That cloud of black fish was almost certainly bullheads and they do spawn in ponds.
I remove everyone one that I catch.
I took out (3) yesterday and they now reside up on the bank under a nice pine tree.
In fact, my sister in law happily pointed out that she saw a little baby catfish. It was sunning itself on a rock in 3" of water. I moved towards it, and it shot off the rock.....right into the mouth of a 10" LMB. So sad.......NOT!
