Blar i SINTEF Open på forfatter "Alfredsen, Jo Arve"
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Biomonitoring using tagged sentinel fish and acoustic telemetry in commercial salmon aquaculture: A feasibility study
Føre, Martin; Frank, Kevin; Dempster, T; Alfredsen, Jo Arve; Høy, Erik (Journal article; Peer reviewed, 2017-08)We tested if it is technically feasible to monitor fish in real-time in full-scale commercial fish farms using acoustic telemetry. 31 Atlantic salmon were equipped with acoustic transmitter tags containing depth sensors. ... -
Characteristic current flow through a stocked conical sea-cage with permeable lice shielding skirt
Jonsdottir, Kristbjørg Edda; Pascal, Klebert; Volent, Zsolt; Alfredsen, Jo Arve (Peer reviewed; Journal article, 2021)The characteristic current flow field around a 55 m deep full-scale stocked conical Atlantic salmon sea-cage equipped with a 10 m permeable skirt was studied experimentally using acoustic Doppler velocimeters and profilers. ... -
Feed intake in Atlantic salmon fed with or without surface spreading of feed
Aas, Turid Synnøve; Ytrestøyl, Trine; Åsgård, Torbjørn Einar; Skøien, Kristoffer Rist; Alver, Morten Omholt; Alfredsen, Jo Arve (Journal article, 2020)In intensive salmon farming, it is common practice to spread the feed over a large surface area, assuming that spreading of the feed increases feed intake in the fish. However, the impact on the feed pellets during spreading ... -
Fish welfare based classification method of ocean current speeds at aquaculture sites
Jónsdóttir, Kristbjörg Edda; Hvas, Malthe; Alfredsen, Jo Arve; Føre, Martin; Alver, Morten; Bjelland, Hans Vanhauwaert; Oppedal, Frode (Journal article; Peer reviewed, 2019-06-06)A major trend in marine aquaculture is to move production to more exposed sites with occasionally rough ocean current events. However, it is unclear whether fish will thrive in these extreme environments, since thorough ... -
Heart rate and swimming activity as stress indicators for Atlantic salmon (Salmo salar)
Svendsen, Eirik; Føre, Martin; Økland, Finn; Gräns, Albin; Hedger, Richard David; Alfredsen, Jo Arve; Uglem, Ingebrigt; Rosten, Carolyn; Frank, Kevin; Erikson, Ulf Gøran; Finstad, Bengt (Journal article; Peer reviewed, 2021-01-30)We investigated the relationship between telemetry measurements of heart rate and swimming activity and the physiological status in farmed Atlantic salmon (Salmo salar) to assess the potential to use telemetry measurements ... -
Modelling and simulation of rotary feed spreaders with application to sea cage aquaculture ? A study of common and alternative designs
Skøien, Kristoffer Rist; Alver, Morten; Alfredsen, Jo Arve (Journal article; Peer reviewed, 2018-08)Rotary feed spreaders are extensively used in large scale fish aquaculture and are tasked with distributing pelletized feed in a spatially uniform manner over the water surface. Questions have been raised with respect to ... -
Modelling how the physical scale of experimental tanks affects salmon growth performance
Føre, Martin; Alver, Morten; Alfredsen, Jo Arve; Senneset, Gunnar; Espmark, Åsa Maria Olofsdotter; Terjesen, Bendik Fyhn (Journal article; Peer reviewed, 2018-10-01)In this study, we explored the potential of using mathematical models for studying the effects of physical scale of production units on the growth performance of Atlantic salmon (Salmo salar L.). Atlantic salmon are typically ... -
Optical measurement of tissue perfusion changes as an alternative to electrocardiography for heart rate monitoring in Atlantic salmon (Salmo salar)
Svendsen, Eirik; Økland, Finn; Føre, Martin; Randeberg, Lise Lyngsnes; Finstad, Bengt; Olsen, Rolf Erik; Alfredsen, Jo Arve (Peer reviewed; Journal article, 2021)Background: Welfare challenges in salmon farming highlights the need to improve understanding of the fish’s response to its environment and rearing operations. This can be achieved by monitoring physiological responses ... -
Precision fish farming: A new framework to improve production in aquaculture
Føre, Martin; Frank, Kevin; Norton, Tomas; Svendsen, Eirik; Alfredsen, Jo Arve; Dempster, Timothy David; Eguiraun, Harkaitz; Watson, Win; Stahl, Annette; Sunde, Leif Magne; Schellewald, Christian; Skøien, Kristoffer Rist; Alver, Morten; Berckmans, Daniel (Journal article; Peer reviewed, 2017-11-14)Aquaculture production of finfish has seen rapid growth in production volume and economic yield over the last decades, and is today a key provider of seafood. As the scale of production increases, so does the likelihood ... -
Using acoustic telemetry to monitor the effects of crowding and delousing procedures on farmed Atlantic salmon (Salmo salar)
Føre, Martin; Svendsen, Eirik; Alfredsen, Jo Arve; Uglem, Ingebrigt; Bloecher, Nina; Sveier, Harald; Sunde, Leif Magne; Frank, Kevin (Journal article; Peer reviewed, 2018-10-01)The aim of this study was to demonstrate the feasibility of acoustic telemetry for monitoring fish during farm operations and gather knowledge about Atlantic salmon responses during crowding and delousing events in a ...