I am surprised they have not decimated your goldfish!
Once upon a time, the earth was still warm, we inherited a couple of red-eared sliders.
They enjoyed a meal of ground meat now and then, or heartily bit one’s digits, depending on the circumstance.
Fast forward a couple pf decades, we purchased same species of turtle. Her accomodations where more rustic. Sadly, she got away at some point, still sorely missed after a decade or so.
In the meantime some sort of native turtle thing showed up in the backyard, and promptly was placed in the kiddy pool and supplied with minnows from the local baitshop.
All I can say, those beasties are vicious!
But oh, so cool!
A couple of years ago, my dog found a box turtle in the yard “MOOOM!! LOOK!!! This rock has |LEGS!!!”
It seems like turtles can and do climb fences (because all my yards have been fenced in with chainlink) Who knew.
I am considering another go at turtles, but for now I have enough on my plate.