While working on an article about crappie fishing for Georgia Sportsman Magazine, I interviewed several Georgia Department of Natural Resources Fisheries Biologists. I found out how they measure crappie population in Georgia reservoirs. And I got some specific info on the outlook for several lakes here.
Each year gill nets are put out to survey open water species of fish like crappie, hybrids, stripers and others. To be consistent, the same size and number of nets are put out in the same places each year at the same time. And they are left out for the same length of time each year. A record of all the fish caught it kept to determine that year's population and then compared to other years to get trends.
Here, DNR biologists put out 12 gill nets on each lake in the late fall, varying from early November in the north Georgia lakes to early December in the south. Those nets are checked each day and all fish caught in them collected.
Since I fish the lakes I was asking about, the crappie population and trend was very interesting to me. Crappie populations are very cyclical and great fishing on a lake one year does not mean it will continue being good. These cycles tend to run in a five to seven year pattern.
I was pleased when I was told several Georgia lakes have stable populations of crappie. I was surprised at one of our lakes. Lake Oconee is possibly the best lake in the state. Many fishermen consider an 8 inch crappie the minimum size to keep, and 95 % of the crappie there are that big or bigger. Even better if you like big fish was the news that 30 % of the crappie are between 12 and 14 inches long and 11 % are bigger than that! You have a good chance of catching a lot of keeper size crappie and some trophy fish are also likely to come over the side of your boat.
Fish like bluegill, bass and cats that do not stay in open water are surveyed by shocking them. That is also an interesting process and following the shocking boat around can really be an eye-opener! It is amazing how many fish can come out of hole you just fished and did not get a bite!
The information gathered in surveys like these are used to determine creel limits and size limits in many lakes. For example, in Georgia Lake Oconee has too many small bass and that is not desirable. So size limits are set to allow anglers to keep bass from six to 11 inches long and also those over 14 inches long. The idea is to allow a stockpile of 12 to 14 inch long bass. That size grows fast. Keeping smaller bass allows more food in the lake for the more desirable larger bass.
If there are not enough smaller crappie in a lake biologists may set a size limit on them. Anglers are not allowed to keep crappie smaller than nine inches long so there are more smaller fish to grow to good size before being kept. Populations can be adjusted using this data to some extent.
State biologists have a lot of info that can help you determine which lakes are most likely to produce for you, and also which lakes to avoid. Check with your state agency for more detailed information that can help you.