Question
I didn't know why my goldfish were disappearing from my pond but suspected racoons. I installed a net over it then noticed the garter snakes sunning themselves on the rocks and swimming in the pond. The poor fish just seem to be healthy and growing when they disappear. Please tell me there is something I can do to prevent the snakes from visiting in the water. Removing the rocks is not an option.
I love to watch the fish but am very reluctant to replace them if they will be used as snake food.
Thank you in advance for your advice.
Denice

Answer
Garter snakes can eat fish but usually aren't that great at it.  In my pond, when I see them, they only stay a day or two and then move on.  Are you sure you have garter snakes by the pond?  If they are instead water snakes, they will stick around and eat all the fish before moving on.  How big are the snakes?  How many?  A finer net can keep out larger snakes (but would also trap any already in the pond in the pond).  Aside from removing the snakes' cover (rocks and plants), there's not much else you can do aside from try to catch them and move them to another location.  Some "pest" companies might catch snakes for you but may just kill them so you'd have to ask.  I've never had the garter (or black rat) snakes stick around for long at my pond but some people have larger problems with snakes eating fish.  I hope things work out!

I have some snake photos and scant information at http://www.fishpondinfo.com/pmamm.htm
and http://www.fishpondinfo.com/animals/snake.htm