There's a more direct impact, too: The Vancouver Aquarium houses animals which have been rescued and nursed back to health after various injuries. This ban will result in many of those animals being left to die instead.
I think that is hyperbole. They are only banning the whales, not all the other animals that are helped by the aquarium. I was at the aquarium this last summer. There's much more to it than the beluga whales. Sure some people will choose not to go once the whales are gone, but there's still tons of other things to see.