During the 1950s Dr. H.S.Swingle of Auburn University, after years of research, determined that stocking largemouth bass and bluegill was the best set of species to provide long-term fishing in ponds and small impoundments. This combination of bluegill and largemouth bass stocked at a 10:1 ratio provided stability and a “balanced” population.
Balance refers to a situation where both the bluegill and largemouth bass are reproducing and providing catches of harvestable fish of both species. Keep in mind that to this early generation of pond owners a harvestable bluegill was 4 ounces and a harvestable largemouth bass was less than a pound. This combination of stocking largemouth bass and bluegill at a 10:1 ratio was adopted by most game and fish agencies in the southeast during the early 1950s.
Today’s landowners have different objectives. They want quality largemouth bass fishing that includes catching high numbers of bass in the 2- to 4-pound range, with a reasonable possibility of catching a largemouth bass 8 pounds or larger. To obtain this type of fishery requires more than fertilizing and feeding.
Dr. Rich Noble, retired fisheries professor at North Carolina State University says that largemouth bass management is a fight against Mother Nature. Noble stated, “In nature, largemouth bass populations tend to be dominated by small fish. For viability of the population it is an advantage to have large numbers of small reproducing bass rather than moderate numbers of large fish. Lake fertility doesn’t change the size distribution much. If we are going to have big bass, we have to get the food to them, and the small bass are a big problem preventing that.”
To understand why these small bass are such a problem we need to look at the total pounds of fish a pond can produce and the changing relationships among largemouth bass, bluegill and other prey species. At a given fertility level, a pond supports predictable poundage of fish. This total poundage or carrying capacity is typically comprised of 25 percent bass. Biologists speak of a pond’s carrying capacity of largemouth bass in terms of pounds per acre. The total pounds of largemouth bass per acre is pretty consistent over time, even if the size composition of the bass population changes. Therefore, you can have a high number of small bass or a smaller number of larger bass.
Bass have optimum sizes of food fish (prey) that are needed for fast, efficient growth. Eating food smaller than the optimum size is inefficient because more energy is burned in catching small prey than is gained by eating it. Bass growth is dependent on prey growing to the right sizes to become optimum for each of the various sizes of bass in the population. High populations of small bass deplete the bluegill reproduction, leaving few bluegill to grow to the proper size for larger bass growth.
How do we correct an overpopulation of small bass? The most economical and efficient management approach is to decrease the population of small bass by angling. The bass size structure can be shifted upward by aggressively removing the small bass. The total poundage of bass in the lake will not increase, but the remaining fish will grow larger.
What size largemouth bass should you remove? Typically, the bottleneck occurs at bass lengths of 10 to 16 inches. Largemouth bass within this size range are so abundant that they deplete prey needed for growth by larger bass. I usually recommend the pond owner start out removing all bass under 16 inches until an established harvest quota is met. Sometimes it is very difficult for anglers to remove bass that are 8 to 10 inches because it goes against their “catch and release” mentality. Also, if you catch a bass that is 18 inches or larger that is very skinny, take it out. It is also important to remove these bass in as short a time as possible. If the harvest is stretched out too long the bass will replace themselves.
Although bass can be removed anytime of year to improve size structure, an excellent time to remove high numbers of bass is spring. Catch rates are usually highest in the spring and bass can be sexed this time of year. Since the females are the ones that grow larger and reach trophy size, it is to the pond owner’s advantage to remove as many males as possible. Males are highly vulnerable as they move into shallow water to prepare spawning nests and guard the young. Also, harvesting bass early will allow the forage (bluegill) to increase their spawning success, thus more food for the remaining bass.
As a general rule, most fishery professionals recommend the removal of approximately 30 pounds of bass per acre from a well-fertilized pond. This can be accomplished on a good weekend on a 2-acre pond. However, as the lake increases in size it becomes a challenge to harvest the quota of bass. I know of two lakes 75 to 100 acres in size that had 2,000-3,000 pounds of bass removed in one year by angling, so it can be done. It may require you to have a few tournaments with friends to get enough fishing pressure to accomplish your harvest goals.
Selective harvest the largemouth bass population, just like fertilizing or feeding, should be continued year after year. The bass population, by nature, will continue to produce large numbers of small bass, which will be contrary to your goal of larger quality bass.
As the population responds to selective harvest the size needing reduction will change, typically requiring larger fish to be removed. If you started by removing fish less than 16 inches, after a few years you may want to move this up to 18 inches and under. Hook and line sampling can give a good indication of the size distribution of bass in the population, especially the overabundant size range.
