Empirically Speaking

Why Bass Harvest is So Important for Small Waters

By Dr. Wes Neal

            Bass fishing today is a lot different than it was 60 years ago. Back then, we kept what we caught—everything we caught. It was dinner. So, what changed?

It all started with competitive fishing. During the earliest bass tournaments, there were no livewells, and most legal bass arrived to weigh-in dead. The sight of so many dead bass over a weekend tournament ruffled quite a few feathers, as local anglers worried that the excessive harvest would hurt their fisheries. Even worse, anglers targeted and killed the largest fish.

            Enter Ray Scott and the Bass Anglers Sportsman Society, better known as B.A.S.S. After founding B.A.S.S. and hearing complaints about tournament effects on bass populations, Ray went to a trout tournament in Colorado and observed how they would catch and gently release their target fish. According to an article by Bill Dance, Ray noted, “How excited the anglers were to release those little trout,” and thought, “This would be a great idea for bass fishing.” Many conversations, brainstorming efforts, and invention of the livewell later, live release fishing became the standard for tournament bass fishing, and soon caught on with recreational anglers as well.

            Most anglers would agree that catch-and-release fishing has a net positive effect on bass populations in larger public waters. Reducing harvest increases catch rates, and returning the largest fish to grow and be caught again should lead to better size distributions of fish. There are drawbacks as well, including training fish to be hook shy, but that can be a topic in a later article. The consensus is that catch-and-release fishing makes bass fishing better in large reservoirs, big rivers, and natural lakes. However, this is not the case in small impoundments.

In ponds and small lakes, harvesting bass is not only encouraged, it is usually required to have fast bass growth rates and larger maximum sizes. Most southern states recommend harvesting anywhere from 15 to 35 pounds of bass per acre per year, depending on the specific pond situation. For example, in Mississippi I often recommend that anglers catch and remove 30 pounds of small bass per acre over the course of the year in a pond that is properly fertilized. So why are ponds so different from the big public waters? The difference is in productivity and complexity.

Properly designed and constructed ponds and small lakes are usually much more productive than reservoirs due to several factors. First, reservoirs usually have a much greater watershed to surface area ratio, meaning that they have a lot of water flowing through them, flushing nutrients downstream. Reservoirs may have 100 to 600 acres or more of watershed for every surface acre of lake, whereas most ponds in the eastern U.S. have ratios of 10:1 or less. Arid regions can be higher, but ponds with rations of 100:1 or more are typically only constructed in the desert southwest. Less flow means that the nutrients are retained longer so they have a better chance to be used and recycled.

Second, ponds and small lakes are shallower than most reservoirs, allowing more habitat to be usable for both photosynthesis, which drives productivity, and for fish. When you fish a reservoir for bass, you may fish for them shallow in the spring and fish for them deep on creek channels in the summer. The fish are not everywhere in the lake at all times, and fishing in much of the open water can be fruitless. A pond may hold fish in nearly all habitats that have sufficient oxygen levels, especially because all but the deepest areas are essentially shoreline habitat.

Third, ponds are much simpler systems. We strive to manage for a single apex predator— Largemouth bass. That means bass get to eat all available prey, including stocked fish species that may include bluegill, redear sunfish, fathead minnows, golden shiners, threadfin shad, tilapia, and so on. Conversely, larger systems are more complicated. They can contain many top predators, including gar species, flathead and blue catfish, bowfin, and a whole host of other species. In these systems, bass have to share the wealth.

In addition, we have more control in ponds, and we often manage for increased productivity using crushed limestone, fertilization, and/or feeding. Liming the pond makes nutrients more available, fertilizing adds nutrients, and feeding bypasses the nutrients altogether (and adds more nutrients). These management tools can double or triple the productivity of the pond or small lake.

The result is that the biomass (or weight) of bass a pond can support is substantially greater than that of a larger system. For example, a typical southern reservoir may support 20-40 pounds of bass per acre, while a small southern pond may support 50-100 pounds. Moreover, larger systems are typically public, so fishing pressure can be extremely high. In that case, overharvest is a real concern and catch-and-release helps protect the fishery. Ponds are normally private, and private ponds are rarely fished as heavily as public waters, so overharvest is much less of a concern.

Finally, bass are really good at reproduction in ponds. The habitat is just right, and those nasty predator species that eat baby bass in big systems are not usually in ponds. Thus, bass in ponds, especially southern ponds, tend to overpopulate.

That brings us back why you should plan to keep fish from ponds. It is all about channeling more of the biomass into fewer, bigger bass. I like to think about it in this rather simplistic way:

Suppose a pond can support 100 pounds of bass per acre. This is its carrying capacity based on the current productivity of the pond. If you change feeding, fertilization, or water quality, this can affect the carrying capacity, but otherwise it is relatively stable through time.

Those 100 pounds of bass per acre can be distributed to many size combinations. You might have 100 bass that weigh 1 pound each, or 50 2-pounders, or 20 5-pounders, or just 10 10-pounders. Regardless of the size distribution, the pond can only support 100 pounds per acre.

Thus, in order to grow big bass, you need to have fewer bass. This is why we recommend removing fish. In the theoretical pond above with 100 1-pound bass per acre, if you can reduce the population to 20 fish per acre and keep it there, eventually the population will be composed of 20 5-pound fish. The 20 bass will use the available resources (food) to reach the carrying capacity.   

Of course, natural waters have a combination of sizes and all kinds of crazy interactions that this simplistic view omits, but you get the point, right? Maybe there are 50 fish less than half a pound, 20 fish 1-2 pounds, 12 fish 2-4 pounds, and 8 fish over 4 pounds with one whopper that is 12 pounds. Regardless of the distribution, the trick to shifting the pond to fewer, larger fish is to remove many of the smaller bass. Food that they would have eaten becomes available to the remaining bass, which then can grow larger.

Harvest recommendation for ponds are designed to remove little bass to make big bass. This situation is much different from what led to catch-and-release in public waters. Catch-and-release started to prevent overharvest of bass and excessive removal of big bass. We use harvest of small bass in ponds to prevent overpopulation and to make more big bass. In fact, harvest recommendations usually call for harvest of fish less than 13 or 14 inches. These fish may not be legal size in some bass tournaments.

There are caveats and special circumstances, of course, and every pond is different; but generally, proper harvest leads to more desirable bass populations. In addition, you should adjust harvest through time as your fishery improves. Eventually you may need to harvest larger fish, say up to 16 inches, to keep bass growing on a steep trajectory. If you are good at telling a male bass from a female bass, you can also selectively harvest males, as they do not have the same trophy potential as a female. A trophy male bass is a 5-pounder!

Finally, it is critical to document, document, document! Keep good records of your fishing effort, catch, and harvest. If you record these data every time you fish, you can easily tally up your harvest at the end of the year and see if you are meeting your harvest objectives. Fishing logs also provide a historical record of your management effort and can show if your pond is on a trajectory to become a trophy factory, or just a sardine factory.