Keeping Pond Fish Safe From Predators – The Follow Up

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Well it was quite a response.

Of all the articles we’ve done so far, the one about keeping pond fish safe from predators really generated a lot of responses from our readers.

This doesn’t surprise me really. Pond owners are helpful, caring people, and many know what it’s like to find a heron, raccoon, cat, or other critter looking for fish for dinner. I guess that’s why I’ve never seen so many suggestions or tips come in via email regarding how to keep them all at bay.

Suggestions included motion activated lights, decoys, guard dogs, border wires, netting, and more. In my book, nearly anything goes as long as it’s legal and doesn’t harm anything.

So in the spirit of trying to help other pond owners from this plague, if you have a tip or technique for dealing with predator problems around your pond, please share it here. You can do so by using the comment section below. That way everyone can learn as we go along.

We all appreciate it!

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21 thoughts on “Keeping Pond Fish Safe From Predators – The Follow Up”

  1. Knock on wood, my two geese decoys have kept the herons away for two years now, though they haven’t done what they were intended to do which was bring in real geese to my pond! I also created a lot of hiding places out of smaller boulders for the fish when I built the pond which not only keeps them safe from predators, but gives them a place to escape the hot sun in the summer, and to take refuge through the winter freeze!

  2. I have a hundred gallon pond in my back yard, I put a 3 foot fence 5 feet away from pond around the pond. Then I got electric fence wire and put that 5 inches above the wire fence. I have a electric fence gate handle on it so I can go in to feed and enjoy my fish.No cats or dogs or any 4 legged animal goes near my fence. I put snake away around the edge of the fence to keep snakes out.

  3. The thing that works the absolute best to deter predators from eating your fish is the “deep pond” idea.
    One blue heron showed up, but couldn’t stand up in my 3’6′ deep pond that has straight sides(other than the first ledge that is 12 inches wide and 12 inches deep).
    Even the black bear that showed up, gave up after 3 failed attempts to get my 34 inch koi(although he did knock quite a few things over).
    I planned my pond with the predator factor in mind, as well as the freeze factor we have in Pennsylvania.
    Electric fences(2 strands 4 inches apart)with the lowest strand about 3 to 4 inches above ground level(and on a timer) will deter most raccoons.
    Most anything that moves, makes noise, or sprays water will deter most predators.
    As far as motion lights, predators will be frightened at first, but after a while they become accustomed to it and actually use the light to locate the fish.(fish are drawn to light and WILL surface after a few seconds, making them easy prey).
    Except bears(any of the above will make them mad). You DON”T want a disgruntled bear in your yard!
    Deep, Deep, Deep, is the best answer.
    Good Luck from Don in Pa. 7 year pond owner, and I raised my fish from 4 inch babies(4 generations in my pond now).

  4. I had racoons raiding my pond at night. I know this sounds silly but… I put a motion alarm (with sound) in my back yard by my pond. Then I hooked up a baby monitor next to it (in an old mailbox to protect it from moisture). I put the other end of the baby monitor in my room. Everytime I heard the sound go off I looked outside my bedroom window with a flashlight. If it was just the wind or something I wouldn’t go back to sleep, but if it was a critter I would chase it off! I know, there had to be an easier way but you have to admit it’s original.

  5. My most effective protection was to string fishing line and some thin copper wire back and forth about ten feet above the pond-this stopped the osprey attacks cold and made my pond a place for heron to get “serious nervous conditions” As they fly in beside the pond and walk in (under the lines) leaving can be very scary=they’ll forget about the lines and be snagged,,I watched one that had to roost on a nearby rooftop and get control over the shakes before he could go home..heh. heh. all my guys are over 2feet long now so I took all the line dn. last spring.

  6. Well, I must say that the idea of putting an electric fence has promise!! But I have found
    putting a bird net over the top making a very
    tight fit more like a springy efect the bird can’t get to my koi and the dogs love to watch the fish. Just an idea for some of you to try.// total cost is 5.00 at home depot.

