Goldfish are like catfish, they can survive in murky/ muddy water without fresh water or a lot of oxygen coming in. They do need a little space though. Being too packed in some would die off just because the pack of them would use up too much oxygen too fast. Some would survive, if they could.

I wonder if goldfish could survive this far north in a bigger and deeper lake versus a backyard pond? Probably mess up the ecosystem for other fish. Interesting to think about.

What do you know about goldfish, without stopping to look them up online, or elsewhere?