The Department of Fisheries at Auburn University is conducting a research program to improve fishing in small ponds and lakes in the southeastern United States. This research is in cooperation and support from the private sector including American Sport Fish and primarily focuses on improving the size of bass caught by anglers. A problem facing pond owners who want quality fishing is overabundant bass populations. Bass tend to over reproduce in smaller water bodies and removal of fish by angling is typically not sufficient to reduce the number of fish. This causes fish growth to be reduced and results in overcrowded and small stunted bass that typically are not very large. The goal of the program is to explore and demonstrate alternative methods to produce larger bass for pond owners.
In our first project, we increased the typically stocking in a new pond from 1,000 bluegill per acre to 1,500 bluegill per acre and stocked 100 bass per acre. In the past, 100 bass per acre was the recommended stocking rate. Even though these bass were only about 2 inches long when stocked in June, 40 to 60% of these fish survived the first year. We also estimated that these bass ate about 130 to 170 lbs per acre of bluegill, which is a tremendous amount of bluegill. Even in a good well managed pond, bluegills can obtained a biomass of about 300 lbs per acre, but many of these bluegills are greater than 6 inches and can’t be consumed by bass. Even with harvest of small bass less than 14 inches (15-20 lb per acre removed), these ponds became bass crowded and out striped the bluegills that served as food. In fact, after 3 years, it was hard to find a bluegill less than 5 inches in these ponds. From this research, we determined that the old 10 bluegill to 1 bass stocking ratio should be increased to about 35 bluegill to 1 bass. Thus, a new pond owner who wants larger bass should stocked for example, 2,500 bluegill and 75 young bass per acre
Four years after establishing our pond populations of bass and bluegill, we stocked threadfin shad as an alternative prey fish for the bass. About 1 year later, the threadfin shad population exploded, our bass got fat, and growth rates and size of big bass increased. After 6 years, we had a number of bass that weighed 8 to 9 lbs. We also noticed our bass keep feeding during the cold winter months and bass fishing was good even though the water was cold.
Because young bass consume so many small bluegills, we also recommend to pond owners to remove as many bass less than 10 inches as possible. This means down sizing tackle, but if you wait till the bass get to 12-14 inches and these bass are real abundant, the damage to your prey fish forage base has already be done.
In attempt to completely eliminate bass reproduction, we have also examined stocking all female bass into new ponds. I currently recommend stocking about 20 female bass that are about 10-12 inches long into new ponds that have a protected water shed where male bass can’t get into the system. Prior to stocking all female bass, these ponds were stocked heavily with bluegill and golden shiners. After 3 years, we had bass up to 5 to 6 lbs and these fish were really fat. Right now, the only way to produce all females is to inspect each fish in spring to determine if eggs are present in these 1 year old fish. If one male fish gets into the pond, reproduction will likely occur.
Finally, I did some work in one pond with stocking adult tilapia. The idea is to stock adult tilapia (around 1 lb) in spring, these fish reproduce, and as the water cools in fall, the young tilapia become easy prey for bass. As expected in the fall, bass over 15 inches really improved their body condition and got fat. We noticed in the fall, young tilapia grew quickly, and most were 5 inches or longer. Tilapia are a wide bodied prey fish like bluegill and bass can only eat these fish up to 1/3 their length. Thus, the largest Tilapia a 15-inch bass can eat is 5 inches long. So if your pond is really stunted with most bass 15 inches or less, threadfin shad or golden shiners will be a better forage. For populations that have lots of big bass, tilapia would be good alternative. However, in most areas where water temperatures get as low as 45 to 47o F, all tilapia will die and these would need to be restocked the following spring.
Mike Maceina is a professor in the Department of Fisheries and has been at Auburn University for nearly 19 years. Most of his research focuses on understanding and management of sport fish including bass, crappie, white bass, striped bass and catfish.