Since the acclaimed documentary "Blackfish" was released in 2013, concerns have increased regarding dolphins and killer whales being kept in captivity. Indeed, SeaWorld in particular has attempted to justify keeping marine mammals in its amusement parks amid a huge public backlash.
According to data reported by National Geographic, Japan has an estimated 543 dolphins and killer whales in captivity
, the most of any country worldwide. The US isn't too far behind with an estimated 529 while China
rounds off the top three with 294. 296 dolphins and killer whales are estimated to be in captivity in amusement parks across Europe.