Background and activities

My work

I am writing a PhD on salmon lice. Chemotherapeutants were long the main tool to combat salmon lice in aquaculture, but after a while the lice became resistant. The genetic markers for two of the compounds, organophosphates and pyrethroids, are known, which enables us to find resistant lice by using a genetic test. I use the genetic markers to investigate how reistance disperse in time and space in the North Atlantic salmon louse population, where also wild Atlantic salmon and sea trout play a role.

I also contribute on other research projects at the institute that involves salmon lice, wild salmonids or aquaculture. I supervise bachelor students.


  • Salmon lice
  • Interactions between farmed and wild salmonids
  • Wild Atlantic salmon and sea trout



  • Bachelor in Ecology and natural resource management, Norwegian University of Life Sciences
  • Master in Naturasl resource management, Norwegian University of Life Sciences

Work experience:

  • Manager of Geiranger-Herdalen protected landscape

Scientific, academic and artistic work

A selection of recent journal publications, artistic productions, books, including book and report excerpts. See all publications in the database

Journal publications

Part of book/report

  • Fjørtoft, Helene Børretzen; Tveten, Ann-Kristin; Stene, Anne. (2018) Screening for viruses in salmonids from a rotenone-treated Norwegian river. Blue Growth: Aquaculture, Fisheries, Market and Health Perspectives..
  • Tveten, Ann-Kristin; Fjørtoft, Helene Børretzen; Olsen, Magne Hauge; Venås, Leonardo Areas; Isaksson, Aimee Kathrina Soto. (2015) Fargemetoder for prøvepreparering ved histologiske undersøkelser og fluoresense in situ hybridisering for studier av amøbegjellesykdom (AGD) i gjellevev og lakselus. Blue Bio-resources.