The state of Texas began stocking largemouth bass in 1941 back when TPWD was known as Texas Game, Fish, and Oyster Commission. From 1941 through 1971 only northern strain largemouth bass were stocked into Texas public waters. In 1972, TPWD began stocking lakes with Florida largemouth bass and since then has stocked 325 public lakes. TPWD stocks Toledo Bend and Sam Rayburn almost every year with Florida largemouth bass. Florida largemouth bass are stocked to either increase the allele frequency (number of Florida largemouth bass genes) of the existing population, to supplement limited recruitment, or help recover from a catastrophic loss of fish. Florida largemouth bass are capable of growing more rapidly and reaching larger sizes than northern largemouth bass. TPWD has been successful in altering the genetic composition of bass populations through its stocking program. TPWD stocks most of its Florida largemouth bass not to increase the overall number of fish in a lake but to increase the Florida allele frequency in order to provide a population of bass capable of growing to larger sizes. In 2006 there was nearly 15 million bass requested by the TPWD management districts, with just 6 million fish actually produced and stocked. Having shortfalls between what is requested and what TPWD hatcheries can realistically produce is typical for most years. It is because of these shortfalls and total cost, that TPWD must become more efficient with its bass stockings and still obtain our objectives.  

Factors that may reduce survival of stocked bass fingerlings include hauling stress, lack of prey once stocked, and predation by other fish or by larger bass. From previous studies it is fairly certain that mortality of stocked fish from hauling stress is minimal. TPWD studies have also found that stocked bass were feeding within 12 hours of being stocked, however it is uncertain if stocked fish were as successful at capturing prey as bass that were not stocked or reared in a hatchery. A study was conducted by TPWD at O.H. Ivie reservoir where it was estimated that as much as 25% of largemouth bass fingerlings that were stocked were eaten by other fish, mainly other bass within 24 hours of stocking. It costs nearly 50 cents to produce a bass fingerling, the state stocks roughly 6-8 million bass a year at a cost of about 3-4 million dollars where 25% of that will not last more than 24 hours because in essence it is serving as fish food.
 
Habitat likely affects survival and predation of stocked largemouth bass more than any other variable. TPWD protocol is to stock largemouth bass into the best inshore habitat available at multiple sites with stocking locations no closer than 2 km apart. Largemouth bass predation success is correlated to habitat complexity, and it is thought that increased complexity reduces predation success by increased visual barriers by plant stems as well as prey to utilizing the available cover to hide. It is commonly known that certain fish species exhibit seasonal preferences for different areas and habitats. Many studies have been conducted to document seasonal habitat use, but unfortunately most have focused on a single species or the interactions of a few similar species. Knowledge of seasonal habitat use by predators may aid managers in determining when and where stocked largemouth bass will have reduced predation risk. TPWD is conducting a study is to determine if predator assemblage, abundance, and size structure varies seasonally within selected habitat types in Toledo Bend Reservoir. Toledo Bend Reservoir was chosen because it is comparable to other large East Texas reservoirs in terms of habitat types present. Toledo Bend is considered a high priority fishery, given angler use and the local economic impact it provides therefore receiving nearly 10% of all Florida largemouth bass stocked into Texas reservoirs annually. Fieldwork began in April and crews will spend about a week each month through November on this project. Upon completion of this project the next study will be to actually stock fish into our study sites and determine their survival rate to ensure that we indeed are stocking bass fingerlings into areas that will provide the highest degree of survival and success.

As always, if you should have any questions concerning this article or have any other fishery questions please don’t hesitate to contact me at This e-mail address is being protected from spambots. You need JavaScript enabled to view it or call me at 409-384-9572. Good Luck and Good Fishing!

Dan Ashe is a fisheries biologist with Texas Parks and Wildlife Department. He has worked out of the Jasper, Texas field office since 2005 helping to manage east Texas reservoirs including Sam Rayburn and Toledo Bend. Dan has also worked as fisheries biologist in Puerto Rico, California, and Alaska but now calls Texas home.