The crowd did; the whales obliged. And as a few whales slid out onto a white platform, in front of a massive LED screen in the shape of an orca fluke, the performance came to its slickly produced end.

With that, after a half-century of tail splashes and orca acrobatics, the marine mammal park closed its final Shamu show.

The business of killer whale entertainment is a half-century old. It has changed dramatically since its formation. It is now illegal, under the Marine Mammal Protection Act, to import or display orcas without first passing expert review and a 30-day public comment period, after which the National Oceanic and Atmospheric Administration may issue a permit.