Kim T. Halvorsen

Research Scientist

Institute of Marine Research
Acoustics and Observation Methodologies Research Group
Flødevigen Research Station
Nye Flødevigveien 20
4817 His, NORWAY
Tel. 47 40 01 66 01
Email: kim.halvorsen@imr.no

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Education

Ph.D. (2017) in Marine Biology, University of Oslo
M.Sc. (2010) in Sustainable Coastal Development, Norwegian University of Science and Technology
B.Sc. (2008) in Biology, Norwegian University of Science and Technology

Areas of expertise and interest

My main interest is how fisheries and other human activities interact with species’ life history traits, behaviour and reproductive biology in an integrated ecological and evolutionary perspective. In this context, most of my previous and current research is conducted on different wrasse species commercially harvested and used as cleaner fish in salmonid aquaculture. This involves field investigations, otolith analyses and mark-recapture studies in and outside marine protected areas. Moreover, I’m involved in studies of the effects of fishing on sexual selection and sex-ratios in European lobster using genetic parentage assignment. During my masters I studied evolution, biogeography and population genetics of gadids.

Active projects

  • Computer vision to expand monitoring and accelerate assessment of coastal fish (COASTVISION)
  • Population dynamics of wild wrasse populations along the Norwegian coast

Publications

Trajectory-based fish event classification through pre-training with diffusion models

Canovi, N., B.A. Ellis, T.K. Sørdalen, V. Allken, K.T. Halvorsen, K. Malde, & C. Beyan. 2024. Trajectory-based fish event classification through pre-training with diffusion models. Ecological Informatics. doi: 10.1016/j.ecoinf.2024.102733.
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A new maximum age observed within the family Labridae, Ballan wrasse Labrus bergylta

Pritchard, C.J., M.M.R Stendal, R. Treasurer, K.T. Halvorsen & A.B. Skiftesvik. 2024. A new maximum age observed within the family Labridae, Ballan wrasse Labrus bergylta. Journal of Fish Biology. doi: 10.1002/JFB.15886.
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Fishing and use of cleaner fish in Norwegian farming – status of knowledge

Sandlund, N., K. Halvorsen, E. Jansson, K. Nedreaas, S. Guidos, M.M.R. Stendal, T. Jørgensen & A.B. SKiftesvik. 2024. Fishing and use of cleaner fish in Norwegian farming – status of knowledge. Institute of Marine Research, report series: 2024-31. ISSN: 1893-4536. (In Norwegian with summary in English)
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Global, regional, and cryptic population structure in a high gene-flow transatlantic fish

Jansson, E., E. Faust, D. Bekkevold, M. Quintela, C. Durif, K.T. Halvorsen, G. Dahle, C. Pampoulie, J. Kennedy, B. Whittaker, L. Unneland, S. Post, C. André & K. A. Glover. 2023. Global, regional, and cryptic population structure in a high gene-flow transatlantic fish. PLOS ONE. doi: 10.1371/journal.pone.0283351.
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Genetic study reveals local differentiation persisting in the face of high connectivity and a genomic inversion likely linked with sexual antagonism in a common marine fish

Jansson, E. C. André, M. Quintela, K.T. Halvorsen, F. Besnier, F. Ayllon, E. Faust, H. Knutsen, Å. Strand, K.A. Glover. 2023. Genetic study reveals local differentiation persisting in the face of high connectivity and a genomic inversion likely linked with sexual antagonism in a common marine fish. ICES Journal of Marine Science. doi: 10.1093/icesjms/fsad042.
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A contrastive learning approach for individual re-identification in a wild fish population

Langøy Olsen, Ø., T. Knutsen Sørdalen, M. Goodwin, K. Malde, K. Muri Knausgård & K.T. Halvorsen 2023. A contrastive learning approach for individual re-identification in a wild fish population. Proceedings of the Northern Lights Deep Learning Workshop 4, doi: 10.7557/18.6824.
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Protection from fishing improves body growth of an exploited species

Sørdalen, T.K., Halvorsen K.T. & E.M. Olsen. 2022. Protection from fishing improves body growth of an exploited species. Proceeding of the Royal Society B: Biological Sciences. doi: 10.1098/rspb.2022.1718.
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Read stories about the work in The Economist, Nature, and HERE (in Norwegian)

Unlocking the potential of deep learning for marine ecology: overview, applications, and outlook

