Synopsis
The hypothesis that an increase in the mortality rate of Atlantic salmon would be produced by the synergistic effect of osmotic stress and of stress due to the presence of predators was tested by putting two groups of smolts (one acclimated to seawater and the other not acclimated) into a tank containing predators. These smolts were tested afterwards in a seawater-challenge test, together with smolts of the control groups for both experimental groups. The mortality rate of the non-acclimated and predator-exposed smolts was 90%, and that of the seawater acclimated and predator-exposed smolts 43%, compared to no mortality among the control groups. Lack of acclimation to seawater did not in itself induce any lethal stress, but in conjunction with predator-stress there was a synergistic effect, leading to an increase in the mortality rate. The hypothesis is therefore considered to be valid.
Article PDF
Avoid common mistakes on your manuscript.
References cited
Barton, B.A. & C.B. Schreck. 1978. Metabolic cost of acute physiological stress in juvenile steelheads. Trans. Amer. Fish. Soc. 116: 257–263.
Barton, B.A., C.B. Schreck & L.A. Sigismondi. 1986. Multiple acute disturbances evoke cumulative physiological stress responses in juvenile chinook salmon. Trans. Amer. Fish. Soc. 115: 245–251.
Bennett, A.F. 1978. Activity metabolism of the lower vertebrates. Ann. Rev. Physiol. 400: 447–469.
Black, E.C. 1958. Hyperactivity as a lethal factor in fish. J. Fish. Res. Board Can. 15: 573–586.
Evans, D.H. 1980. Osmotic and ionic regulation by fresh and marine fishes. pp. 93–122. In: M.A. Ali (ed.) Environmental Physiology of Fishes, Plenum Press, New York.
Heisler, N. 1980. Regulation of the acid-base status in fishes. pp. 93–122. In: M.A. Ali (ed.) Environmental Physiology of Fishes, Plenum Press, New York.
Hvidsten, N.A. & P.I. Møkkelgjerd. 1987. Predation on salmon smolts, Salmo salar, in the estuary of the river Surna, Norway. J. Fish Biol. 30: 273–280.
Hvidsten, N.A. & R.A. Lund. 1988. Predation on hatcheryreared and wild smolts of Atlantic salmon, Salmo salar, in the estuary of River Orkla, Norway. J. Fish Biol. (in press).
Jakobsson, S. & T. Järvi. 1977. Anti-predator behaviour of 2-year old hatchery reared Atlantic salmon salmo salar and a description of the predatory behaviour of burbot Lota Iota. Zool. Revy 38: 57–70. (In Swedish).
Lahlou, B. 1980. Les hormones dans l'osmoregulation des poissons. pp. 93–122. In: M.A. Ali (ed.)>Environmental Physiology of Fishes, Plenum Press, New York.
Mazeaud, M.M., F. Mazeaud & E.D. Donaldson. 1977. Primary and secondary effects of stress in fish: some new data with a general review. Trans. Amer. Fish. Soc. 106: 201–212.
Milinski, M. & C. Löwenstein. 1980. On predator selection against abnormalities of movement: a test of a hypothesis. Z. Tierpsychol. 53: 325–340.
Nichols, D.J. & M. Weisbart. 1985. Cortisol dynamics during seawater adaptation of Atlantic salmon Salmo salar. Amer J. Physiol. 248: R651–R959.
Radakov, D.V. 1958. On the adaptive significance of shoaling of young coalfish (Pollachius virens). Vopr. Ikhtiol. 11: 69–74. (In Russian).
Radakov, D.V. 1973. Schooling in the ecology of fish. John Wiley & Sons, Chichester. 173 pp.
Rehnberg, B.G. & C.B. Schreck. 1987. Chemosensory detection of predators by coho salmo (Oncorhynchus kisutch): behavioral reaction and the physiological stress response. Can. J Zool. 65: 481–485.
Schreck, C.B. 1981. Stress and compensation in teleostean fishes: response to social and physical factors. pp. 295–322. In: A.D. Pickering (eds.) Stress and Fish, Academic press, London.
Specker, J.L. 1982. Interrenal function and smoltification. Aquaculture 28: 59–66.
Wood, C.M., D.J. Turner & M.S. Graham. 1983. Why do fish die after severe exercise? J. Fish Biol. 22: 189–201.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Järvi, T. Synergistic effect on mortality in Atlantic salmon, Salmo salar, smolt caused by osmotic stress and presence of predators. Environ Biol Fish 26, 149–152 (1989). https://doi.org/10.1007/BF00001031
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00001031