I hesitate to respond to this thread, but I think there are a couple of narrow, judgmental views voiced here. When a guy I know built his pond several years ago he wanted a few fish in there just to have something to look for and enjoy watching. He knew of a pond where heron liked to hang out so knew something was in there. Taking his cast-net one afternoon he caught a dozen or so fish several of them being comets.
Fast forward to the third year of his pond. Talking with a guy at the local nursery he casually mentioned he was filling in the plants around his pond and mentioned that there were frog eggs all over the place, but suspected the fish would probably take care of the tads. The nursery guy asked what kind of fish and my friend told him just common gold fish. He told my friend they were illegal in an outdoor pond in this state. Really? He had no idea! He did some research and discovered this was correct. So, here he is, in the morning a happy pond owner with a few goldfish and in the afternoon a criminal pond owner with a few goldfish. Once he knew the law he was in a quandary - does he destroy the fish? Catch them and return them to the original "illegal" pond? Try to sell them, or give them away? He elected to keep them for the time being. This was two years ago. If he gets busted with them he'll own up that he knew they were illegal. There may be a fine, and the "fish and feathers" may poison the pond, but they are just as likely to look the other way since his pond is so isolated from any other fresh water in this area. The argument is that goldfish eggs are sticky and may stick to the legs of a heron, duck, or any critter that may come in contact with them then transfer them to another body of water.
Now, before anyone suggests he should have checked it out before he put them in there, who in the world would have thought a few goldfish would be illegal in a small rural pond, especially since they were caught in a rural pond? As someone earlier said, we must be the only state in the union where they're illegal.