English
norskBlar i forfatter Artikler, rapporter og annet (Norges fiskerihøgskole) "Thorarensen, Helgi"
Viser treff 1-6 av 6
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A comparative study of the effects of pelleted and extruded feed on growth, financial revenue and nutrient loading of Nile tilapia (Oreochromis niloticus L.) cage culture in a lacustrine environment
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-05)We compared the benefits of using extruded feed (EF), against pelleted feed (PF) to guide cage culture investments in Great Lakes. Three out of six cages in the same farm had fish that were fed EF and the other half, belonging to a different farm had fish that were fed PF. The diets were similar in crude protein, lipid and energy content. However, the fiber content in PF was 4 times higher than that ... -
The effect of CO2, total ammonia nitrogen and pH on growth of juvenile lumpfish (Cyclopterus lumpus)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-12)The objective of this study was to examine the effects of CO<sub>2</sub>, total ammonia nitrogen (TAN: nitrogen bound as either NH<sub>3</sub> or NH<sub>4</sub><sup>+</sup>) and pH on the growth and survival of juvenile lumpfish in a two-month growth study. The results demonstrate the complex interactions of these water quality variables. The specific growth rate (SGR) of the lumpfish was progressively ... -
The effect of temperature on growth performance and aerobic metabolic scope in Arctic charr, Salvelinus alpinus (L.)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-06)In recent years, Arctic char populations in Iceland have declined and the objective of this experiment was to throw further light on these changes by examining the effect of temperature (5, 9, 13, 17, and 21 °C) on the survival, growth rate, metabolism, and physiological indices of juvenile Arctic charr (initial mean body mass 4.02 ± 0.8 g). Mortality was 60% at 21 °C while at lower temperatures it ... -
Impacts of Nile tilapia cage culture on water and bottom sediment quality: The ability of an eutrophic lake to absorb and dilute perturbations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-07)Environmentally sustainable aquaculture depends on accurate understanding of the impacts of aquaculture-derived organic matter (AOM) and the ability of aquaculture systems to absorb and dilute perturbations. To this end, the present study assessed the impacts of AOM from cage culture of Nile tilapia on the ecology of Lake Victoria, Kenya, using fish cages near Anyanga Beach in Siaya County from ... -
Intensive aquaculture and sustainable regional development in the Arctic region – from controversy to dialogue (AquaLog)
(Research report; Forskningsrapport, 2017-08-28)The main objective of the AquaLog project is to understand factors and forces that influence the aquaculture controversy in the Arctic communities. This report summarizes the second workshop in Vancouver, Canada 23-27th April 2017. The project is funded by the Nordic Council of Minister and the Norwegian Fram Centre. -
Wild and Farmed Arctic Charr as a Tourism Product in an Era of Climate Change
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-12)The topic investigated is the social-ecological system of Arctic charr (Salvelinus alpinus) fishing and aquaculture as a tourism product in an era of climate change. Arctic charr is a resilient salmonid species that was traditionally an important part of the sustenance economy in Arctic and Subarctic communities as a source of fresh food throughout the year. Arctic charr populations have declined ...
