None.
♂ Gavryusha (transfer ≤ 2018-Jan)
On December 23rd, 2017 it was announced that Sochi had acquired a walrus pup to replace their bull Gavryusha, who had been sold to Weihai Sea World and was scheduled for transfer to China. I have yet to find visual confirmation of this animal or learn additional information about it, and at this point can only assume that Sochi no longer houses walruses.