Chimelong Ocean Kingdom
I was able to photo-identify fourteen individual animals as living at Chimelong in 2021, including a minimum of three bulls and four cows. This park houses the largest herd of walruses anywhere in the world, at nearly three times the size of the second largest groups.
Chimelong stated in April of 2015 that their walruses were between "1 and 3 years old".
The CITES Trade Database shows a single import of 19 or 22 walruses into China in 2014 -- it is likely that this was the initial herd purchased by Chimelong.