Tennessee Lake Management and Tennessee Pond Management: the Truth About Tilapia and Trophy-Largemouth Ponds

Many private lake and pond consultants have been telling pond owners across the Southeast, for years now, that tilapia are essential to stock if the goal for the pond is trophy bass. These consultants claim that tilapia produce more forage for the bass than any other fish that can be stocked, and therefore improve bass growth. If this were true, there would be a whole lot of private ponds and lakes in Tennessee, Alabama, and Georgia that had ten-, twelve-, and fourteen-pound largemouth. Our competitors would have whole sections of their websites devoted entirely to big bass photos from their clientele, and they would have to have a dedicated employee tasked solely with updating the big bass photos. Because more than a couple of our competitors push tilapia on their clients as though these fish were the sole key to growing giant bass. How do I know this? Because we have worked on dozens of ponds and lakes where the landowner had previously used one of said competitors, and had stocked tilapia for a few or several years running. And yet somehow their bass didn’t reach those enormous sizes promised by those other consultants. Perhaps all of those ponds just happened to have some mysterious environmental factor that made growing big largemouth impossible? Over and over again, we have come behind our competitors who had stocked tilapia into a private pond or lake for years with no appreciable results, and within a year or two had the impoundment coughing up six-, seven-, eight-, and nine-pound, and larger, largemouth. Here’s some basic biology for you, from the Southern Regional Aquaculture Center: Nile tilapia, the species most commonly stocked in ponds, reaches sexual maturity at an average age in ponds of five to six months, at a size of 150 to 200 grams. The average female produces two to four eggs per gram of body weight. So that’s 800 eggs for a female at the upper end of the average size range at which tilapia begin spawning. If you happen to have some larger female tilapia (the females on average get half as big as the males) in your pond that weigh as much as twenty-four ounces or more, those larger females could be cranking out a whopping 2,720 eggs per spawn. Texas A & M Agrilife Extension puts a lower cap on the fish’s fecundity, claiming that some females can produce as many as 1,200 eggs per spawn. Texas A & M also states that female tilapia, under ideal conditions, may spawn every seventeen days. If the person you buy the tilapia from has even a hint of a conscience, he won’t bring you the fish until sometime in May; they’ll all be dead by mid-October, so that’s about eight spawns you might get under completely ideal conditions. Now let’s consider another freshwater fish. A 1949 study by Charles Estes found that this fish began spawning in March in reservoirs in east Texas, and spawning continued all the way into October; some percentage of the population was spawning every month from March through October. That same study found an average egg count for one female specimen of this species of just under 12,000 eggs; the study also references another study done in Wisconsin (Schloemer 1942) that found one female of this species can produce up to 60,000 eggs. What’s this mystery fish I write of? The humble bluegill.It doesn’t take a mathematician to see which species is a more prolific breeder. So then why are there so many pond consultants pushing tilapia as though they were the secret to growing giant bass? Perhaps it’s as simple as economics - the economics of keeping that pond consultant’s company afloat. Tilapia are a tropical species; they have to be re-stocked every year. No matter how many you stock in April or May - and years when winter lingers like it did this year, stocking them in April would be a quick way to a tax write-off - any that aren’t eaten by bass by early October will become food for your neighborhood buzzards. Yearly re-stocking means a yearly check for that consultant, even if it never leads to any improvement in your pond. The consultants that push these fish on you will claim that they make for a smorgasbord for your bass when they die - but largemouth aren’t scavengers, for one, and beyond that, in the average pond for which the bass need help, 90% of the largemouth will be too small to eat any tilapia larger than four or five inches. Tilapia can grow from a few inches to three pounds or more in the span of six months; how long do you think that puts them in the size range that your bass can eat them? Bluegill that you stock in your pond this spring, unless they make a meal for a big bass, will still be in your pond in mid-December; they’ll still be in the pond next spring when spawning time rolls around, and you can bet they’ll be making babies for your bass to eat. And bluegill don’t grow from a few inches to three pounds in six months’ time.