Hatchery-reared fish are frequently adjusted (tempered) to the higher water temperatures present in the water bodies where they are to be stocked. This study was undertaken to determine the necessity of such tempering practices. This study used rainbow trout ( Oncorhynchus mykiss ) and brown trout ( Salmo trutta ) reared at 11.2 °C. The first two trials for each species were designed to simultaneously determine the upper incipient lethal temperature and 100% lethal temperature over a 14-day period. The third trial for each species evaluated the effects of an exaggerated 12-hour tempering regime on fish survival after placement in elevated water temperatures. After transfer from a water temperature of 11.2°C, no rainbow trout survived at 26°C, and only 50% survived at 25°C. No brown trout survived at 22°C and only 50% at 20°C. Survival of rainbow trout was not improved by the 12-hour tempering regime where water temperatures were slowly increased from 11.2°C to either 25°C or 26°C. Similarly, tempering did not improve brown trout survival at either 20°C or 22°C. These results suggest that tempering is not needed when hatchery-reared trout are reared and stocked at the water temperatures within the range of those used in this study.
Piper, R.G., McElwain, I.B., Orme, L.E., McCraren, J.P., Fowler, L.G. and Leonard, J.R. (1982) Fish Hatchery Management. U.S. Fish and Wildlife Service, Washington DC.
Hartman, K.J. and Preston, B. (2001) Stocking. In: Wedemeyer, G.A., Ed., Fish Hatchery Management, 2nd Edition, American Fisheries Society, Bethesda, 661-686.
Smith, M.A. and Hubert, W.A. (2003) Simulated Thermal Tempering versus Sudden Temperature Change and Short-Term Survival of Fingerling Rainbow Trout. North American Journal of Aquaculture, 65, 67-69. https://doi.org/10.1577/1548-8454(2003)065 2.0.CO;2
Brett, J.R. (1941) Tempering versus Acclimation in the Planting of Speckled Trout. Transactions of the American Fisheries Society, 70, 397-403. https://doi.org/10.1577/1548-8659(1940)70[397:TVAITP]2.0.CO;2
Wedemeyer, G.A. (1996) Physiology of Intensive Culture Systems. Chapman and Hall, New York. https://doi.org/10.1007/978-1-4615-6011-1
Mather, M.E. and Wahl, D.H. (1989) Comparative Mortality of Three Escoids Due to Stocking Stressors. Canadian Journal of Fisheries and Aquatic Sciences, 46, 214-217. https://doi.org/10.1139/f89-029
Clapp, D.F., Bhagwat, Y. and Wahl, D.H. (1997) The Effect of Thermal Stress on Walleye Fry and Fingerling Mortality. North American Journal of Fisheries Management, 17, 429-437. https://doi.org/10.1577/1548-8675(1997)017 2.3.CO;2
Noga, E.J. (2000) Fish Disease: Diagnosis and Treatment. Iowa State University Press, Ames.
Harmon, T.S. (2009) Methods for Reducing Stressors and Maintaining Water Quality Associated with Live Fish Transport in Tanks: A Review of the Basics. Reviews in Aquaculture, 1, 58-66. https://doi.org/10.1111/j.1753-5131.2008.01003.x
Wynne, F. and Wurts, W.A. (2011) Transportation of Warmwater Fish: Equipment and Guidelines. Southern Regional Aquaculture Center, Stoneville.
