The largemouth bass (LMB), Micropterus salmoides is a Centrarchid freshwater species native to North America and the most sought-after sport fish in the U.S. Demand for live and fresh LMB in the food has increased in the U.S. with an estimated production of 3.8 million pounds of live weight with an estimated value of $29 million (2023 US Census of Aquaculture). However, LMB are often raised in the southern U.S. where high summer temperatures prevent harvest and transport that increases demand, and price, during summer months.
This exploratory pilot study presents results of the first commercial production of largemouth bass for the live food fish market using a floating in-pond raceway system in a private reclaimed rock quarry pond. The objective of this study was to characterize water temperature, water quality, feasibility, and to describe pitfalls and best practices of raising LMB in floating in-pond raceways in a semi-natural waterway in a temperate climate. The fish farm, located in Piqua, OH, started in 2023 by placing two floating in-pond raceways (IPRS) with an estimated volume of 213 m3 each in reclaimed rock quarry pond (17 acres, max depth of 23 ft). Approximately 10,000 feed-trained LMB fingerlings with an individual average weight of 76.17±19.77 g (CV=26%) were stocked on May 5-8, 2024, in one of the raceways. Fish were fed a commercial diet (48% protein and 18% lipid) using automatic feeders, with a daily feed ration set at 3% of total body weight that was re-adjusted to the initial body weight bi-weekly during the first 4 months. Mortality was checked daily. Water temperature and dissolved oxygen were measured once per day, in addition the deployment of a HOBOâ MX pH and Temperature logger (MX2501) set up to record data every hour. Pond water was sampled weekly and analyzed for total ammonia nitrogen (TAN), nitrite nitrogen (NO2--N), and nitrate nitrogen (NO3—N) once per week during the first four months, and then every two weeks.
The LMB in this study had steady growth across 487 days with an average weight at time of sale of 628 ± 99 g. Water quality remained ideal across the study. The water temperature at the time of harvest, September 2nd, was 22.87 oC. At harvest, the fish were quarantine in saltwater tanks before going to market with zero mortality. Unfortunately, prior to harvest, a mortality event related to human error occurred on April 19, 2025 (day 352) which accounted for an estimate of 4,780 fish, with an individual average weight of 396 g, for a total of 1,893 kg, that affected yield and FCR of the pilot study. Best practices included predatory bird deterrents, as well as shades and co-culturing tilapia to mitigate filamentous algae growth. Accidental mortality notwithstanding, this pilot demonstrated that a floating in-pond raceway is effective for growth of market-sized LMB when in employed in a reclaimed rock quarry pond.