Rx for Stunted Largemouth Bass

Every year my partner, Barry Smith, and I get hundreds of phone calls from pond owners whose primary management objective is to produce quality largemouth bass fishing. Usually this conversation includes the following statement: “I am catching a lot of largemouth bass that are a pound in size, but they do not seem to be growing.”

Largemouth bass/bluegill stocking:

More than 50 years ago, research by the Fisheries Department at Auburn University, Auburn, Ala., identified the combination of largemouth bass and bluegill as the set of species that would best provide long-term quality fishing in private ponds and lakes. This basic stocking combination holds true today.

Selective largemouth bass harvest:

However, during the 1970s bass tournaments and TV fishing shows began to preach Catch-and-Release and Don’t Kill Your Catch. This is fine for public reservoirs that have heavy fishing pressure, where protecting populations of adult bass may be important. But, it goes against basic management philosophy of private ponds and lakes. Selective bass harvest is an important and necessary management tool for small impoundments.

I remember when I was a teenager, my brother and I would go bass fishing in a neighbor’s pond, and our idea of catch-and-release was to drag a bass fillet in corn meal and release it in a skillet of hot grease. We didn’t realize it at the time, but we were actually helping that pond from becoming overcrowded with small bass.

Most fertilized bass/bluegill ponds in the southeast will have a carrying capacity of 400 to 600 pounds of fish per acre. These ponds will usually average 400 pounds of bluegill and 100 pounds of bass per acre. A 1-pound largemouth bass will require 5 to 6 pounds of live bluegill to gain a pound of weight. When ponds are stocked initially with bluegill and bass fingerlings, the young bass have an unlimited food supply. At the end of one year the bass begin to reproduce, adding thousands of little ones to the pond. Soon the bass are eating more bluegill than the pond can produce, and the bass growth stops.

Deer biologists and cattle ranchers will tell you that when a heard reaches carrying capacity, for continued growth you have to increase the food supply to the animals by ‘THINNING THE HERD’ or adding supplemental feed. Better yet, a combination of both works the best. The same is true for good bass management.

In a pond or lake that accumulates too many small bass, the adult bluegill population begins to decline over a period of four to six years because the small bass eat all of the bluegill reproduction before they have an opportunity to grow to 6 inches. Have you ever noticed in new ponds that the big bluegill seem plentiful for the first several years, then around year five or six, it is more difficult to catch those big stringers of slabs? The average life span of a bluegill is only five to six years. If you can’t replace the ones that you catch or that die of natural mortality, the numbers quickly dwindle. With few bluegill to spawn and more bass produced every spring, the condition of the fish population continues to go downhill.

My first recommendation to a pond owner who has a stunted bass population is to remove as many small bass, 14 inches or less, as soon as possible. This is not difficult in a two-acre pond, but can be a challenge in a lake that is 20 acres or larger. It can be done, but it requires a lot of effort.

Stocking intermediate bluegill:

The next step is to replenish the bluegill that have been overgrazed by the many small bass. This is best accomplished by stocking significant numbers of 3- to 5-inch bluegill, a size that is called “intermediate” by fishery biologists. This size bluegill is at or near sexual maturity and is usually large enough that the average-size bass has difficulty eating it.

For best results, intermediate bluegill should be stocked at approximately 500 per surface acre. In small ponds or where budgets are not restricted, stocking rates as high as 1,000 per acre have produced excellent results in a few months.

Bluegill that are a tenth of a pound (1.6 ounces) are sexually mature and can begin spawning when the water temperature approaches 78 degrees F. In the South, this means that bluegill can spawn every 30 days from May through September.

Fertilizing with Biologic’s Perfect Pond Plus:

Also keep in mind that a fertilized pond can produce three to four times the bluegill that can be produced in an unfertilized pond. This translates to three to four times the food available for your bass. Keep your pond with a good green color (plankton bloom) with a visibility of 18 to 24 inches. Use 5 pounds of Biologic’s Perfect Pond Plus per acre beginning in March and fertilizing through September. If the pond does not develop a green color, have the water tested to see if it needs an application of agricultural limestone. Just like your food plots or garden, fertilizer reacts better in ponds that have adequate levels of lime.

Automatic fish feeders:

Use an automatic fish feeder to feed the bluegill multiple times daily. This will increase their growth rate, their condition, and reproduction potential. An automatic fish feeder is one of the best investments a pond owner can make. Not only does it help grow big bluegill, but it also provides an area that concentrates fish for your kids to catch. And, it is just fun to watch the fish feed and observe how fast they grow.

The benefit of this supplemental stocking of intermediate bluegill is often seen in the fall or early winter, as the offspring of this stocking begin to gain size and weight, contributing to the food supply of the remaining bass. In crowded or stunted bass populations, continued bass harvest is necessary each year. Usually, removing a total of 30 to 40 pounds of small bass per acre during the year is sufficient to prevent them from becoming overcrowded again.

There are other supplemental forage species that can be added to the pond, such as threadfin shad, golden shiners or tilapia (where legal). These forage species should often be stocked with the intermediate bluegill, but not instead of the bluegill.

Remember your goal is to produce a bass that has a figure like Rosie O’Donnell’s. She didn’t get that figure without the groceries.

Don Keller is a Certified Fisheries Scientist.