7 Ways to protect Pond Fish from Herons and other Predators

Now, don’t get me wrong. I think blue herons are beautiful creatures and their behavior is only natural of course. Their very nature is being predators. When they use your pond as a restaurant, it’s just their way to feed themselves and their young ones. Their conduct is in their genes, and I don’t think you’d have much luck trying to turn a heron into a vegetarian or a vegan. However, you will want to protect your pond fish from herons and other predators and keep them safe.

Garden ponds are usually quite small and compact compared to a heron’s natural hunting grounds such as big lakes or rivers. At the same time, they are comparatively well filled with fish. This is what makes ponds very attractive to them. Some herons even seem to use them as a kind of kindergarten for their offspring where they can teach them how to catch fish. Remember, hunting for fish is simply their natural behavior. They don’t bear a personal grudge against you!

Which, of course, is more than can be said for many sad pond owners, who’s fish have served as a buffet for herons or other predators. You invested a lot of time (and money) into building a pond, setting up all the necessary technical gadgets to keep it’s biological and chemical parameters in the right balance, and grafted some plants into your garden pond. And last, but by no means least, you added your fish.

Most people love their pond fish. They feed them, take good care of them, and love to watch them swim, jump, breed and hunt. Some fish, such as koi, can be trained to be hand-fed. Some even love to be petted. And some proud fish moms or dads even talk to their fish.

So it breaks their heart when they come back to their backyard pond one sunny morning, only to discover that half their fish are gone and the other half – instead of coming to the surface to be fed as usual – just keep hiding away in the depth of the water or under some big water plants.

If your fish are expensive, it’s also not only an emotional burden but an economic one as well. Certain kinds of Koi, for example, can cost hundreds or even thousands of Dollars. You don’t want to lose this sort of money just to fill the stomach of some straying bird of prey.

So, what can you do to keep your pond fish safe and the hungry beasts away?

Know thy enemy!

It’s always best to know who you are fighting with exactly to come up with the best possible defense. Usually, you’ll find some leftovers of what used to be a beautiful pond fish in the vicinity of your pond. If it looks as if it’s been cleanly cut into two halves by a blade, you can almost be certain this was the work of a heron’s sharp beak.
If it’s a carcass with bits of flesh torn away, it’s more likely a raccoon or a cat from the neighborhood.
Maybe you’ll find some footprints. The shape and size of the paws should give some clear indication which animal these belong to.

If you don’t find any useful evidence, you could put up cameras with motion sensors. With these, you might be able to get some mugshots of the nightly marauders who pillage your water feature.

So, how to protect Pond Fish from Herons?

Herons don’t dive into the water from the flight, as many seabirds do. Instead, they land on a waters banks and step into to the shallow waters on the edge. From there they catch the fish.
Cats can swim quite well, but most of them prefer to stay on land. So they pluck the fish from the edge of a pond as well.
Raccoons, on the other hand, are very talented swimmers and can stay in the water for hours.
Either way, all of them enter your garden pond from the edge. So this is your weakest spot and your main line of defense.

Protective Measures for your Garden Pond

1. Netting

One way to protect pond fish from herons is to put a net over it. You will need a net that’s large enough to cover the whole surface. In fact, it has to be slightly larger, so it overlaps the pond, and you can fixate the net in the ground, for example with some tent pegs. And the fabric should be thick enough, so it’s not chewed away by some strong teeth or cut to pieces by a sharp beak.
Pros:

• Covers the whole pond, so protects against water birds landing on your pond as well.
• Usually inexpensive (but this depends on the size of your pond, the larger the net, the more expensive it will be).

Cons:

• Not a pleasant sight. You want to enjoy the view of your pond and a net spoils this image considerably.
• Makes pond maintenance and feeding your pond fish more difficult. Every time you want to do some upkeep, you will have to remove the net and put it back in place afterward. And if the mesh width of your net is smaller than the food you give your fish, you will have to do the same for every feeding.
• Not advisable if you have one or more fish species which like to jump out of the water occasionally. The fish might get caught in the net and perish there.

