If an aquarium has agreed to no longer taking wild caught dolphins, how is it any different from any one of the many western zoos with elderly apes and elephants brought in from wild sources?
There are several differences between Eastern aquariums with drive-hunt dolphins and Western zoos with aging, wild-caught wildlife.
First, there is the question of transparency: I'd assume that there was less information on capture methods available to zoos four, five, or six decades ago. However, the brutality of drive-hunts is well-known.
Second, there is the difference (in some cases) of monetary drive. At my local zoo, our three African Elephant cows are circus retirees. They were originally bought (In Zimbabwe, I believe), as cull calves, by the circus. Indeed, once I began reading into animal histories, I was astonished at just how many zoo animals were, at one point, kept in circuses or as pets. Of course this is not the situation for all "wild-caught" zoo animals, but those zoos which house "second-hand" animals, so to speak, are not responsible for that animal's capture and, in most cases, did not support captures by accepting these animals. However, I do not know of a single aquarium whose drive-hunt dolphins have all been acquired because the aquarium offered asylum to an aquarium which happened to be closing. On the contrary, Eastern aquariums bought approximately 80 dolphins directly from the drive hunt at Taiji just this past September. This means that the aquariums directly supported the capture.
But both these points seem unimportant, though, when one considers that some Western aquariums have only just decided to end buying wild-caught dolphins. Meanwhile, wild-caught great apes have not been bought by Western zoos since CITES regulations were enacted in 1975, and I believe that imports of wild-caught wildlife ebbed for a decade or two prior. Since then, very few wild-caught animals have made their way to western zoos. A striking exemption to this trend is that of the Swazi Eleven, eleven African Elephants that were captured in Swaziland in 2003 as part of a population control program. The eleven elephants were bought by the Lowry Park and San Diego Zoos for $12,000 each - hardly a fair trade. The act was extremely controversial, with many taking offense to the fact that wild animals were being captured for display in American zoos. I too was concerned - concerned that American zoos were doing business with a less than democratic country; concerned that Swaziland would manage their elephants for overpopulation so that they could profit from them; concerned that the elephants may be killed or shipped to substandard zoos or circuses if Lowry and San Diego did not take them; concerned that the elephants were going to locations with mediocre elephant habitats. There were many different issued to consider in the Swazi Eleven case. But no animals were killed in this event, much unlike the Taiji slaughter. Considering this, and the fact there is no reason to bring the cetaceans of the pacific, there is ample reason to put greater blame on aquariums with drive-hunt dolphins than zoos with old gorillas.
I hope that explains my position! I must say, I'm honestly surprised that people are actually claiming that there is no difference between the Bronx Zoo and the Taiji Dolphinarium with regards to their animal-collection ethics...