Ask An Angler: How Old Is A Five-pound Bass?

Weighing a largemouth bass with a fish scale makes it easy to determine the weight of your catch but figuring out how old that bass is more of a challenge. The growth rate of bass is a complex process influenced by various factors from one section of the country to another. Some experts claim the caloric content of bass forage is the key to bass growth rates, while others think water temperature plays the most important role in the growth of largemouth bass.

Fisheries biologists in my home state of Missouri usually measure the growth rate of largemouth bass by the length of the fish. My home waters of Lake of the Ozarks has a minimum length limit of 15 inches for keeping a largemouth bass and biologists have told me a 15-inch Lake of the Ozarks largemouth is usually around 3 years old.

They Grow Bigger In Warm Weather

Water temperature and forage availability are probably the two leading factors contributing to the growth rate of bass. The warmer the water the more bass will feed and the more forage available the more calories bass can consume, which increases the fish’s growth rate. Studies have revealed the optimum water temperature range for bass fry growth is between 80 to 86 degrees and the optimum range for adult bass growth is 75 to 86 degrees. Water temperatures throughout the Southern states stay warmer longer than the Northern states so Southern bass grows bigger and faster than their Northern cousins.

The Lake Matters

Various factors can also cause different growth rates between two neighboring lakes. A lake with good water quality such as having good dissolved oxygen contents and optimal fertility will bolster a bass’ growth rate whereas a lake with poor water quality due to raw sewage input or agricultural runoff can cause stress on bass and reduce growth rates.

The size of the bass population compared to the amount of available prey could create different growth rates between two fisheries. One lake may have the perfect amount of bass for the available forage, but the other lake may have too many bass for the amount of prey. The lake with the right ratio of bass per prey will have good growth rates, while the other lake that has too many bass will result in a stunted bass population with very poor growth rates. This is a frequent occurrence on mismanaged ponds and smaller lakes.

Boys Vs. Girls

Two other factors influencing the growth rate of a bass are its subspecies and gender. Largemouth bass are classified into two subspecies: Northern strain (distributed throughout most of the country) and Florida strain (residing mainly in Florida, Georgia, Texas, and California). Both subspecies have the same growth rate for the first three years but after that, the Florida strain largemouth will exceed the growth rate of the Northern strain bass. The growth rates of male and female bass widely vary but females generally grow larger and live longer than males.