Blar i Brage IMR på forfatter "Dempster, Tim"
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In situ sea lice egg sterilization with UVC light
Bui, Samantha; Oppedal, Frode; Barrett, Luke; Dempster, Tim; Pert, Cassie (Rapport fra havforskningen;2019 - 29, Research report, 2019)Sea-cage salmon farming creates ideal conditions for population growth of the salmon louse Lepeophtheirus salmonis, potentially leading to poor welfare and mortality in farmed salmon and nearby wild salmonids. Frequent ... -
Oxygen gradients affect behaviour of caged Atlantic salmon Salmo salar
Oldham, Tina; Dempster, Tim; Fosse, Jan Olav; Oppedal, Frode (Peer reviewed; Journal article, 2017)Dissolved oxygen (DO) conditions in marine aquaculture cages are heterogeneous and fluctuate rapidly. Here, by temporarily wrapping a tarpaulin around the top 0 to 6 m of a marine cage (~2000 m3), we manipulated DO to ... -
Prevention not cure: a review of methods to avoid sea lice infestations in salmon 1 aquaculture
Barrett, Luke T.; Oppedal, Frode; Robinson, Nicholas Andrew; Dempster, Tim (Peer reviewed; Journal article, 2020)The Atlantic salmon aquaculture industry still struggles with ectoparasitic sea lice despite decades of research and development invested into louse removal methods. In contrast, methods to prevent infestations before they ... -
Salmon lice treatments and salmon mortality in Norwegian aquaculture: a review
Overton, Kathy; Dempster, Tim; Oppedal, Frode; Kristiansen, Tore S; Gismervik, Kristine; Stien, Lars Helge (Journal article; Peer reviewed, 2018)With the expansion of Atlantic salmon aquaculture, the economic and ecological impacts of salmon lice (Lepeophtheirus salmonis) has increased. Norway battles this problematic parasite with various control and preventative ... -
Sentinels in Salmon Aquaculture: Heart Rates Across Seasons and During Crowding Events
Warren-Myers, Fletcher; Hvas, Malthe; Vågseth, Tone; Dempster, Tim; Oppedal, Frode (Peer reviewed; Journal article, 2021)Advances in tag technology now make it possible to monitor the behavior of small groups of individual fish as bioindicators of population wellbeing in commercial aquaculture settings. For example, tags may detect unusual ... -
Snorkelmerd: Produksjonseffektivitet, adferd og velferd. Sluttrapport FHF-prosjekt 900884
Oppedal, Frode; Dempster, Tim; Stien, Lars Helge (Rapport fra Havforskningen;9-2016, Research report, 2016-02)English: The snorkel cage creates a mismatch between the salmon lice infestative larvae stage and the salmon, thus minimizing infestations. The snorkel cages comprise a roof of net to keep the fish down, but with a tarpaulin ... -
Stable isotope marking of otoliths during vaccination: a novel method for mass-marking fish
Warren-Myers, Fletcher; Dempster, Tim; Fjelldal, Per Gunnar; Hansen, Tom; Jensen, Arne J.; Swearer, Stephen E. (Journal article; Peer reviewed, 2014-06-04)Tagging or marking of fishes enables the collection of population-based information for ecological research, yet few techniques enable 100% mark detection success. We tested a new mass-marking technique: otolith marking ... -
Submerged cage aquaculture of marine fish: a review of the biological challenges and opportunities
Sievers, Michael; Korsøen, Øyvind Johan; Warren-Myers, Fletcher; Oppedal, Frode; Macauley, Georgia; Folkedal, Ole; Dempster, Tim (Peer reviewed; Journal article, 2021)Surface-based cages are the dominant production technology for the marine finfish aquaculture industry. However, issues such as extreme weather events, poor environmental conditions, interactions with parasites, and conflicts ... -
Tag use to monitor fish behaviour in aquaculture: a review of benefits, problems and solutions
Macaulay, Georgia; Warren-Myers, Fletcher; Barrett, Luke T.; Oppedal, Frode; Føre, Martin; Dempster, Tim (Peer reviewed; Journal article, 2021)A variety of tagging techniques are now available to monitor fish behaviour, physiology and their environmental experience. Tagging is frequently used in aquaculture research to monitor free-swimming individuals within ... -
Torskeoppdrett i nedsenkede merder?
Korsøen, Øyvind Johan; Fosseidengen, Jan Erik; Dempster, Tim; Kristiansen, Tore S. (Journal article, 2011-05)På grunn av torskens forkjærlighet for lavere sommertemperaturer og høyere vintertemperaturer enn det man ofte finner i de øverste lagene i vannsøylen, har både kommersielle aktører og forskere forsøkt med oppdrett av ... -
Towards cod without spawning: artificial continuous light in submerged sea-cages maintains growth and delays sexual maturation for farmed Atlantic cod Gadus morhua
Korsøen, Øyvind Johan; Dempster, Tim; Fosseidengen, Jan Erik; Karlsen, Ørjan; Oppedal, Frode; Stien, Lars Helge; Kristiansen, Tore S. (Journal article; Peer reviewed, 2013-06-04)Sexual maturation and spawning in sea-cages is a major production and environmental challenge for the Atlantic cod farming industry. Altered photoperiod has arrested sexual maturation in cod kept in indoor or covered ...