Snakes Alive!

Plastic netting works keeping predators out. I put lettuce in the pond this
morning for the guys to munch on, upon returning from church I saw a piece
hung up in the lip of the puddle that goes to the lower pond and proceeded
to stick my hands down under the netting to get it loose. As I stood I saw
what made me holler for DH. Right where I was pulling the lettuce loose was
a big black snake caught in my netting (4-5 ft.) He was tangled up real
good. Took DH 30 min to cut him out and get him back in the woods. I said to
axe him, he came for lunch. My DH was compassionate telling me they eat mice
(my other cringe) we had to try to get him out (as the snake kept trying to
bite at him). Will these snakes eat my fish or will they dwell together?
Joann