Once constructed, our ponds become part of the local food chain and as a consequence our koi are on the menu
Expectations of eternal harmony are unrealistic - both within and around the pond |
We are naturally upset when wild animals invade but it's important to understand that they are just trying to survive. It's not surprising to see so many wild animals dwelling within the cities, their habitat is being consumed by urban sprawl and the city affords bountiful hunting grounds
With realistic expectations and design considerations however, fish loses can be nil or acceptably low in most circumstances Fish, being low in the food chain, are potential prey for many animals. Among them are cats, raccoons, weasels and birds such as herons and hawks
For the most part, cats and raccoons are moot - not a threat in a pond with a depth over 3 feet. Their hunting grounds are the small water gardens, often only 18 inches in depth. Herons are bold intelligent birds that will stake out your pond and visit it regularly until the food supply is gone. Evolution has specifically engineered them for catching fish and they are a real threat. The worst predators are weasels. Tiny but deadly, they can swim under water - ice covered or not. They will modify their hunting patterns and are insatiable
Ultimately its important to realize that once a predator has targeted your pond, you have a real problem that needs to be dealt with |
There are several pond design strategies to help deter successful predation
Deep Pond
First, your pond should be deep - at least 5 feet but preferably there should be a section 7 feet in depth. This provides a relatively safe sanctuary for your fish. Also, the ponds side walls should be relatively step and there should be no shallow sections less than 2 feet. With these features alone, raccoons and cats are unlikely to be successful. This will also deter herons too because they like set down on land and then walk into the water. They will not step into a step drop off and consequently have to fish from the shore
Large Perimeter Stone
With the addition of larger rock, 1 foot or more above the surface, Herons will have to spear at least 1 foot below there feet to just reach the surface of the water. This is not like how they like to fish. But as mentioned, they are crafty. One client told me how the bird landed beside his pond and then would fly over it, spearing into the water as it passed
Members of the weasel family are the worst adversaries . I have 3 clients who have had their ponds quietly and completely fished out. If you are familiar with Toronto, one client is at Highways 404 & 7 - not exactly in the country
Electric Fence
Aside from design modifications, you may also have to utilize some other strategies - your success rate will vary. These include motion detector water jets, having a dog, covering the pond with netting or wiring, artificial owls or herons etc. As far as I'm concerned, an electric fence is your best option. While the other strategies are deterrents, an electric fence creates a physiological barrier for the predator. After 1-2 jolts, the predator will want no part of your property, let alone your pond. We do carry and install electric fences and have had very good success with them
Some predators like Ospreys and other fish eating raptors are not a problem in the city, at least I have not heard of this in Toronto. If you are in the country with a large pond you will ultimately have to accept loses as snapping turtles and other hungry predators join the fray
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