I have a 4 X 8 drainage pool in my yard in which I put a dozen goldfish about four years ago. Over time they kept disappearing until now there is only one left. He's grown from about two inches to about eight. What you are seeing along with the fish are reflections from the surrounding trees and sky.
Lovely reflections in the pond. OK, we've had hawk and heron, how about grass snake? We had a grass snake in our garden pond last year and our fish also slowly disappeared! We have replenished now and there has been no sign of the snake again so fingers crossed!
