Great Blue Heron are majestic, beautiful birds with a healthy appetite. Koi ponds are like the proverbial “fish in a barrel” to a heron. A pond owner’s worst nightmare is finding missing koi that have been raised, become part of the family and are worth in some cases, thousands of dollars. A single heron can decimate a koi pond in short order.
So what is a pond owner to do? There are a range of solutions to prevent this tragedy.
First is pond design. If you are planning a pond make sure you have plenty of depth and adequate rock cover so your fish can evade the heron.
In most cases, we are beyond the design stage, so how do you retro-fit your pond to humanely deter these hungry predators?
One method is using pond netting. Netting rests on the surface of the pond and heron can not break through to attack the fish. This is a popular option, but restricts easy feeding and viewing.
Another approach is the use of Heron Decoys. Heron are very territorial and hunt on their own, so if a heron observes another hunting Heron, they will move on to easier pickings. Be sure to move the decoy on a regular basis and avoid using one during mating season, as it will attract heron between March and May in the US.
If you like technology, you can use a motion activated sprinkler. Position the device so that it covers the surface area of your pond. When a Heron visits your pond the sensor picks up the movement and emits a short burst of water that frightens the Heron enough to move on to a more serene environment. This tool works great for other fish predators like cats and raccoons.
Keep your fish safe with effective and humane predator control.