, Volume 582, Issue 1, pp 35–42 | Cite as

Effects of salmon lice infection and salmon lice protection on fjord migrating Atlantic salmon and brown trout post-smolts

  • Rolf Sivertsgård
  • Eva B. Thorstad
  • Finn Økland
  • Bengt Finstad
  • Pål Arne Bjørn
  • Niels Jepsen
  • Trude Nordal
  • R. Scott McKinley
Fish Telemetry


Effects of artificial salmon lice infection and pharmaceutical salmon lice prophylaxis on survival and rate of progression of Atlantic salmon (n = 72) and brown trout post-smolts (n = 72) during their fjord migration, were studied by telemetry. The infected groups were artificially exposed to infective salmon lice larvae in the laboratory immediately before release in the inner part of the fjord to simulate a naturally high infection pressure. Groups of infected Atlantic salmon (n = 20) and brown trout (n = 12) were also retained in the hatchery to control the infection intensity and lice development during the study period. Neither salmon lice infection nor pharmaceutical prophylaxis had any effects on survival and rate of progression of fjord migrating Atlantic salmon post-smolts compared to control fish. Atlantic salmon spent on average only 151.2 h (maximum 207.3 h) in passing the 80 km fjord system and had, thus, entered the ocean when the more pathogenic pre-adult and adult lice stages developed. The brown trout, in comparison to Atlantic salmon, remained to a larger extent than Atlantic salmon in the inner part of the fjord system. No effect of salmon lice infection, or protection, was found in brown trout during the first weeks of their fjord migration. Brown trout will, to a larger extent than Atlantic salmon, stay in the fjord areas when salmon lice infections reach the more pathogenic pre-adult and adult stages. In contrast to Atlantic salmon, they will thereby possess the practical capability of returning to freshwater when encountering severe salmon lice attacks.