2. Ordinary Fence

Another simple measure is to put a small fence around the pond. When I say small I mean it doesn’t have to be a fully fledged six ft high wall you might have around your backyard. But it needs to be tall enough, so smaller animals don’t just jump over it. You should be able to buy such small fences in your next gardening center. They are used to protect flower beds or vegetables and are either made of steel, plastic or wood. When you go for a green or brown colored fence, it will blend in more naturally with the trees and foliage in your garden. 
In order to stop herons marauding your pond, the fence needs to be quite near the water. If you leave too much ground between the barrier and the water, the heron will use this as a landing strip and still enter your pond from there.
Of course, this will make feeding your fish and doing maintenance tasks more tricky, so you should incorporate one or two gates into your surrounding fence.
Pros:

• Not only does a fence keep predators away from your garden pond. It also stops small children from falling in. So, not only your fish will be safe but – more importantly – your toddlers will be protected as well.

Cons:

• Like a net, a fence spoils the view onto your pond.
• Maintenance and feeding your fish will become more challenging.

3. Electric Fence

Usually, a regular fence will do. But if your unwanted visitors are very persistent, you may have to convince them with a bit more oomph. For obvious reasons, you shouldn’t use this when small children or pets are running about.

A raccoon on the hunt.

Also, as we are operating in the vicinity of water, you should keep the voltage at 24 V at max.
Pros:

• Electricity hinders animals from climbing over the fence so that you may choose a lower one.
• Will be more convincing to even the most tenacious predators.

Cons:

• Not suitable when you have small kids or other pets like rabbits, dogs or chicken.
• Will add to your electricity bill.

4. Fishing Line

A fishing line is a very cheap option and easy to install. Drive some stakes into the ground around your pond. Then take a strong fishing line and weave a kind of criss-cross pattern between the stakes.
Before installation, you should drill some holes at different heights into the stakes first. Then you can pull the fishing line through and fasten it with a knot. Connect some higher up holes with lower ones, so you don’t leave big gaps where a small animal can slip through.
Pros:

• Very cheap, easy installation.

Cons:

• Not the nicest sight.
Will make getting to your pond harder for you as well.

5. Blue Heron Decoy

If your pond has turned into a dining table for a heron, buying a heron statue and mounting it near your pond can be a solution. Herons are very territorial birds. They each have their own hunting ground and will usually keep away when they see another heron in your garden. Or, in this case, a mockup.

Herons aren’t stupid. When you just set up a heron dummy in your garden and leave it where it is, the heron (the real one) will notice that it’s not moving. It will come closer to see whether the other “bird” tries to fend it off. When there’s no reaction from its opponent, it will eventually land in your garden anyway.
So it’s necessary to move the heron decoy around every day or even twice a day.
Also, when it’s breeding season, your heron statue might suddenly not look threatening to its living comrades anymore. I’ve heard of several pond owners whose dummy herons became the romantic object of desire of a flirting heron.
Pros:

• A heron mockup doesn’t spoil the look of your garden pond.

Cons:

• Needs to be moved on a daily basis.
• During the breeding season, it might attract real blue herons instead of keeping them away.

6. Motion Activated Water Jet Sprinklers

These devices will spray bursts of water onto any intruder. Cats, pigeons, raccoons, or herons. The sprinklers have motion sensors, so they operate automatic. You connect them to your water tap with a hose pipe. You have to leave the tap turned on, but water will only be released when the sensors detect some motion.
Cheaper units work with batteries only, and they use quite a few. The better units have a solar panel and rechargeable batteries. You should also check whether you can adjust the sensitivity of the sensor and the strength of the water jet.
Pros:

• They scare away many different kinds of animals.
• They frighten the animals but don’t harm them.

Cons:

• They can’t differentiate between friend or foe. So your cats, dogs or even yourself may get wet occasionally.
• They need an open field to operate best. Not suitable for areas with dense vegetation.
• Won’t work in winter, when temperatures go below freezing point.

7. Pond Defender Discs

These items are available from several brands and are sold under different names. Basically, they are black plastic discs, which look similar to a spider web. They float in the water, and you connect them with one another with small twist ties or clips. This way you form a ring of discs around your pond’s inner edge. The idea is that while they float, they will dive down once an animal steps onto them. So they won’t be able to get to the water, as the discs will create a wobbly surface they can’t stand on.
Pros:

• Quite cheap.
• Very unobtrusive.

Cons:

• Due to the web like structure, they can collect a good deal of plant detritus. So you will have to clean them every now and then.

So, these are the seven different measures to protect pond fish from herons I promised in the headline. Hopefully, one of them works for you and suits your budget. Unfortunately you as pond owner have to find out the best method for your own personal circumstances.
Do you have any experiences with some of these methods? And which used to work for you and which didn’t? Do you have another method not mentioned here which works like a charm? Which steps do you take to protect pond fish from herons and other predators?
Let us know in the comments.