While Harbor Porpoise may be fairly common in US waters, I'm not sure where the idea of "it might be fairly easy to get some rescues" comes from, as if that were the case there would be a population of them already in captivity. Why would you expect that to change just because a zoo/aquarium is now interested in housing some?
I hate to say this, but, as someone pointed out above, the reason you probably don’t see harbor porpoise rescues very often is a) people don’t bother trying because they are hesitant to take the risk and expend the resources on a less well studied species that’s in poor health already, and b) even if they do, the effort fails. Rescuing an animal is often a zero sum game - you either save a life or you don’t, and sometimes it’s simply too far gone to even try to help. I know for a fact that the species has shown up a few times in my local area (SeaWorld San Diego) but based on them not being on exhibit, those efforts came to naught. But if a zoo had space for a rescue that survived, it could become an option. So I suppose I ought to revise my statement to “it could be potentially easy to acquire some rescues, should the need arise and should a facility in the local area be willing to take on the initial task.”
A more generalized rescued cetacean exhibit space in place of an ongoing captive population/breeding program is imo a very interesting idea, but not for Minnesota which is much too far from water to actually rescue animals themselves.
I only brought up the harbors because they’re interesting, and I think it could be a worthwhile endeavor to more actively try to rescue whatever sick individuals are found. This is a hot takes thread after all, we’re all spitballing here
If you ever read Brooke Besesen's book on the vaquita, she devotes a fair bit of space to discussing the differences between dolphins and porpoises in managed care, which goes part of the way to explaining the ill-fated attempt to capture vaquita for a rescue project.
I’ve not read that particular book, but I am fairly intimately familiar with the vaquita species survival attempt. I’ve actually had the chance to hear a lecture from and speak with one of the main scientists involved in the effort back in the late 2010s, and cited his paper in some of my college research. It was a disastrous attempt to put it mildly, and tragic that it failed, but he did mention to me that the scientists theorized the vaquita as a species was
particularly susceptible to stress, even more so than all other porpoises. I wager harbors are, while still more difficult than dolphins, more manageable as Vancouver did very well with their rescues for a good few years, and rescuing in general is extremely high stress for the animals. The Yangtze finless porpoise, an endangered species itself, has done very well in captivity in China, and even had captive bred individuals released into the wild (if the government reports are to be believed). Definitely will check the book out though - sounds fascinating!