Goodwin, Morten, Halvorsen, Kim, Jiao, Lei, Knausgård, Kristian Muri, Martin, Angela, Moyano, Marta, Oomen, Rebekah A., Rasmussen, Jeppe, Sørdalen, Tonje Knutsen, Thorbjørnsen, Susanna Huneide. 2022. Unlocking the potential of deep learning for marine ecology: overview, applications, and outlook. ICES Journal of Marine Science. doi:10.1093/icesjms/fsab255.
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Lobster reserves as a management tool in coastal waters: two decades of experience in Norway

Knutsen, J.A., A.R. Kleiven, E.M Olsen, H. Knutsen, S.H. Espeland, T.K. Sørdalen, S.H. Thorbjørnsen, J.A. Hutchings, A. Fernández-Chacón, M. Huserbråten, D. Villegas-Ríos, K.T. Halvorsen, P.J Kleiven, T.K. Langeland & E. Moland. 2022. Lobster reserves as a management tool in coastal waters: two decades of experience in Norway. Marine Policy 136: February 2022, 104908.
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Highly mixed impacts of near-future climate change on stock productivity proxies in the North East Atlantic

Kjesbu, O.S. and 42 other authors, including C.M.F. Durif and K. Halvorsen. 2022. Highly mixed impacts of near-future climate change on stock productivity proxies in the North East Atlantic. Fish and Fisheries. doi: 10.1111/faf.12635.
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Goldsinny wrasse (Ctenolabrus rupestris) have a sex-dependent magnetic compass for maintaining site fidelity

Cresci, A., T. Larsen, K.T. Halvorsen, C.M.F. Durif, R.M. Bjelland, H.I. Browman & A.B. Skiftesvik. 2022. Goldsinny wrasse (Ctenolabrus rupestris) have a sex-dependent magnetic compass for maintaining site fidelity. Fisheries Oceanography 31: 164–171. doi: 10.1111/fog.12569.
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Read stories about the work HERE and HERE (in Norwegian)

Towards a sustainable fishery and use of cleaner fish in salmonid aquaculture

Halvorsen, K., A.B. Skiftesvik, C. Durif, E. Faust, H. Wennhage, C. André, J.L. Rønfeldt, P.R. Møller, H. Carl, T. Jørgensen, M. Quintela, N. Sandlund, L.H. Stien, K. Nedreaas, E. Jansson, H.H. Stockhausen, K. Korsnes, P. Reynolds, A. Imsland, I. Fyllingen, H. Bysheim, L. Henly & S. Mortensen. 2021. Towards a sustainable fishery and use of cleaner fish in salmonid
aquaculture. Challenges and opportunities. http://dx.doi.org/10.6027/temanord2021-545.
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Restoration of abundance and dynamics of coastal fish and lobster within northern marine protected areas across two decades

Moland, E., A. Fernández-Chacón, T.K. Sørdalen, D. Villegas-Ríos, S.H. Thorbjørnsen, K.T. Halvorsen, M. Huserbråten, E.M. Olsen, P.J. Nillos-Kleiven, A.R. Kleiven, H. Knutsen, S.H. Espeland, C. Freitas, J.A. Knutsen. 2021. Restoration of abundance and dynamics of coastal fish and lobster within northern marine protected areas across two decades. Frontiers in Marine Science. 8:674756. doi: 10.3389/fmars.2021.674756.
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Movement patterns of temperate wrasses (Labridae) within a small marine protected area

Halvorsen, K.T., T. Larsen, H.I. Browman, C.M.F. Durif, N. Aasen, L.A. Vøllestad, A. Cresci, T.K. Sørdalen, R. Bjelland & A.B. Skiftesvik. 2021. Movement patterns of temperate wrasses (Labridae) within a small marine protected area. Journal of Fish Biology. 99: 1513-1518. doi: 10.1111/jfb.14825.
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Temperate fish detection and classification: a deep learning based approach

Knausgård. K.M., Wiklund. A., Sørdalen T.K., Halvorsen K.T, Kleiven, A., Jiao, L. & M. Goodwin. 2021. Temperate fish detection and classification: a deep learning based approach. Applied Intelligence, doi: 10.1007/s10489-020-02154-9.
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Not that clean: aquaculture mediated translocation of cleaner fish has led to hybridization on the northern edge of the species’ range

Faust, E., E. Jansson, C. André, K.T. Halvorsen, G. Dahle, H. Knutsen, M. Quintela & K.A. Glover. 2021. Not that clean: aquaculture mediated translocation of cleaner fish has led to hybridization on the northern edge of the species’ range. Evolutionary Applications 10.1111/eva.13220.
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Mind the depth: The vertical dimension of a small-scale fishery shapes selection on species, size and sex in wrasses

