One Answer to Fish Over-Population

Too many koi!

Too Much of a Good Thing...

An interesting thing happens when you add fish to a pond with new water at just the right temperature... it's similar to what can happen to people 9 months after a snowstorm.

This photo above is of my pond about a year after it was installed. The pond was installed in May of 2009 and by June we couldn't believe our eyes.  At night, in the underwater lights were hundreds of little fry.  We thought there was NO WAY we could have this many fish, couldn't be!!! The adult fish were all together for years before we put them in the new pond, with very little reproduction.  Guess the new digs made them very happy.

So then what do we do with all these baby koi?

After all was said and done, we had over 300!  Well, they mostly went to other homes eventually -- and yes, we drained the pond to get them out.  Some would stay with us and even make the move with us to our current home and pond.

Here's the important question... how do we keep this from happening again?  We couldn't support this many koi, year after year.  Luckily for us, we had the perfect solution.

Let me introduce Gill--

Gill was a tiny bluegill that actually came in accidentally with another shipment we had received.  He was only about 2.5" long when we took him home.  But he held his own with the koi in the pond and grew eventually to about 11" long.  He displayed normal bluegill behavior.  We saw him hunt, capture and devour more than one unsuspecting dragonfly just hanging out on a plant in the pond.  He also tried for a few years to make a nest and guard it from the koi -- he did eventually give that up.  In the long run, Gill just became chill and hung out with the koi.  He would eat koi food with them, all the while snatching it off the surface of the water as if it were an unsuspecting flying insect of some sort.

Why was Gill so important to our overpopulation?

While Koi and Goldfish are scavengers and will devour fish eggs if they find them, bluegills are much better at it -- and they snatch up, without fail, any fry that end up hatching.  He was so successful that we never had another baby koi in that pond, ever and we lived there 11 more years!

Unfortunately Gill didn't make the move with us, he passed a few months before.  But he lived to be almost 11 years old!

Adding a bluegill to your pond is our number one recommendation for keeping your fish population under control, especially if you have goldfish.  Goldfish are even more prolific when it comes to breeding.  Here's the catch, just add ONE bluegill.  You don't want to take the chance of bluegill breeding also!

What if your pond is already over-populated?  A bluegill can't correct a problem that's already there.  We suggest calling a pet store to see if they take pond fish or offering them on facebook marketplace (for free -- there are lots of people with too many fish).  But as prevention for future fry, you need a Gill!