Fisheries biologists often refer to a three-pronged approach to fisheries management: habitat, fish and people. To develop and sustain high quality recreational fisheries, all three components need to be addressed.
Most biologists tend to stress that habitat – from water quality and quantity, to the amount of structure, including aquatic plants and resulting forage – may be the most critical. However, managing fish, which is often seen as stocking more or “better” fish, is often the first thought of anglers. Meanwhile, the people aspect, which includes engaging the public in stewardship of the resource, participation in outdoor recreation and regulations regarding harvest, is often the most visible approach.
This column will focus on fish stocking but show examples of how the Florida Fish and Wildlife Conservation Commission (FWC) integrates all three of these management aspects to make stocking successful. And, it emphasizes that even after nearly three-quarters of a century of active state fisheries management, learning how to use hatchery fish effectively is still a learning process.
Lake Talquin, an 8,800-acre reservoir near Tallahassee, is an excellent example of the FWC’s three-tier approach. The reservoir, which was formed by damming the Ochlockonee River for hydroelectric generation, is best known as a crappie and bream fishery. Historically, the steep embankments provided a limited littoral (shallow area near the shore) zone for bass to spawn and where submerged aquatic plants could grow. Those plants help shelter the eggs from currents and also provide places for baby fish to hide and feed. As a result, natural bass production in the reservoir was not optimal.
Consequently, FWC biologists implemented its three-phased approach to manage largemouth bass in Lake Talquin, beginning in 2000. These activities included planting shoreline vegetation, stocking hatchery fish and implementing an 18-inch minimum size limit on black bass. Today, native bulrush, much of which was transplanted by FWC programs, comprises 5 percent of the shoreline. The long-term goal is to have bulrush on 7 percent to 10 percent of the shore. Once accomplished, natural reproduction of bass and other sunfish should be enhanced.
Meanwhile, since 2000, FWC has stocked more than 700,000 advanced-sized (3- to 4-inch) hatchery bass to improve the population. These fish are extremely difficult to raise to this size in large numbers at hatcheries because of their cannibalistic nature and the amount of pond space and time required. However, these stockings using fish from the two FWC freshwater hatcheries (Blackwater in Santa Rosa County, and the Florida Bass Conservation Center in Sumter County) proved immensely successful.
Timely releases of 2- to 3-inch hatchery bass, reared in ponds on natural food, resulted in 17 percent to 40 percent of the young fish collected in Lake Talquin from October 2000-2003. These young hatchery fish were born the previous spring (called Age-0 fish by biologists). Three years later, hatchery fish comprised about 25 percent of the angler catch from bass tournaments on Lake Talquin. These fish were identified using a metal-detecting wand to determine the presence of a coded-wire tag. These tags are about the size of the tip of a mechanical pencil lead, and biologists implanted them in the cheek of the hatchery fish before stocking (see MyFWC.com/fishing, and click “Stocking Locations/Info” for a video of the tagging process).
Since 2010, at least 15 hatchery bass weighing 8 to 11.5 pounds have been recaptured from Lake Talquin. Since only about one-fifth of the stocked fish were tagged from 2000-03, many more fish could have been harvested, or caught-and-released, by anglers who didn’t know they were holding a hatchery-spawned bass. Supplemental stocking and aquatic plant management activities, as well as the 18-inch minimum length limit may all have contributed to the success of the largemouth bass trophy fishery on Lake Talquin.
This accomplishment is impressive, given that successful largemouth bass stockings into existing populations have been very limited in Florida and the southeast, and were generally discontinued. Previous stocking efforts typically involved phase-I fingerling bass, which were pond-reared in hatcheries on zooplankton to a size of about 1 to 1.5 inches. Those fish quickly became vulnerable to predators when stocked in public water bodies. Given the prolific nature of bass when suitable spawning habitat is available, the supplemental hatchery fish typically did not contribute much to anglers’ overall success.
Unfortunately, raising enough 3- to 4-inch bass in hatchery ponds to supplement a significant number of lakes in Florida is cost prohibitive. As a result, two alternate approaches are being experimented with. The first involves use of new artificial diets and a method FWC developed to train fingerling bass to consume it, rather than each other, so they can be grown in intensive tank management systems more cost effectively. The other involves tricking the adult bass in hatcheries using light and temperature to spawn earlier (or later) than they would in nature. This allows pond-reared, phase-I bass to be stocked earlier in the year when there is better forage, such as baby threadfin shad.
Charlie Mesing, the Habitat and Species Conservation biologist responsible for helping manage Lake Talquin, and other FWC scientists experimented with the latter approach recently. Their 2008 scientific publication concluded that stocking low numbers of 3- to 4-inch pond-reared bass prior to the threadfin shad spawn, which occurs around the middle of May in Lake Talquin, can result in significant fishery improvements.
In March 2012, FWC released approximately 800,000 small bass (1-2 inches) as a one-time early “experimental stocking” to compare to previously larger sized fish stocked in May from 2000-2010. Moreover, all of these fish were carefully tested to make certain that they contain the proper Florida bass genetics, were disease/parasite free and will not adversely affect the fish populations into which they are stocked.
Largemouth bass are not the only fish stocked in Florida’s fresh waters by the FWC. Anglers can learn more about the species and locations stocked by visiting MyFWC.com/Fishing. Recently, signs have been posted at boat ramps where stockings have taken place. The signs have a QR code that allows anglers with smart phones to scan it to learn more about the stockings that took place at their locale.
Blackwater hatchery is responsible for much of the striped bass and sunshine bass production that takes place in Florida. Being at the extreme lower limit of their range, striped bass were already challenged but damming of their spawning rivers nearly completely eliminated natural reproduction. The sunshine bass is a hybrid created in the hatcheries by crossing a female white bass and male striped bass, and they don’t reproduce naturally. So the fact is that if you catch either of these fishes in Florida, they almost certainly came from an FWC hatchery. Recently, several trophy-sized striped bass have been reported from Panhandle rivers, owing to these stocking efforts.
During 2010-11, more than 4 million freshwater fish were placed in public waters. FWC is on schedule to meet or exceed that goal for 2011-12 and continues to study ways to make stocking more successful, while enhancing habitat and using appropriate regulations to ensure Florida remains the Fishing Capital of the World.