Quality largemouth bass management is best achieved by the use of multiple management techniques– such as fertilization, feeding, stocking additional prey species, aeration, etc. However, harvesting bass by angling to thin the population is one of the most effective and least expensive management practices that can be initiated to produce quality bass fishing.
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.
One of the most frequently asked questions to private-fisheries consultants is, "How can I make my largemouth bass grow faster and larger?" To produce heavier fish you not only have to increase the length, but also the girth
Bass management in ponds is complex. Considerations include stocking rates for new ponds, feed and fertilization rates, liming, harvest rates, and the prey fish species to use in the pond.All of these factors will influence the bass population, but the prey fish species in the pond is a critical factor that deserves very careful consideration.Almost all good bass fishing ponds have bluegill as a primary forage base, but other species can be added to increase the food available for bass.
One of the basic principles of pond management is that fish grow rapidly if they have plenty of food, but very slowly or not at all if food is scarce. For most ponds in the South, within 18 months after the initial stocking the pond is usually supporting the maximum weight of fish for which food is available.
The most common problem faced by lake owners today is one in which the bass population is stunted due to lack of adequate forage. The larger the lake the more difficult this problem is to correct.
The first step to correct this problem is to aggressively remove bass by hook and line. It is usually recommended to remove the smaller bass, those that are 15 inches and under. This will allow the bluegill population to expand and eventually furnish more food for the bass.
Threadfin shad have proved to be excellent supplemental forage when stocked in private fertile waters. Threadfin rarely exceed 5 inches in length, making them an ideal-size food item for almost all predators.
Threadfin are pelagic (open water) schooling fish. A flurry of shad breaking the surface means that there are larger fish feeding on them from below. This tight schooling activity means that shad can provide a great deal of food for the bass even though each individual shad may only be 3 to 4 inches long. In a study in California, one 15- pound striped bass was examined that had almost 700 threadfin shad in its gut. In a reservoir or a pond, largemouth bass do not feed on individual shad but rather engulf dozens at a time when they come up beneath a school. If the bass are feeding on bluegill, they usually have to chase them down one at a time.
The threadfin shad is closely related to the gizzard shad, but does not grow as large and is more temperature sensitive. They are a temperate species, and some mortalities occur when the water temperature drops below 43 degrees F. Deeper lakes tend to provide areas that act as thermal sanctuaries. The threadfin can usually be distinguished from the gizzard shad by its smaller body size and its yellow fins, especially the yellow in the caudal or tailfin. Smallmouth and striper fishermen sometimes refer to them as “yellowtails.”
Threadfin shad are sexually mature at approximately 2 to 2 ½ inches. Spawning begins in the spring when the water temperature reaches 65 to 70 degrees F. Threadfin are heavy spawners with a single female capable of laying 10-12,000 eggs. Spawning has been documented form March to mid-September. Females, trailed by several males, lay eggs along the shoreline, usually around daylight and the adhesive eggs stick to aquatic vegetation. Hatching occurs in about three to five days. The fry have clear bodies and are almost invisible to the naked eye until they are about an inch long.
Shad are filter feeders and feed on both phytoplankton (microscopic one-cell plants) and zooplankton (microscopic animals). They are so efficient at filtering that some catfish farmers have begun stocking shad in their production ponds to improve water quality.
However, sometimes this filtering ability can have a negative impact on the bream population since young bluegill also feed on zooplankton. If the pond owner wants to produce large bluegill where shad have been introduced, then the use of automatic fish feeders is advised. Large, well-fed bluegill will produce more offspring, which will also enhance the growth of the largemouth bass.
Threadfin are extremely delicate and must be handled with care. They are usually harvested from the hatchery pond, loaded onto an oxygenated tank truck and transported directly to the customer’s pond. Once the truck is at the pond the fish are discharged through a pipe to avoid handling. Although the existing bass population will eat some of the shad, many will escape to spawn and become established in the owner’s lake
Another benefit of having threadfin in your lake is the exciting fishing it creates. Once shad are established, they will often school near the surface late in the afternoon. When the waters are calm, schools of shad ranging in size from 5 to 10 feet in length can be seen creating a very gentle rippling effect on the surface of the water.This almost always triggers a feeding response from the largemouth bass.As the bass attacks underneath the school, it appears as if a small depth charge has gone off and someone has thrown a handful of silver dollars into the air.This activity has caused the author many a backlash as I tried to capitalize on this feeding frenzy.
In summary, if your objective in managing your lake is to produce bigger and heavier largemouth bass, then there are several management strategies you will need to implement. One thing that you should consider is putting them on a diet of threadfin shad.