SDGFP (South Dakota Department of Game, Fish and Parks) (2019) 2019 Annual Technical Fish Stocking Report. Pierre. https://apps.sd.gov/GF56FisheriesReports
SDGFP (South Dakota Department of Game, Fish and Parks) (2015) Strategic Plan 2016-2020. Pierre. https://gfp.sd.gov/userdocs/docs/strategic-plan-2.pdf
Jobling, M. (1981) Temperature Tolerance and the Final Preferendum-Rapid Methods for the Assessment of Optimum Growth Temperatures. Journal of Fish Biology, 19, 439-455. https://doi.org/10.1111/j.1095-8649.1981.tb05847.x
Kilgour, D.M. and McCauley, R.W. (1986) Reconciling the Two Methods of Measuring Upper Lethal Temperatures in Fishes. Environmental Biology of Fishes, 17, 281-290. https://doi.org/10.1007/BF00001494
Kientz, J.L., Barnes, M.E. and Durben, D.J. (2017) Concentration of Stocked Rainbow Trout Catch and Harvest by a Small Number of Recreational Anglers. Journal of Fisheries Sciences.com, 11, 67-76. https://doi.org/10.21767/1307-234X.1000111
Cherry, D.S., Dickson, K.L., Cairns Jr., J. and Stauffer, J.R. (1977) Preferred, Avoided and Lethal Temperatures of Fish During Rising Temperature Conditions. Journal of the Fisheries Research Board of Canada, 34, 239-246. https://doi.org/10.1139/f77-035
Hokanson, K.E.F. (1977) Temperature Requirements of Some Percids and Adaptations to the Seasonal Temperature Cycle. Journal of the Fisheries Research Board of Canada, 34, 1524-1550. https://doi.org/10.1139/f77-217
Bishai, H.M. (1960) Upper Lethal Temperature for Larval Salmonids. ICES Journal of Marine Sciences, 25, 129-133. https://doi.org/10.1093/icesjms/25.2.129
Wagner, E.J., Bosakowski, T. and Interlmann, S. (1997) Combined Effects of Temperature and High pH on Mortality and the Stress Response of Rainbow Trout after Stocking. Transactions of the American Fisheries Society, 126, 985-998. https://doi.org/10.1577/1548-8659(1997)126 2.3.CO;2
Walker, H.D., Coates, G.I. and Wilhelm, S. (2000) Impacts of Increased Tempering Lengths on Twenty-Four-Hour Survival of Hybrid Striped Bass Fry. North American Journal of Aquaculture, 62, 316-318. https://doi.org/10.1577/1548-8454(2000)062 2.0.CO;2
Trushenski, J.T., Larsen, D.A., Middleton, M.A., Jakaitis, M., Johnson, E.L., Kozfkay, C.C. and Kline, P.A. (2019) Search for the Smoking Gun: Identifying and Addressing the Causes of Postrelease Morbidity and Mortality of Hatchery-Reared Snake River Sockeye Salmon Smolts. Transactions of the American Fisheries Society, 148, 875-895. https://doi.org/10.1002/tafs.10193
Barton, B.A. (2002) Stress in Fishes: A Diversity of Responses with Particular Reference to Changes in Circulating Corticosteroids. Society for Integrative and Comparative Biology, 42, 517-525. https://doi.org/10.1093/icb/42.3.517
Hnath, J.G. (1983) Hatchery Disinfection and Disposal of Infected Stocks. In: Meyer, F.P., Warren, J.W. and Carey, T.G., Eds., A Guide to Integrated Fish Health Management in the Great Lakes Basin, Wildlife Disease Association, Lawrence, 121-134.
Edwards, W.J., Babcock-Johnson, L. and Culver, D.A. (2002) Field Testing of Protocols to Prevent the Spread of Zebra Mussels (Dreissena polymorpha) during Fish Hatchery and Aquaculture Activities. North American Journal of Aquaculture, 64, 220-223. https://doi.org/10.1577/1548-8454(2002)064 2.0.CO;2
Pucherelli, S.F., Portz, D.E., Bloom, K., Carmon, J., Brenimer, S. and Hosler, D. (2014) Quagga Mussel Contamination of Fish Haul Trucks by Fish and Development of Effective Potassium Chloride and Formalin Treatments. Journal of Applied Aquaculture, 26, 132-148. https://doi.org/10.1080/10454438.2013.873756
Wehrly, K.E., Wang, L. and Mitro, M. (2007) Field-Based Estimates of Thermal Tolerance Limits for Trout: Incorporating Exposure Time and Temperature Fluctuation. Transactions of the American Fisheries Society, 136, 365-374. https://doi.org/10.1577/T06-163.1
Selong, J.H., McMahon, T.E., Zale, A.V. and Barrows, F.T. (2001) Effect of Temperature on Growth and Survival of Bull Trout, with Application of an Improved Method for Determining Thermal Tolerances in Fishes. Transactions of the American Fisheries Society, 130, 1026-1037. https://doi.org/10.1577/1548-8659(2001)130 2.0.CO;2
Bidgood, B.F. and Berst, A.H. (1969) Lethal Temperatures for Great Lakes Rainbow Trout. Journal of the Fisheries Research Board of Canada, 26, 456-459. https://doi.org/10.1139/f69-044
Alabaster, J.S. and Welcomme, R.L. (1962) Effect of Dissolved Oxygen on Survival of Trout and Roach in Lethal Temperatures. Nature, 194, 107. https://doi.org/10.1038/194107a0