  7. When I first started my pond 4-1/2 years ago I never thought about having fish. We mostly wanted it for the 20 foot high waterfall but then we started to get mosquito larvae and string algae in the pond at the bottom of the waterfall. It was then we decided to get some Koi. I bought 4 to begin with for our 3,000 gallon pond. They grew quite large in the first year, must have been from all those mosquito larvae, from about 2 inches to 6 inches. One day I was looking out the window and noticed something different but I couldn’t tell what it was. I knew somthing was wrong but I couldn’t tell what, and then it moved. Not much, but enough to discern it was a Giant Blue Heron. I ran out and chased it off and then noticed fish scales on the concrete decking and bridge around the pond. He got one of my Koi. The other three stayed down in the deep part for months after that. He came back for a snack several times after that but I managed to chase him off and the three remaining fish stayed deep. After a little research I decided to net the pond. I found some very thin 4″ square sun resistant netting online and stretched it over the pond in two sections either side of the bridge that goes over the pond. I used Gorilla glue to glue small wooden (oak) blocks about 1″ x 1″ x 1/2″ to the rocks around the pond at strategic locations. I then screwed small brass hooks into the blocks which became my anchoring points for the netting. I cut the excess netting after securing it to the hooks because the pond is very irregular. We have a fenced in 1/2 acre yard so bears and other large creatures are not a problem. We have had visits from some more herons and egrets but the netting deters them and they soon fly away. I’ve added some more Koi but the original three decided to have babies so now I have almost 40 of them and they are all growing quite large. The original three are now almost a foot long and the others are not to far behind. The netting was relatively inexpensive and only took a couple of hours to install. You have to wait a day for the Gorilla glue to set up before stretching the net, otherwise the blocks pop off the rocks. If you do this use a little strapping tape to hold them in place so they don’t slide of the rocks before setting up. My pond was already set up before I knew about predators so I couldn’t make it any deeper. It is only deep in the middle of one part, about 4 feet. If the fish wander into any other parts of the pond they become easy pickings for a heron or some other smart fisherman. The netting solved the problem and unless you get really close to the pond you don’t see it. To me the netting was the easiest answer for a long term solution. It’s worked for 4 years and looks like it will last a lot more. There is little or no maintenance and I can leave the pond during the day knowing the fish are safe. I’ve often wondered if I would come some day and find a heron or some other critter tangled up in the net possibly drowned, but they seem to know to keep away, which is fine by me and my fish.

  8. Only once have I had a heron which is unusualy for a pond in the center of a large city…early in the morning it was standing in shallow water, but did not get any fish before I frightened it away…has never returned.
    The worst are racoons – they are very destructive and knock everything over and will eat plants as well. I have a 2ft. high, light wire fence which diverts them to the higher parts of the pond where they cannot get to water level. Also, a plant called Jackman Blue, which produces an oily essence which animals in general do not like. As well, if you have the room a rough path, about 18″ wide or rough ground eg. lava rocks etc., racoons do not like walking on rough surface. Two other tricks – plastic 500ml bottles of Javel water, buried in the ground with their tops punctured will deter them. Finally, mouse traps without bait which attracts animals. When a racoon steps on one, they don’t return so quickly.
    Skunks like to drink and leave – don’t go near them. Groundhogs, cats etc..the same.
    Hope this helps.

  9. Our yard is fenced, so 4-legged critters are not a problem. However, our pond (~17×24 with an 18′, 4 level stream) is right out in the open. There are no overhanging branches to hide it from the overhead onslaught. We have lost some fish to the one or more Great Blues that frequent our area. (There’s a river nearby)
    In addition to having a “scare crow”, we’ve placed monofilament along the edges and have a decoy heron that we move around periodically.
    Our most recent addition has been a large, colorful beach ball that “roams” around the pond with the breeze. The monofilament keeps it in the pond, and the fairly constant motion seems to discourage the featherd creatures from visiting.
    These measures seem to have discouraged the heron(s) for the past 2 years and we’ve not lost any more fish. The mouse traps seem like a good idea and we may add those in a few strategic location. (Thanks, mrosman, for that suggestion.)

  10. A device named “Scarecrow” was recommended to me. Basically, it is a ratcheting type sprinkler head attached to a battery (9 volt) powered motion sensor. It senses both heat and motion from the intruder. It does require a hose or direct connect water supply attached to the device. When a predator passes in the field of view (180 to 240 degrees?) it activates sending the water spray in an arch and moves back and forth three or four times. The distance, sensitivity and spray pattern can be adjusted.

    The manufacturer is Contec Electronics. It ususally sells for $60 to $70 and can be purchased through or other online retailers, or through a pond maintenance company.

    The only caution is making sure the battery is kept fresh.

  11. We had a big problem with a giant Blue Heron, when we first built the pond. Living in the Virgin Islands buying fish is not cheap, This Heron ate over 300.00 in fish within a couple of days.

    What finally worked was taking monofilament fishing line and stringing it from North to South and East to West about a foot and half grid pattern. Heron’s unlike Ducks etc.. do not land into the pond but, walk in. This causes them to trip and eventually give up.

  12. I designed my pond (5000g) with a plant ledge around 3/4 of perimeter, 1-1 1/2 feet deep and a straight drop from there. I was thinking about skunks and raccoons, not heron. Unfortunately in the second year a heron discovered my pond, and was relentless.If I chased him,he would sit in a tree,and as soon as I returned to the house,he was back in the pond. I tried opening the door for my Doberman,
    a trip wire, and a motion activated scarecrow. The scarecrow lasted only a few days, I came home from work to find it by the pond in several pieces,obviously the victim of a violent bird attack. The solution came with a severe algae bloom…I put up a sun shade(Coolaroo) to reduce the amount of light. The bird returned,happily walking along the plant ledge…I opened the door for the Doberman…the look on that bird’s face was priceless as the dog was airborn off the deck heading for the pond, and the heron realized it couldn’t just take off from the ledge because of the shade. It first had to climb out of the pond,slowing it’s escape. It’s been 3 years and I haven’t seen it since. The bird wasn’t harmed, the dog had fun, and my fish are safe.

