There probably is no other topic in the freshwater fishing industry that conjures up more excitement and fascination than catching giant bass. Let’s face it; truly giant bass are rare creatures. Most people have never seen a bass over 10 pounds in real life. I electrofish ponds on almost a daily basis, and I don’t see that many fish over 10. And when I do, I get as excited as the client I have on the boat with me. Heck, maybe even more excited.
Catching a trophy bass takes on an almost mythical aura for some folks; akin to harvesting a record-class whitetail or bull elk. For many, it is truly the fish of a lifetime. But, like everything else in this world, there are exceptions to the rule. For a select few pond owners, catching a trophy bass is a relatively common occurrence. How can that be? What are they doing that others are not?
Before going any further, it is appropriate to define what a trophy bass is. George Perry’s infamous world record would certainly be considered a trophy bass. After all, at 22lbs 4oz it is the bass by which all others are measured. In recent years, a number of huge bass caught in Texas and California have come close, but no one has yet certified a bass that has broken Perry’s record set in 1932.
The definition of a trophy depends to some extent upon the individual and the situation. What about the 3lb “whale” your son or daughter caught with a Snoopy rod while fishing for bream? That’s certainly a trophy for a young angler. What about location; do we define a trophy differently depending upon where you live? After all, each state designates a “record” bass and these vary considerably by geographic region. What about the designation fisheries scientists use to categorize a bass of trophy length (i.e., 25 inches long)? A 25 inch bass with a relative weight of 110 (see Wildlife Trends Volume 7, Issue 3) weighs right at 10 pounds. This is probably as good a definition as any, but it is still half the size of George Perry’s world record! For the sake of this discussion, I will use 10 pounds as my definition of a trophy bass. By the way, I have personally angled a number of bass in the 8 and 9 pound class, but I still have yet to catch a legitimate 10. For those of you who have, you know you have reached an angling milestone.
The goal of most pond owners is a well-balanced fishery that offers a high catch rate of quality-sized bass and bream, with the potential to grow and catch an occasional trophy. In fact, most of the ponds we manage fall under the umbrella of “balanced” fisheries. Managed properly, balanced ponds will support bass populations typified by a relatively high abundance of 2 to 4 lb fish, but also yield an occasionally trophy bass. That said, achieving the goal of balance is a significant task in and of itself. It requires, among other things, manipulating pond fertility, selective harvest and periodic monitoring.
However, there is a contingency of pond owners whose primary objective is the production of trophy largemouth bass. These guys want to grow really giant bass and lots of them. They don’t want to settle for an occasional giant, they want giant bass to be the norm. This is where pond management diverges a bit from the more traditional methods used to manage a balanced fishery. Trophy bass management is more intensive, both in terms of factors to consider and cost per acre. But for many, the rewards are well worth the added effort and expense. Like everything else in life; the more you put into it, the more you get out of it.
Ponds managed for trophy bass will not provide angler catch rates as high as those typical of a pond managed for balance. Because each and every pond can support a finite biomass of bass – a level that is largely determined by the fertility of the water – trophy bass ponds, by necessity, will support a lower density of bass. However, the average bass will be much larger that those found in a balanced fishery. There is definitely an inverse relationship between the density of bass in a pond and the average size of the bass.
There are a number of factors that must be considered to successfully manage a pond for trophy bass production:
- Age, Growth and Mortality
- Nutrition
- Genetics
- Latitude
- Pond Size
- Water Chemistry/Fertility
- Harvest
- Sex Ratios
- Habitat
- Luck?
The remainder of this series will examine each of these factors in more detail. Hopefully, this information will help you determine if trophy bass management is right for you. I’ll begin with a discussion of how the interaction of age, growth and mortality factors into the trophy bass formula. Discussion of the other factors I have listed will be addressed in future issues of Wildlife Trends.
Age, Growth and Mortality
Fish population dynamics are governed by three dynamic rate functions: growth, recruitment and mortality. The interaction among these three factors determines how a population of fish is structured. With regard to trophy bass management, I want to concentrate on growth and mortality over the typical lifespan of a bass. I will do this by referencing Figure 1 below.
There are certainly exceptions, but in general, the maximum age of a bass in southern ponds is about 12 years old. Additionally, the natural mortality rate for a given bass population in the southeast is about 25% per year. As a side note, most pond owners don’t realize that about one-fourth of the bass in their pond die from natural causes each year.
The result of a 25% natural mortality rate is identified by the blue line and the left y-axis (Figure 1). To simplify the discussion, I arbitrarily started with 100 bass at time zero. Therefore, you can think of this in absolute numbers, number per acre, or the percentage of a particular cohort (age-group). As you can see, by year 6 about 20% of a given cohort of bass are left in the population; by year age-9, about 10%; by age-12 very few. Stated another way, of all the bass produced in a given year, roughly 3% will still be living 12 years later. This certainly makes intuitive sense. After all, it should be obvious that bigger, older bass are much rarer in a pond than smaller, younger bass. So as bass in your pond grow and become older, a portion of them die each year; leaving fewer fish that will even have a chance to make it to trophy size.
Now look at the red curve and the right hand y-axis. This is a growth curve computed from a large sample of bass collected from Lake Eufaula, a well-known trophy bass fishery on the border of Alabama and Georgia. As you can see, it takes the average bass in Lake Eufaula nearly its entire life to reach the length at which it might weigh 10 pounds. By the time a bass has reached this size, she has very few sisters her age left in the population. By the way, really big bass are nearly always females…more on that in a future issue.
Now look at the green curve, this is from a 40-acre pond in Alabama, at almost the same latitude. However, this pond is aggressively managed for trophy bass. It was stocked with bass fingerlings in 2001 so that’s the reason for the short curve terminating at age-6. Notice how the bass have grown in 6 years to a length it takes 12 years in Eufaula. Notice too, how many more fish remain in a particular cohort simply because the fish aren’t as old and have not been subjected to the forces of natural mortality for so long. The result is not only more trophy bass per acre, but also more trophy bass that still have years left to grow even bigger. So the bottom line is; the faster you can get bass growing early in life, the better your chances of producing a trophy fishery.
From this example, it should be obvious that growth rate is the primary factor to consider in the production of trophy bass. The faster a bass grows, the better chance it has of reaching trophy size before the grim reaper comes calling. Also, the better chance it will attain truly gigantic proportions like 12lbs, 15lbs or even larger! A 12 year old bass that weighs 10lbs is not likely to get much bigger, whereas a 10 pounder that is only six years old just might make it to 15lbs plus under optimal growing conditions.
It all sounds pretty simple so far. Increase the growth rate of bass and get ready to start adding pages to the record book. So what is the best way to maximize bass growth and ultimately start producing legitimate trophies? Again, there are a number of factors to consider. Of those factors previously mentioned, nutrition is undoubtedly the most important. That, along with genetics will be the topic of discussion in the next issue. However, all of these variables factor into the trophy bass equation in some way and we will address these in subsequent issues of Wildlife Trends.
As we progress through this series, please keep in mind that there is no cookie-cutter formula for maximizing the production of trophy bass. Although the primary factors that dictate bass growth rate come into play in every pond to one degree or another, every pond is uniquely different in some way. A factor that limits the growth of bass in one pond may not be limiting in another pond. Therefore, it is always advisable to seek the advice of a professional fisheries biologist. They can help you stay on course with your trophy bass management program, and help you allocate your resources most efficiently.
