2024, Mizore passed away due to "unknown causes". However, pinniped enthusiasts around the globe are suspicious that his tragic passing may have been related to the poor standards of care at Otaru Aquarium. Compared to Mizore's enclosure at Osaka Aquarium, his enclosure at Otaru was much less enriching. Furthermore, he was kept without companions, and many reported he engaged very little with staff.

According to the European Association of Zoos and Aquariums, two things crucial to any phocid enclosure is a well designed pool and a deck with plenty of haul out space. While Mizore's enclosure contained both of these requirements, it was the bare minimum that could be done. Ideally, Mizore's haul out space would be larger, and far more enriching. Furthermore, it is generally advised that darker and more natural colors be used to paint pinniped enclosures in general, whereas Mizore's enclosure at Otaru was bright blue. Most important to this was the lack of enrichment within the enclosure, which the AZEA cites as potentially more important than the actual space within an enclosure. Mizore lacked other seal companions at Otaru. Back at Osaka, Mizore lived with three other seals. But at Otaru? Mizore was entirely on his own. The EAZA advises pinnipeds be kept with and be allowed to interact with others at the risk of isolation causing stress. Some of the biggest signs of stress include chewing at one's own fins, anorexic behaviors, aggression, repetitive behaviors, and drawing away from social interaction. I cannot for sure confirm or deny the presence of all of these behaviors, as I am not someone who was regularly visiting Mizore at Otaru Aquarium. However, the aquarium itself reported that in the weeks preceding his passing, Mizore's appetite lessened. Other visitors have reported on the internet in the past few months that Mizore has seemed much less energetic, repetitive, and utterly depressed. We can't entirely verify these claims, but it remains that Mizore passed far too soon. Otaru Aquarium is also not exactly known for its standards of care, with a number of pinniped deaths under their care: like Fuuta (2023), Upaupa (2022), Fubuki (2021), and Paopao (2020). Most notably, the cause of death for Fuuta presented similarly to Mizore: cause unknown. No statements can be made for sure about whether or not the stress and lack of enrichment was the cause of Mizore's death, which is important to keep in mind. There is still nuance to the situation. We lack a lot of knowledge about what is going on behind the scenes. Most of what can be said is merely speculation. But it certainly wouldn't be the first marine mammal death in captivity because of improper care.

Typically, it is cetaceans we see this with. If you've ever watched the film Blackfish, you can understand how much of an issue stress on captive marine mammals is. In fact, orcas consistently die well before their lifespan in captivity.

Kotar, who died at 17.

Kandu V, who died at 14.

Ula, who died at 2 years old.

Kyara, who died at only 3 months. The list goes on of mistreated orcas whose deaths were entirely preventable.

The death of Mizore was unmistakeably a horrible loss. Mizore died far too young, and I hope that some answers are found. And I sincerely pray that however he died, his last moments were at peace.