  13. I have had a 3,000 gal. pond that I built 6 years ago. It is 4 ft in the center. I have not had any preditor except a king fisher, which is fine because he just eats the goldfish. My koi are 5 years old and too big for him. The best thing I have found is a tall fence ours is 7 ft around the backyard and a dog. My little border collie protects the yard. We have been thinking about electrifying the fence to keep the ground squirrels out, one made a hole in my liner in the stream. Enjoy your articles!

  14. No one has mentioned snakes. I had 4 fish just disappear …. and then I saw the snake…go in, and then out. I put out mothballs and haven’t seen any since, but of course they could still be around. No mysterious disappearance since, and that was 2 years ago. About a year ago, I rebuilt. I lost 2 fish…about 3 weeks after purchase. One was just gone …the other I found in the skimmer net…with a big gash. Everyone said heron…but I have straight sides, no shelves and 3.5 to 4. foot deep. I covered with net after that and have had no more loss of fish, But I really wish I could take the netting off. About what size do the fish need to be to finally be safe?

    Does anyone have any other suggestions for the snakes?

  15. I have a Giant Blu Heron that discovered my pond 4 years ago. He stole two of my Koi and comes back on occasion for more. I went and bought a net and placed it over the pond and use fasteners to poke in the ground to keep it secure. The Heron does come around on occasion, and I know when he has visited even though I haven’t seen him, because the net will be laying on top of the water still fastened. He can’t get to the fish with the net there, and since my two fish were stolen and eaten, the rest of my fish have been safe. A net works for me and is a very inexpensive fix.

  16. A few comments:
    1. to the question of how harge the koi must get to be “safe” from Herons. The fact is that a heron will attack any size koi with results from ranging from gashes, loss of fins, blinding, etc.
    2. the water “scarecrow” has proven effective against most herons. Once in a long while, we’ll get an older, wiser one who simply will not be deterred by the water and noise. Anytime we determine that we are not scaring off the visitors — either by observation or missing fish, I place 10 mousetraps around the pond (5,000 gal) in strategic locations where predators will attempt entry. (Yes, I had a so called koi pond expert design & build my pond).

    The noise and motion (they jump into the air) of a mouse trap snapping shut is a very effective deterent. The visitor doesn’t have to actually step into the trap to get the desired effect. While not attractive, this has proven very, very effective for us as we haven’t lost a single koi when relying on the minefield approach. Although not our intent to actually “catch” anything, we have “lost” several and found two as far as 10m from the pond.

    I remove the traps when we note that none have been triggered for a few weeks. Note that heavy rains will trigger the traps.

  17. The deep method and the decoy of a statue have been my saving grace. The herons still come by and visit from time to time, but I haven’t lost a fish, knock on wood, in over a year now. I have a 15,000 gallon lower pond that my 8,000 gallon upper pond spills into. We so enjoy the view and the “music” of the waterfall. When the heron would not fly away when we came into the yard, firecrackers helped to scare them away.

  18. I have to agree with Rick, my fish seem to have been safe from day 1 due to deep water. In each of my ponds the water exceeds 4′ in various areas. I live in a very “country” area and predators tend to get a drink and leave the fish alone. Fortunately I also have 2 dogs and a cat that make sure their territory is well marked. A combination of deterrents will always work best. My decks also protect most sides of all the ponds but 1. The top pond is exposed but deep and still no losses.

  19. I have 2 cranes that visit every July for ‘High Tea’. I now have a fence (using 3/8″ metal rods, 22″ high, installed 2′ apart, about 3-4′ away from the stones at the edge of my pond. I attach nylon string (or old grass trimmer cord) to these stakes, and then fasten iridescent plastic 22″ strips ( using ‘hunters’ tape) to this cord about every foot. This is a very inexpensive treatment and it REALLY works!!

  20. I have had a problem with a large white egret and he ate most of my fish, by the time I saw him with one of my fish hanging out of his big mouth I looked for all types of netting and put it up he still got my fish then I finally got Large Pizza pans that would float put a few of those in my pond and he has not been back they only cost a few dollars and I still have a few of my fish and no more egret. hope this helps someone or some fish GOOD LUCK

  21. I also have floating items in my pond, I place planters in styrofoam containers so they are pleasant to look at while floating. I also use ceramic tiles and place styrofoam under it and place plants on them. They roam around the pond and are pretty. Some of them have anchors to keep them near the edges to scare predators. We also have planters with noisy plants and or wind chimes near the edges. Dried bamboo works nicely near the edges, it’s noisy and creates much movement. Happy ponding!

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