Stocking-hatchery reared largemouth bass for healthy fisheries

The Florida Fish and Wildlife Conservation Commission (FWC) may be close to a breakthrough with stocking bass for better fishing opportunities. We hear it all the time, “Bass management is easy, just stock more fish.” Truth is – it isn’t that simple. FWC biologists, as well as other fishery research experts, have understood for years that merely stocking fingerling bass rarely improves fishing.

Biologists at the FWC’s Florida Bass Conservation Center (FBCC) in Sumter County began pioneering research that enabled scientists to produce larger advanced fingerling bass (approximately 4 inches long).

The FBCC concentrated on specific conditions where stocking fingerlings actually works. For example, stocking fingerling bass into a new reservoir or community pond built for fishing, or stocking them into a lake following a drought, after a fish kill, or after completion of a habitat-restoration program can restore a population more quickly than natural reproduction alone.

The biologists understand that bass stocking results in a more effective management tool with a larger hatchery, so they can eat a greater variety of prey. Being bigger also is an advantage because fewer predators can eat them.

Sounds simple, but the problems have been significant. First, largemouth bass are typically spawned naturally in hatchery ponds, because they don’t respond well to hormones, such as those used to spawn striped bass. In addition, small bass are cannibals, and they don’t like artificial foods, which are used in hatcheries for catfish and trout. Therefore, bass were historically grown in fertilized outdoor ponds with lots of zooplankton (tiny floating animals such as insect larvae). Predators, including minnows, insects and frogs, ate the eggs and baby fish. As the survivors grew larger, other predators such as birds began feasting on the young bass where they concentrated in outdoor ponds.

Consequently, the FBCC was designed to intensively culture largemouth bass indoors using state-of-the-art technology. The FBCC has the potential to produce more than 1 million advanced fingerling largemouths annually.

Through research, scientists found a way to trick bass fry into eating artificial food. It was discovered that by crowding fry together and feeding them live brine shrimp (the size of a gnat) they’d go into a feeding frenzy and be less choosy in what they ate. That allowed researchers to mix in artificial food that was about the size and color of the brine shrimp. Once the bass fry began eating the artificial food, it was easier to progressively train them to take bigger pellets as the bass grew in size.

Other research has improved culture conditions, fish health management, handling and hauling protocols. Now scientists are comparing survival rates between hatchery fish that are simply stocked at a boat ramp in the traditional manner, versus those distributed into vegetated habitats around the lake, so they are more dispersed and avoid predators more easily.

One study found that advanced fingerling largemouth reared in ponds on live aquatic organisms and stocked into Lake Talquin, near Tallahassee, fed on fishes more successfully and grew faster than their wild counterparts during their first year of life in the reservoir. At the end of the first year, hatchery fish comprised 40 percent of the bass that survived from that year’s spawn during a year when 25 fish were stocked per acre. Five years after supplemental bass stocking, hatchery fish accounted for 20-27 percent of bass caught in tournaments. Research is being conducted in Lake Talquin to determine whether pellet-reared hatchery bass will survive as well as hatchery fish reared on live feed.

The Lake Talquin study has provided optimism that stocking advanced sizes of largemouth bass at the appropriate time will become a more widespread and successful management tool. Information gained from research and adaptive management is critical to long-term success of bass stock-enhancement programs. Specific spawning strategies are being used to protect the genetic integrity of Florida bass populations in the state.

To be completely successful, the FWC is dedicated to maintaining healthy habitats to stock the fish, as well as making sure anglers follow the necessary rules to ensure safe, sustainable, quality recreational fishing for everyone.

Instant licenses are available at MyFWC.com/License or by calling 888-FISH-FLORIDA (347-4356). Report violators by calling *FWC or #FWC on your cell phone, or 888-404-3922. Visit MyFWC.com/Fishing/ for more Fish Busters’ columns.