Take Overall Look to Determine Bass Health
Growing giant bass in private lakes is possible with forage, habitat and a management plan. (Photo: Southeastern Pond)
Southeastern Pond Management
There are not many late-night infomercials selling products to help the user gain weight. Unless someone has started a largemouth bass channel, that is. As fisheries biologists, fat bass get us excited. Why? Because they are one of the best indicators of a healthy fish population.
But measuring largemouth bass “fatness” takes more than passing the eye test. Because they are eating machines, largemouth bass digest their prey quickly. Let’s say you catch a 5-pound largemouth that has recently feasted on a large bluegill. That fish will look fat because it has a bulging stomach. However, if you were to catch that same fish a day later, she would not look nearly as plump.
Interestingly, the primary determinant of weight in fish is its length. A 20-inch largemouth bass in relatively good condition should weigh about 4.5 pounds. However, in ponds with healthy threadfin shad and bluegill populations, it is not uncommon to see a 20-inch bass pushing 5.5 pounds.
On the other hand, a 20-inch bass in a pond with a sub-par forage population rarely tips the scales at more than 4 pounds.
Because there is so much variation in a bass’s length and weight, we use a standard measurement to determine the condition or “fatness” of each fish. A largemouth bass’s relative weight can be calculated by dividing the actual weight of the bass into the length specific standard weight for largemouth bass.
Relative weight is calculated as a percentage where fish below 90 percent are considered less than optimal. Fish with relative weights that fall in the 90 percent to 100 percent range are in good condition. “Fat” bass are defined as those fish over 100 percent.
While balanced lakes that have abundant forage populations will contain bass with average relative weights ranging from 90 to 100 percent, most bass-crowded ponds typically have average relative weights of 85 percent or below. Extremely bass-crowded conditions can produce average relative weights as low as 75 percent.
To explain relative weight a little better, let’s examine a 20-inch largemouth bass that weighs 4.5 pounds. That fish, which any pond owner would be proud of, would have a relative weight of 98 percent. In simple terms, it could be classified as a healthy, fast-growing bass.
If our electrofishing sample revealed a high abundance of 20-inch bass with average relative weights of 90 percent or above and the other bass in the population were in equally good condition, then we would consider that lake in balance. A 20-inch bass that
weighed 4 pounds would have a relative weight of 87 percent. If the average relative weight of the bass in that population were similar to this fish, we would determine that the pond is not reaching its top potential and that management is needed.
Let’s say that 20-inch bass pushes 5.5 pounds, which would boost its relative weight to 121 percent, and that other fish in the population, are just as fat. We would have a two-word recommendation for the pond owner: “Go fishing!”
Southeastern Pond Management is the official fish-care provider for the Bass Pro Shops PAA Tournament Series, ensuring that PAA anglers’ final-day catches are released healthy and into the same lake from where they came. Southeastern Pond Management also provides PAA tournament staff with advice and recommendations for fish care.
With offices in Alabama, Mississippi and Tennessee, Southeastern Pond Management helps landowners take care of their “liquid assets” with year-round management advice and guidance. Get hooked up with Southeastern Pond Management by visiting www.sepond.com, email them at pondhelp@sepond.com or follow on Facebook.
