Hmmm...disposable pond, what to put in a disposable pond......
Sometimes the best way to answer a complex question is from the simplest angle. The only fish that I know of which I would consider disposable is the justly maligned green sunfish. Therefore, I would stock disposable green sunfish in my disposable pond.
Actually, in thinking about it, this would help smooth out some of the yings and yangs of pondmeistering in a dry climate. For example, one's usual rejoicing at the lifegiving moisture provided by the heavens would be tempered by the knowledge that it was sustaining the lives of the GSF. And the worrying and gnashing of teeth caused by serious dry spells would be mitigated by the assurance that the GSF were finally meeting their dessicated end.
