Tonje Knutsen Sørdalen

Ph.D. Candidate

Institute of Marine Research
Marine Ecosystem Acoustics Group
Flødevigen Research Station
Nye Flødevigveien 20, 4817 His, NORWAY
Tel. 93627433
Email: tonjes@imr.no

See my profile on Research Gate
See my profile on Google Scholar

Education

Ph.D. candidate (present) in Marine Biology, University of Oslo (Norway)
M.Sc. (2012) in Marine ecology, Norwegian University of Life Sciences (NMBU)
B.Sc. (2011) in Biology, Norwegian University of Life Sciences (NMBU)
B.Sc. (2005) in Political sciences, Norwegian University of Science and Technology (NTNU)

Areas of expertise and interest

I am a marine ecologist interested in anthropogenic influence on reproductive behavior, population dynamics and contemporary evolution in crustaceans and fish. My main approach involves combining genetic methods and field studies of behavior and life history traits to understand the eco-evolutionary consequences of different management strategies and harvesting practices. I’m currently involved in studies addressing the sustainability in harvesting wrasse species for the use as cleaner fish in salmonid aquaculture. We use mark-recapture data from in and outside marine reserves, otolith analysis and sea data to investigate how behavior of fish and fishermen relate to one another, and how populations change due to selection. I am also in the final stage of completing my PhD where I study how the fishery interacts with the European lobsters’ population dynamic, and how it affects sexual selection, reproductive strategies and mate choice.

Active projects

Population dynamics of wild wrasse populations along the Norwegian coast (led by Anne Berit Skiftesvik)

Publications

Sex- and size-selective harvesting of corkwing wrasse (Symphodus melops) cleaner fish in salmonid aquaculture.

Halvorsen, K.T., T.K. Sørdalen, L.A. Vøllestad, A.B. Skiftesvik, S.H. Espeland & E.M. Olsen. 2017. Sex- and size-selective harvesting of corkwing wrasse (Symphodus melops) cleaner fish in salmonid aquaculture. ICES Journal of Marine Science 74: 660-669.
Read the paper

Impact of harvesting cleaner fish for salmonid aquaculture assessed from replicated coastal marine protected areas.

Halvorsen, K.T., T. Larsen, T. K.Sørdalen, L.A. Vøllestad, H. Knutsen & E.M. Olsen. 2017. Impact of harvesting cleaner fish for salmonid aquaculture assessed from replicated coastal marine protected areas. Marine Biology Research 13: 359-369.
Read the paper

Male biased sexual size dimorphism in the nest building corkwing wrasse (Symphodus melops): implications for a size regulated fishery.

Halvorsen, K.T., T.K. Sørdalen, C.M.F. Durif, H. Knutsen, E.M. Olsen, A.B. Skiftesvik, T.E. Rustand, R.M. Bjelland & L.A. Vøllestad. 2016. Male biased sexual size dimorphism in the nest building corkwing wrasse (Symphodus melops): implications for a size regulated fishery. ICES Journal of Marine Science 73: 2586-2594.
Read the paper

Genotype reconstruction of paternity in European lobsters (Homarus gammarus).

Ellis, C. D., Hodgson, D. J., André, C., Sørdalen, T. K., Knutsen, H., & Griffiths, A. G. F. 2015. Genotype reconstruction of paternity in European lobsters (Homarus gammarus). PLoS ONE 10: 1–14.
Read the paper

Size selective harvesting and sexual selection in the European lobster

Sørdalen, T.K., Halvorsen, K.T, Harrison, H., Ellis, C., Vøllestad, L.A., Moland, E., Knutsen, H. & Olsen, E.M. Size selective harvesting and sexual selection in the European lobster. (in prep.).

Rapid population-level responses in sex ratio, but not in catch rate after protection of egg-bearing lobster (Homarus gammarus)

Sørdalen, T.K., Halvorsen, K.T & Olsen, E.M. et al. Rapid population-level responses in sex ratio, but not in catch rate after protection of egg-bearing lobster (Homarus gammarus) (in prep.).

Maternal effects in European lobster (Homarus gammarus) inside and outside marine reserves

Sørdalen, T.K., Halvorsen, K.T & Olsen, E.M. et al. Maternal effects in European lobster (Homarus gammarus) inside and outside marine reserves (in prep.).

Last updated: November 6, 2017