Notice any fish disappearing lately? While herons are present year-round, water gardeners notice the challenges they bring to the pond in spring and early summer when herons feed their young.

An adult heron needs about 13 ounces of food daily, which is equivalent to three 6" koi. If herons find an easy source of food (i.e. colorful fish in a shallow pond), they'll return on several consecutive days. They can quickly decimate your fish population.

They're generally shy birds who typically visit early in the morning or in the evening, when everything is quiet.

Prevent herons from attacking your fish with these simple precautions. If you do lose some fish, don't resort to harming or killing the herons; they are a protected species.

Netting: The most effective deterrent for herons is to suspend a net 6"-12" above the pond surface. Make sure the net is taut and cannot fall into the pond if the heron tried to land on it and spear the fish through it.

Heron Scarers: Some work on a "trip-wire" basis, producing a loud noise while others use a sound inaudible to the human ear. Others sense the presence of heron using infrared detection, and scare them away by spraying a high-pressure jet of water.

Plastic Herons: Based on the principle that herons are territorial and don't feed close to one another, artificial plastic herons are popular. Unfortunately, they aren't effective year-round. In late winter and early spring, herons' search for a mate may actually attract more herons to your pond.

Pond Design: Dense growths of tall marginal plants or shrubs around the pond will limit the herons' access to the water. Ensuring the pond side is steep and the water is 8"-12" below the edge of the pond also helps since the heron will not be able to reach the fish.