Earlier quoted context omitted.
From TFA: "The bill has exceptions: cetaceans can be kept in captivity if they're receiving care or rehabilitation after an injury, or for scientific research."
The scientific research loophole seems like a pretty big one.
The aquarium argued it was a pure research program, and it was a legit research program that had been going on for decades at least, I think. But public opinion swung against them and they made arrangements to end their program. Mostly their position was untenable because the aquarium supports itself with visitor ticket prices and donations, and the simple sight of belugas doing neurotic laps in a relatively tiny tank was enough to cause ticket sales to drop once it was publicized that their living conditions were inhumane.