Halvorsen, K.T., T. Knutsen Sørdalen, T. Larsen, H.I. Browman, T. Rafoss, J. Albretson & A.B. Skiftesvik. 2020. Mind the depth: The vertical dimension of a small-scale fishery shapes selection on species, size and sex in wrasses. Marine and Coastal Fisheries 12: 404–422, doi: 10.1002/mcf2.10131.
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The consequences of size-selective fishing mortality for larval production and sustainable yield in species with obligate male care

Kindsvater H.K., Halvorsen K.T., Sørdalen T.K. & S.H. Alonzo. 2020. The consequences of size-selective fishing mortality for larval production and sustainable yield in species with obligate male care. Fish and Fisheries. DOI: 10.1111/faf.12491
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“A cleaner break”: Genetic divergence between geographic groups and sympatric phenotypes revealed in ballan wrasse (Labrus bergylta)

Seljestad, G.W., M. Quintela E. Faust, K.T. Halvorsen, F. Besnier, E. Jansson, G. Dahle, H. Knutsen, C. Andre, A. Folkvord & K.A. Glover. 2020. “A cleaner break”: Genetic divergence between geographic groups and sympatric phenotypes revealed in ballan wrasse (Labrus bergylta). Ecology and Evolution 2020;00:1–16. doi: 10.1002/ece3.6404.
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Marine protected areas rescue a sexually selected trait in European lobster

Knutsen Sørdalen, T., K.T. Halvorsen, L.A. Vøllestad, E. Moland & E. Moland Olsen. 2020. Marine protected areas rescue a sexually selected trait in European lobster. Evolutionary Applications, doi: 10.1111/eva.12992.
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Assessment of the risk to Norwegian biodiversity from import of wrasses and other cleaner fish for use in aquaculture

VKM, E. Rueness, P.R. Berg, S. Gulla, K. Halvorsen, J. Järnegren, M. Malmstrøm, T.A. Mo, E. Rimstad, H. de Boer, K. Eldegard, K. Hindar, L.R. Hole, K. Kausrud, L. Kirkendall, I. Måren, E.B. Nilsen, E.B. Thorstad, A. Nielsen & G. Velle. 2019. Assessment of the risk to Norwegian biodiversity from import of wrasses and other cleaner fish for use in aquaculture. Opinion of the Panel on Alien Organisms and Trade in Endangered Species (CITES) of the Norwegian Scientific Committee for Food and Environment. VKM report 2019: 15, ISBN: 978-82-8259-330-4, ISSN: 2535-4019.
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Kunnskapsinnhenting Leppefisk – biologi og fiskeri 2013-2018

Skiftesvik, A.B., K. Halvorsen & T. Larsen. 2019. Kunnskapsinnhenting Leppefisk – biologi og fiskeri 2013-2018. Rapport fra Havforskningen 2019-18. ISSN:1893-4536
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Potential for managing life history diversity in a commercially exploited intermediate predator, the goldsinny wrasse (Ctenolabrus rupestris)

Olsen, E., K. Halvorsen, T. Larsen & A. Kuparinen. 2019. Potential for managing life history diversity in a commercially exploited intermediate predator, the goldsinny wrasse (Ctenolabrus rupestris). ICES Journal of Marine Science. doi:10.1093/icesjms/fsy183
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Cleaner fish escape salmon farms and hybridize with local wrasse populations

Faust, E., K.T. Halvorsen, P. Andersen, H. Knutsen, C. André. 2018. Cleaner fish escape salmon farms and hybridize with local wrasse populations. Royal Society Open Science 5: 171752. DOI: 10.1098/rsos.171752
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Harvesting changes mating behavior in European lobster

Sørdalen, T.K., K.T. Halvorsen, H.B. Harrison, C. Ellis, L.A. Vøllestad, H. Knutsen, E. Moland & E. Moland Olsen. 2018. Harvesting changes mating behavior in European lobster. Evolutionary Applications 11:963–977. DOI 10.1111/eva.12611
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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.
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Selective harvesting and life history variability of corkwing and goldsinny wrasse in Norway: Implications for management and conservation.

Halvorsen, K.T. 2017. Selective harvesting and life history variability of corkwing and goldsinny wrasse in Norway: Implications for management and conservation. PhD thesis. University of Oslo.
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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.
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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.
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Mitochondrial DNA differentiation between the antitropical blue whiting species Micromesistius poutassou and Micromesistius australis.

Halvorsen, K.T., E. Árnason, P.J. Smith & J. Mork. 2012. Mitochondrial DNA differentiation between the antitropical blue whiting species Micromesistius poutassou and Micromesistius australis. Journal of Fish Biology 81: 253-269
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Last updated: August 21, 2024