Written by Paul Dorsett, Fisheries Biologist
When asked to choose my favorite species of fish, Threadfin Shad is always the first thing that comes to mind. Threadfin Shad play an incredible role in many fisheries as a prolific prey species and their high fecundity (ability to produce lots of offspring) makes them an especially attractive option for stocking. Not only do they occupy a unique ecological niche, they can also provide an exciting angling experience by altering the behavior of predators.
Threadfin Shad are primarily pelagic, meaning they inhabit the open water, rather than the areas near the bottom or the shoreline. They travel throughout their environment in large schools—almost like a single organism—with rhythmic movements reminiscent of flocking birds. When pursued by predators, they will “pop” along the surface and easily lose bright silver, golden or blue-green scales into the water column, which causes further confusion to their pursuers, which include Hybrid Striped Bass, Largemouth Bass and Crappie.
Hybrid Striped Bass are also pelagic fish, aligning their natural hunting style with the school-like nature of Threadfin Shad. Likewise, Largemouth Bass, which generally lie and wait for their prey near structure, will actually alter their feeding behavior to mirror that of Hybrid Striped Bass by following schools of Threadfin Shad in open water. These “schooling bass” are a favorite target for many anglers. Crappie, on the other hand, spend most of their time in deep water habitat and actually orient their bodies vertically in the water column. When a school of shad gets too close to an almost motionless Crappie, they dart out to attack.
In spawning season, Threadfin Shad behavior is worthy of a nature show. They move in mass to deposit eggs and milt onto shoreline grasses. This typically occurs at first light in the spring when the water temperatures reach 72 degrees Fahrenheit. Large populations can cover acres of water surface, making it shimmer in waves as the school changes direction. The eggs adhere to the grass until they hatch within a few days. This frenzied spawning leads to a tremendous reproductive rate.
Fisheries Biologists typically stock a few hundred per acre in the spring which, given the right conditions, can quickly become hundreds of thousands or even millions. These conditions include spring water temperature, photoperiod (daily sunlight), the health of the plankton bloom, and the amount of shoreline grass coverage extending into the water.
If you are interested in stocking Threadfin Shad, it’s important to purchase them from a reputable dealer. Threadfin Shad are delicate and require careful handling and hauling at lower densities than other species. Inexperienced or unscrupulous fish providers may cause more harm by either stocking threadfins that will not survive or stocking the wrong species entirely. Young Gizzard Shad can be easily confused with threadfins. While Gizzard Shad play a role in some fisheries, they can also be detrimental if stocked into the wrong environment. Gizzard Shad will outgrow the mouth width of most predators and the large, unattainable adults can become overpopulated competing for oxygen and space within your waterbody. They can also contribute to turbidity issues in some lakes that are predisposed to this problem.
Another consideration when stocking Threadfin Shad is region. Threadfin Shad are cold intolerant and, generally, cannot handle water temperatures below 40 degrees Fahrenheit. This makes them a more appropriate fit for southern lakes and ponds. Even when they do not succumb to cold temperatures, they move much slower in winter months making them easier prey for predatory fish and fish-eating birds. While your bass may gain tremendous weight from gorging themselves on shad, it is disconcerting to watch a flock of cormorants consume baitfish you worked to provide for your bass. For these reasons, Threadfin Shad should be stocked in the spring to ensure their continued survival.
Finally, since Threadfin Shad solely feed on plankton throughout their lifespan, managing your fishery’s plankton bloom through fertilization may prove vital to their long-term success. If a bloom is not present, your lake will not experience the population explosion for which Threadfin Shad are known. Few waterbodies naturally exist with ideal blooms, so it is common to supplement through fertilization; however, poorly timed or executed fertilization can be destructive. By working with a qualified fisheries biologist, you can ensure your fertilization efforts are productive without experiencing nuisance levels of algae and vegetation.
Contact the experts at 888-480-LAKE (5253) for all of your lake, pond and fisheries management needs.
Paul Dorsett is a fisheries biologist for SOLitude Lake Management in Texas. Paul has nearly 30 years of experience in aquatic ecosystems development and restoration, including fish production, aquatic plant management and water quality. He is licensed by the Texas Department of Agriculture as a commercial aquatic herbicide applicator and a member of the Texas Chapter of the American Fisheries Society. Paul also serves on the board of directors and is past president for the Texas Aquaculture Association as well as the Texas Aquatic Plant Management Society.
Paul holds Bachelor of Science and Master of Science degrees in Wildlife and Fisheries Sciences from Texas A&M University (TAMU). His involvement with aquaculture and business management began in 1989. In 1994, while working as the manager for TAMU Aquaculture Research and Teaching Facility, Paul took on a weekend job working for Bob Lusk of Pond Boss magazine managing private ponds. Private pond management in Texas proved to be his passion and in 1998, Paul and his wife Dawn purchased the southern portion of Bob's business, renaming the business Total Lake Management. They ran the business for 18 years before merging with SOLitude in 2016.
When not watching his kids play whatever sport is in season, Paul enjoys hunting and ranch work. He particularly enjoys time spent improving habitat for wildlife on his property through controlled burns.