I recently obtained a piece of land with a couple natural ponds that I would like to stock. I am having trouble determining what fish will survive here. The area is zone 6B but I don't know what that means for the water temperature. The ponds are quite large (roughly 15' by 30') with an average depth of 2'-3'. It does seem to get cold but there were was a goldfish population added some 20 years ago and has survived the winters so it can't be that inhospitable. I am interested in adding mosquitofish, killifish, orfe, and sturgeon (like one, I am aware of how large they get). I am open to any suggestions. Has anyone had any success with other fish?