So I was heron free for numerous years with my pond since I built it 9 years back. Then one year they found it and I lost a few wakin goldfish. I did the fishing line fence but with a small kid around ... it wasn't feasible in the long term because of the bridge. A few years later one came and took more. I hate those birds!
So this year.. besides buying replacement koi... I found out that there is a heron rookery a handful of miles away... so I decided to bite the bullet and do the netting thing. It's nice to not have to worry about a heron visit anymore.
I just complete it recently and it's working out nicely. Since I have hard lined/modern pond against my pergola... doing the straight edged frame worked out. It's built from black anodized aluminum tubing, which are jointed together with plastic joints, and the netting is attached to the underside with stainless screws.
The smaller square portion to the right of the bridge just lifts off if needed, while the left portion is hinged into two sections. That right section lifts up like a trap door in case I need to net something or access the water. Being aluminum... it all weighs 10 lbs. The frogs can get in and out fine on the sides..... but if they do get to the top... it is kinda sad to see a big old bull from hopping all around trying to find the edge.