I have seen it done in Australia.
We mainly have salt pools so they probably stop topping up for a while and it weakens/dilutes.
They then put trout in the pool and feed them up over winter and have a BBQ with fresh caught trout before summer heats up.
Trout can be raised in a swimming pool though it’s best only to use an above-ground pool for seasonal farming rather than a permanent, four-season environment. Above-ground pools are often used in tropical locations like Hawaii or the Southern US mainland.
Raising Trout at Home (Homestead Farming for Food Independence) - ruggedoutdoorsguide.com