I didn't even know a goldfish catch was a thing until last year when Anne posted photos of her daughter, Oren's friend Lyla, at one in a nearby wading pool at one of the local parks. This year she was sweet enough to give us the heads up as to when it was happening again and let us tag along for the fun. I didn't tell the boys anything about it ahead of time and secretly had a fish tank and all necessary accroutrements tucked away at home for when we got home with our catch.
So what happens is the local parks department lets about 400 goldfish loose into the park's (non-chlorinated) wading pool and the kids can wade in and catch them with their hands or tupperware containers and take them home. All three of my kids went absolutely nuts over this. It was a complete treat and they could not have had more fun if they tried. The boys caught about 14 total before giving most of them away to other kids. We ended up bringing home six of our own - Goldie, Red Hero, Thunderbolt, Dory and two named Fire.
It has been four days since the catch and despite our best preparation and care only Red Hero remains with us earth side. And that's why it's an annual event. Oh, the plight of a goldfish. Godspeed little fishy.