You could always cage them, feed them well and release them in a few months when they are larger.
I've got some in a cage now and they are eating 2# of food a day...... 1# in the am, 1# in the pm.
I had to make a larger feed ring (3" PVC) and put a 6" "skirt" of fine cage netting on it to keep the feed inside the cage.
I have some now that are about 9" long but their mouths are only about 1" gape.

When the feed hits the water it's like a school of piranhas.