@Neil chace Captive, I guess - or at least actively managed. The pond is one of multiple on campus that the zoo uses to propagate Desert Pupfish (Cyprinodon macularius) for release into other water sources in the Salton Sea area. The initial population collapsed after the pond was overtaken by cattails and goldfish; it was restocked with a rescued wild population from elsewhere after the pond was cleaned up a couple years ago.
@Coelacanth18 That's awesome. Pupfish are some of my favorite fish so I'm glad to see there are some zoos doing great work with them! Even more reasons to want to visit The Living Desert one day (unfortunately no time soon, seeing as that's about as far away from me you can get in the continental US).