I will never forget a presentation I saw back when Lake Oconee was new and the slot limit was being explained. A picture was shown with five bass lying on a table. They ranged from six inches long up to 15 inches long and weighed from a few ounces to over two pounds. All those bass were taken from Lake Oconee and were all the same age.
There are a lot of things that influence bass growth, especially in their first year or two. Bass spawn at different times during the spring. If a bass fry hatch early, which means in March or early April most areas in Georgia, it will grow faster than those hatched in late April or May. Early hatchers are big enough to eat the fry of shad and bluegill when they spawn so they get lots of high protein food. Late hatchers are too small to eat them and actually have to compete with other fry for the same food.
Genetics may play a role. Just like some families seem to produce a lot of six foot tall people, some female bass may produce offspring that grow faster than others. But since females produce offspring with different males each year, and often in the same year, that genetic factor is diluted.
Fertility of the lake or pond a bass lives in greatly influences its growth rate. A well fertilized farm pond will produce fast growing bass while a very infertile lake will produce slow growing bass. And water temperatures make a difference. That is one reason South Georgia lakes like Seminole and Eufaula produce so many quality bass. They have a longer growing season with warmer water.
How do you determine how old a bass is? Just like trees produce annual rings in their wood, bass produce annual rings in their scales that will give you a good indication of their age. You can look at a scale under a magnifying glass and count the rings. A more accurate way to measure bass age is to examine the "ear bones" or otoliths and count rings in it, but you need special training to extract the bone, cut it and examine it.
So how old is that bass you just caught? In some detailed studies, on average, reservoir largemouth bass in our area are about seven inches long when one year old, 11 inches long at their second birthday and 14 inches long at three years old. In another year a four year old largemouth will be about 16 inches long and a five year old bass will be just over 17 inches long.
Spotted bass grow slightly slower, with a one year old measuring just under six inches, two years olds are ten inches long and three year olds are 13 inches long. A four year old spot will be 15 inches long and a five year old a little less than 17 inches long.
We all know how much a bass can vary in weight related to its length, so some three year old largemouth that are keepers will just barely weigh a pound while others will be well over a pound and a half. And spots seem to vary even more than largemouth.
Very few bass live five years or longer and most of us can verify that by the number of bass 17 inches long or longer we land. A ten pound bass might be ten years old or even older, and one that size is rare.
When you catch a bass consider the above lengths to get an idea how old it is. Then decide if you really want to eat one that has survived so many years. Keep the youngsters and let the older ones go to continue growing.