Overall, an interesting heron solution that may be worth a try in smaller ponds, but we would only really recommend this method when all other deterrents have failed.

Often pond owners attribute their fish dying over winter to the cold, but it’s more commonly caused by buildup of sludge (waste) which has been left to decompose and build to dangerous levels. During this process, oxygen levels in the pond drop, and harmful ammonia and nitrite levels rise, which places a huge amount of stress on pond fish. A second option to stop herons from eating pond fish is to try to install pond fencing or wire around the perimeter of the pond. If you can stop herons from getting to the sides of the pond, they won’t be able to effectively hunt for fish. Although sometimes more effective than pond netting, fencing is more noticeable and harder to maintain. Using thin wiring for fencing is a popular middle-ground, as it’s strong enough to stop predators getting near the water but small enough to not be visually distracting. Even though they can be a nuisance to fish keepers and pond owners, both types of common heron are protected species. Grey herons are protected under the UK Wildlife and Countryside Act 1981, and killing herons can incur hefty fines and even a prison sentence. Likewise, blue herons are also protected in the United States, including their nests and breeding grounds, by both state and federal laws. These laws make it illegal to kill or capture the birds without a legal permit. Are herons to blame for missing fish? Generally speaking, purchasing pond netting with small/medium (3/8 – 1/2 inch) size mesh holes will provide protection from both leaves and predators effectively. This is the best size to combat both debris and predators, and is the most common with most pond netting manufacturers. Fish shelters are a cost-effective and easy way to create a durable cover system on the pond floor, giving both koi and goldfish somewhere to retreat and de-stress. They won’t scare away a heron, but they allow your fish a much better chance of not becoming easy heron food.Another type of automated sensor device is one that emits a sudden sound to scare animals away. Automatic sound repellents are useful for getting rid of flighty animals and work well against all but the most stubborn of herons. They usually come in two forms – one being a normal sound recording, and the other a low-pitched ultrasound device. The lightweight design means the pond protectors float on the surface of the water, creating a protective layer. The first which just emits a loud noise works well for most pests, especially if the recording is something the animal is naturally wary about, such as gunshots or barking noises. The downside of this type of device is that they’re activated by motion sensors, so will go off whenever anything larger passes through the sensor. If you have pets or regular garden birds, this could prove quite frustrating if the noise keeps going off. If your fish pond is close to surrounding foliage, such as trees or bushes, or if you have predatory birds or cats in the area, then installing a pond net is highly recommended.

If you have a pond with no natural cover, especially if the pond is shallow, we recommend a fish shelter as this will make hunting much harder for predators. As they won’t directly deter herons, fish shelters are best mixed with other deterrents, such as pond netting, decoys, or automatic repellers (water or sound). In terms of deterring snakes, I agree, that’s a tough one. Since they like to hide away in nooks and crannies very close to water, closing off as many hiding spots as possible around the pond may help prevent them from hanging around, but I doubt this would keep them away all together. Your advise of simply keeping a close eye on your pond everyday, as well as monitoring fish for injuries and unusual behaviour, is likely the best way in most situations to determine if a predator is present. Reply

Pond netting works well in both floating and raised forms, and will help stop herons from entering the water so long as the netting is secured and maintained properly.