Brenda Groth wrote:yes there is a chance that it might get too cold here for tilapia..right now the bubbler keeps open water MOST of the time but we dropped well below 0 this week and even some creeks froze over.
our neighbors have bullheads and had a huge bullhead loss 2 years ago, not really sure why..but that was a concern to us.
neighbors the other way have pike, bluebills, perch, large mouth bass and put in some baby fish last year..not sure what all..they tried to get out all the pike first..not sure how successful they were on that.
also i have a gob of baby goldfish..i'm sure they are being eaten by some critters..but in the spring it is amazing how many babies i see..and some are as big as 4" or so..by now..
this pond has cattails, iris, lotus, lily, arum and lots of water plants as well as the native water plants (i put in babies from a bunch from a water garden supply store 2 years ago)..oh it also has sterile lythrum in it which hasn't spread ..at least so far.
It's good to see the interest in fish species and an effort to balance the population.
I'll add a few points from an aquarist's point of view. Personally, I think all tilapia should be eliminated from North America. They are that invasive. The big problem is they excavate the substrate and kill the plants. They are an ecological disaster waiting to happen. They should even be in home aquariums, they are that invasive if released by some uneducated aquarist in a warm zone.
I'd also skip the goldfish if there is any chance of them escaping your pond. Goldfish are carp, they grow huge and destroy spawning sites for other fish much like tilapia do. Tilapia are different in another way. They are mouth brooders. That means they carry their young in their mouths. So destroying the spawning sites of other fish doesn't impact Tilapia. They multiply and overpopulate any aquatic environment put in and crowd out other species as do carp. So unless you plan to farm them, I'd pass on Tilapia.
There is a myth I'd like to dispel about catfish. They do NOT eat the waste of other fish. Catfish are extremely picky eaters. They are indeed mostly bottom feeder but they are also carnivores that put Bass and Pike to shame. A catfish can easily eat another fish of the same or even bigger than it is itself. In a small pond, you would soon have nothing but catfish. Big ones can even eat birds. They will eat until they look like they should explode. But no, they simply swim around with the other fish hanging out of their mouths as the swallowed parts digest.
On the upside for catfish, they are generally the best-tasting fish going. They don't taste fishy at all and the bones aren't an issue for any catfish species. If the pond is small the fish will stay small except for goldfish. They keep growing until they die if they can get enough food. They can never get all they want, they never stop and they trash their environments as well by scouring the bottom for the merest morsel. They also eat plants. Tilapia uproot plants. So neither is suitable if you want a decoratively planted pond. As mentioned though, Tilapia won't survive a cold snap and definitely not a winter. They are tropical fish native to the Nile River. You don't want them loose in your southern states.
None of the North American fish tolerate chemical pollutants such as runoff for long. In some cases it makes them change sex. Once that happens, they can't breed. Fish like carp and suckers can tolerate pollutants because, unlike catfish, they eat a lot of vegetable material and vegetation uptakes whatever is available. Sometimes the plants die, and sometimes they become tolerant. A fish that eats them and then is itself eaten by something higher up the food chain sends the toxins up the food chain to the apex predators such as bass, pike, perch, pickerel and so on.
The more people who maintain and enjoy water gardens the better. So I applaud your efforts. I'd do it myself but the trees around my house won't allow it and the coons would clean them out pretty quickly anyway.
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