A Greener View

Question: We have a pond consisting of about 110 gallons of water; in which we have about 22 Koi. Our problem these last few months is the neighborhood has become overpopulated with stray cats. What can we do to prevent them from invading our pond?

Answer: Cats tend not to be a problem with most backyard fish ponds, but when one does figure out how to catch them, it can keep coming back and other cats may pick up the fish catching techniques being used.

Ponds that have problems with mammals catching the fish are often small, hard shell plastic ponds. These ponds are shallow and small, so the fish can't go very far to get away and hide. These small ponds are sometimes referred to as raccoon feeders or heron feeders. Your pond has a lot of fish for its size. There are only so many hiding places in a pond and I am afraid yours doesn't have enough for all the fish to escape.

Create more hiding spaces by creating caves from pipes, pots or rocks set on the bottom of the pond. Depending on the size of the fish and the filtration system, your pond should probably have less than ten fish in it, since the Koi are going to grow. A larger and deeper pond will help too. The new one should have a drop off of several inches from the dry ground to the water level and a few more inches down to the first shelf. Cats don't swim after the fish and so they will have a harder time if the fish can hide and the cat must lean way over into the water to catch the fish.

You can use the motion activated sprinkler device called a ScareCrow®, it senses animals like a security device for the pond. It opens a valve and releases a three second burst of water at the intruder. The ScareCrow® is made by Contech, call them at 800-767-8658 or check out the Scarecrow on the web at http://www.contech-inc.com/products/scarecrow/ .

As a final suggestion, you could create a barrier around the pond. Predator controls based on scent, sounds or taste won't work, and cats can climb fences, but an electric fence wire could work. They are available from farm stores and work very well on all kinds of problem animals. It could be set up to go around the pond or the whole yard.

By the way, you may want to check out the article on Birds versus Cats in the Landscaping and Gardening section of this web site for more information on keeping cats out of your landscape.