Browsing NTNU Open by Author "Fjørtoft, Helene Børretzen"
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Aquaculture-driven evolution of the salmon louse mtDNA genome
Rutle, Karoline Hasti; Skern-Mauritzen, Rasmus; Nilsen, Frank; Mateos-Rivera, Alejandro; Sørvik, Anne Grete Eide; Jansson, Eeva; Quintela, Maria; Besnier, Francois; Ayllon, Fernando; Fjørtoft, Helene Børretzen; Glover, Kevin Alan (Peer reviewed; Journal article, 2023)Resistance toward the antiparasitic pyrethroid, deltamethrin, is reported in the Atlantic salmon louse (Lepeophtheirus salmonis salmonis), a persistent ectoparasite of farmed and wild salmonids. The resistance mechanism ... -
Aquaculture-driven evolution: distribution of pyrethroid resistance in the salmon louse throughout the North Atlantic in the years 2000–2017
Fjørtoft, Helene Børretzen; Nilsen, Frank; Besnier, Francois; Espedal, Per Gunnar; Stene, Anne; Tveten, Ann-Kristin; Bjørn, Pål Arne; Aspehaug, Vidar; Glover, Kevin (Peer reviewed; Journal article, 2020)The parasitic salmon louse, and its documented resistance to chemotherapeutants, represents the most persistent environmental challenge to global salmonid aquaculture. We used a genetic marker associated with pyrethroid ... -
Considering elements of natural strategies to control salmon lice infestation in marine cage culture
Stene, Anne; Hellevik, Christina Carrozzo; Fjørtoft, Helene Børretzen; Philis, Gaspard (Peer reviewed; Journal article, 2022)Salmon lice are a severe problem in salmonid aquaculture and also affect wild salmon smolts migrating through fjord systems in spring. To keep the lice burden within acceptable limits, frequent use of chemical delousing ... -
Fargemetoder for prøvepreparering ved histologiske undersøkelser og fluoresense in situ hybridisering for studier av amøbegjellesykdom (AGD) i gjellevev og lakselus
Tveten, Ann-Kristin; Fjørtoft, Helene Børretzen; Olsen, Magne Hauge; Venås, Leonardo Areas; Isaksson, Aimee Kathrina Soto (Chapter, 2015)Målet med studien var å etablere god metoder for oppbevaring og fiksering av gjellevev og lakselus for patologiske studier. Oppbevaring av prøvemateriale over lengre perioder kan føre til at vevsstrukturen svekkes og vevet ... -
Losing the 'arms race': Multiresistant salmon lice are dispersed throughout the North Atlantic Ocean
Fjørtoft, Helene Børretzen; Nilsen, Frank; Besnier, Francois; Stene, Anne; Tveten, Ann-Kristin; Bjørn, Pål Arne; Aspehaug, Vidar Teis; Glover, Kevin Alan (Journal article; Peer reviewed, 2021)Nothing lasts forever, including the effect of chemicals aimed to control pests in food production. As old pesticides have been compromised by emerging resistance, new ones have been introduced and turned the odds back in ... -
Salmon lice sampled from wild Atlantic salmon and sea trout throughout Norway display high frequencies of the genotype Associated with pyrethroid resistance
Fjørtoft, Helene Børretzen; Nilsen, Frank; Besnier, Francois; Stene, Anne; Bjørn, Pål Arne; Tveten, Ann-Kristin; Aspehaug, Vidar Teis; Finstad, Bengt; Glover, Kevin (Journal article; Peer reviewed, 2019)Atlantic salmon Salmo salar aquaculture is based on the use of open-pen sea cages, with the consequence that farmed fish are both recipients and sources of pathogens from surrounding waters. Currently, the parasitic salmon ... -
Tap av areal for sjøørret (Salmo trutta) i elver og bekkar i Ålesund kommune
Hofseth, Steinar Lunde (Bachelor thesis, 2023)Samandrag Denne bacheloroppgåva kvantifiserer tapet av anadromt elveareal, innsjøareal og elvestrekning i 29 vassdrag i Ålesund kommune. Dagens tilstand er samanlikna med «original» tilstand, som vil seie den opphavelege ... -
The mechanism (Phe362Tyr mutation) behind resistance in Lepeophtheirus salmonis pre-dates organophosphate use in salmon farming
Kaur, Kiranpreet; Besnier, Francois; Glover, Kevin; Nilsen, Frank; Aspehaug, Vidar Teis; Fjørtoft, Helene Børretzen; Horsberg, Tor Einar (Journal article; Peer reviewed, 2017)The salmon louse is an ectoparasitic copepod of salmonids in the marine environment, and represents a global challenge to salmon aquaculture. A major issue is the reliance of the industry on a limited number of chemicals ... -
The Phe362Tyr mutation conveying resistance to organophosphates occurs in high frequencies in salmon lice collected from wild salmon and trout
Fjørtoft, Helene Børretzen; Besnier, Francois; Stene, Anne; Nilsen, Frank; Bjørn, Pål Arne; Tveten, Ann-Kristin; Finstad, Bengt; Aspehaug, Vidar; Glover, Kevin (Journal article; Peer reviewed, 2017)The parasitic salmon louse, and its resistance to chemical delousing agents, represents one of the largest challenges to the salmon aquaculture industry. We genotyped lice sampled from wild salmon and sea trout throughout ...