Salmo salar Salmo trutta Telemetry Salmon lice Migration Aquaculture 


  1. Berg, O. K. & M. Berg, 1987. Migrations of sea trout, Salmo trutta L., from the Vardnes river in northern Norway. Journal of Fish Biology 31: 113–121.CrossRefGoogle Scholar
  2. Berg, O. K. & B. Jonsson, 1990. Growth and survival rates of the anadromous trout, Salmo trutta, from the Vardnes River northern Norway. Environmental Biology of Fishes 29: 145–154.CrossRefGoogle Scholar
  3. Bjørn, P. A. & B. Finstad, 1997. The physiological effects of salmon lice infection on sea trout post smolts. Nordic Journal of Freshwater Research 73: 60–72.Google Scholar
  4. Bjørn, P. A., B. Finstad & R. Kristoffersen, 2001. Salmon lice infection of wild sea trout an Artic char in marine and freshwaters: the effects of salmon farms. Aquaculture Research 32: 947–962.CrossRefGoogle Scholar
  5. Boxaspen, K. & T. Næss, 2000. Development of eggs and planktonic stages of salmon lice (Lepeophtheirus salmonis) at low temperatures. Contributions to Zoology 69: 51–55.Google Scholar
  6. Bush, A. O., K. D. Lafferty, J. M. Lotz & A. Shostak, 1997. Parasitology meets ecology on its own terms: Margolis et al. revisited. Journal of Parasitology 83: 575–583.PubMedCrossRefGoogle Scholar
  7. Butler, J. R. A., 2002. Wild salmonids and sea lice infestation on the west coast of Scotland: sources of infection and implications for the management of marine salmon farms. Pest Management Science 58: 595–608.PubMedCrossRefGoogle Scholar
  8. Finstad, B., P. A. Bjørn, A. Grimnes & N. A. Hvidsten, 2000. Laboratory and field investigations of salmon lice [Lepeophtheirus salmonis (Krøyer)] infestation on Atlantic salmon (Salmo salar L.) post-smolts. Aquaculture Research 31: 795–803.CrossRefGoogle Scholar
  9. Finstad, B., F. Økland, E. B. Thorstad, P. A. Bjørn & R. S. McKinley, 2005. Migration of hatchery-reared Atlantic salmon and wild anadromous brown trout post-smolts in a Norwegian fjord system. Journal of Fish Biology 66: 86–96.CrossRefGoogle Scholar
  10. Gargan, P. G., O. Tully & W. R. Poole, 2003. Relationship between sea lice infestation, sea lice production and sea trout survival in Ireland, 1992–2001. In Mills, D (ed.), Salmon at the Edge. Blackwell Science, Oxford, pp. 119–135.Google Scholar
  11. Glover, K. A., Ø. Skaala, F. Nilsen, R. Olsen, A. J. Teale & J. B. Taggart, 2003. Different susceptibility of anadromous brown trout (Salmo trutta L.) populations to salmon louse (Lepeophtheirus salmonis (Krøyer, 1837)) infection. ICES Journal of Marine Science 60: 1139–1148.CrossRefGoogle Scholar
  12. Hansen, L. P., M. Holm, J. C. Holst & J. A. Jacobsen, 2003. The ecology of post-smolts of Atlantic salmon. In D. Mills (ed.), Salmon at the Edge. Blackwell Science, Oxford, pp. 25–39.Google Scholar
  13. Heuch, P. A., P. A. Bjørn, B. Finstad, J. C. Holst, L. Asplin & Nilsen, F., 2005. A review of the Norwegian ‘National action plan against salmon lice on salmonids’: the effect on wild salmonids. Aquaculture 246: 79–92.CrossRefGoogle Scholar
  14. Holst, J. C., P. Jacobsen, F. Nilsen, M. Holm, L. Asplin & J. Aure, 2003. Mortality of seaward-migrating post-smolts of Atlantic salmon due to salmon lice infection in Norwegian salmon stocks. In D. Mills (ed.), Salmon at the Edge. Blackwell Science, Oxford, pp. 136–137.Google Scholar
  15. Johnson, S. C. & L. J. Albright, 1991. Development, growth and survival of Lepeophtheirus salmonis (Copepoda: caligidae) under laboratory conditions. Journal of the Marine Biological Association of the United Kingdom 71: 425–436.CrossRefGoogle Scholar
  16. Klemetsen, A., P.-A. Amundsen, J. B. Dempson, B. Jonsson, N. Jonsson, M. F. O’Connell & E. Mortensen, 2003. Atlantic salmon Salmo salar L., brown trout Salmo trutta L. and Artic charr Salvelinus alpinius (L.): a review of aspects of their life histories. Ecology of Freshwater Fish 12: 1–59.CrossRefGoogle Scholar
  17. Knutsen, J. A., H. Knutsen, J. Gjøsæter & B. Jonsson, 2001. Food of anadromous brown trout at sea. Journal of Fish Biology 59: 533–543.CrossRefGoogle Scholar
  18. Lyse, A. A., S. O. Stefansson & A. Fernö, 1998. Behaviour and diet of sea trout post-smolts in a Norwegian fjord system. Journal of Fish Biology 52: 923–936.CrossRefGoogle Scholar
  19. Nolan, D. T., P. Reilly & S. E. Wendelaar Bonga, 1999. Infection with low numbers of the sea louse Lepeophtheirus salmonis induces stress-related effects in post-smolt Atlantic salmon (Salmo salar). Canadian Journal of Fisheries and Aquatic Sciences 56: 947–959.CrossRefGoogle Scholar
  20. Rikardsen, A. H., 2004. Seasonal occurrence of sea lice Lepeophtheirus salmonis on sea trout in two north Norwegian fjords. Journal of Fish Biology 65: 711–722.CrossRefGoogle Scholar
  21. Thorstad, E. B., F. Økland, B. Finstad, R. Sivertsgård, P. A. Bjørn & R. S. McKinley, 2004. Migration speeds and orientation of Atlantic salmon and sea trout post-smolts in a Norwegian fjord system. Environmental Biology of Fishes 71: 305–311.CrossRefGoogle Scholar
  22. Thorstad, E. B., F. Økland, B. Finstad, R. Sivertsgård, N. Plantalech, P. A. Bjørn & R. S. McKinley, 2007. Fjord migration and survival of wild and hatchery-reared Atlantic salmon and wild brown trout post-smolts. Hydrobiologia 582: 99–107.Google Scholar
  23. Tully, O. & D. T. Nolan, 2002. A review of population biology and host-parasite interactions of the sea lice Lepeophtheirus salmonis (Copepoda: Caligidae). Parasitology 124: 165–182.CrossRefGoogle Scholar
  24. Tully, O., P. Gargan, W. R. Poole & K. F. Whelan, 1999. Spatial and temporal variation in the infestation of sea trout (Salmo trutta L.) by the caligid copepod Lepeophtheirus salmonis (Krøyer) in relation to sources of infection in Ireland. Parasitology 119: 41–51.PubMedCrossRefGoogle Scholar
  25. Wagner, G. N., R. S. McKinley, P. A. Bjørn & B. Finstad, 2003. Physiological impact of sea lice on swimming performance of Atlantic salmon. Journal of Fish Biology 62: 1000–1009.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  • Rolf Sivertsgård
    • 1
  • Eva B. Thorstad
    • 2
  • Finn Økland
    • 2
  • Bengt Finstad
    • 2
  • Pål Arne Bjørn
    • 3
  • Niels Jepsen
    • 4
  • Trude Nordal
    • 2
  • R. Scott McKinley
    • 5
  1. 1.Norwegian College of Fishery ScienceUniversity of TromsøTromsøNorway
  2. 2.Norwegian Institute for Nature Research (NINA)TrondheimNorway
  3. 3.Norwegian Institute of Fisheries and Aquaculture ResearchTromsøNorway
  4. 4.Department of Inland FisheriesDanish Institute for Fisheries ResearchSilkeborgDenmark
  5. 5.West Vancouver LaboratoryThe University of British ColumbiaVancouverCanada

Personalised recommendations