Trails said - "Bill will the goldfish over populate the pond? Can the offspring be consumed by 3-5 inch BG? or a 12" cc?"
Goldfish, similar to numerous other fish species, can overpopulate a pond if the ratio of predator and prey is not balanced for that particular combination of fishes. Goldfish have many varieties and the number of eggs per female will vary depending mostly on body size of each female. A web search should provide additional information on fecundity of various goldfish varieties.
Goldfish are scatter spawners and eggs are adhesive. Parents and other goldfish will eat the eggs it they can locate them. Hatchlings will be small (1/4") and vulnerable to numerous forms of predation as they grow. The most colorful ones and those with excessive finage will likely get eaten first. BG at 3" to 5" will eat some of the hatchlings up to the point when the goldfish get 1/2" to 3/4" long. Then other larger predatory fishes will prey on the YOY goldfish. The more female goldfish you have in the pond the more likely you will have some recruitment of young goldfish. As I mentioned earlier the more drab colored ones and regular fined shaped faster swimmers will most likely be the ones to survive to become adults. For every bright colored new goldfish you observe there will probably be an additional 10 drab ones. The amount of cover-refuge areas and number and type of predators will be the main factors that will determine survial success of new goldfish.
