20 research outputs found

    En mulighetsstudie for økt vekst innen innlandsoppdrett

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    SINTEF Fiskeri og havbruk har sammen med Bioforsk Nord og Nofuna Marked gjennomført en vurdering av mulighetene for økt vekst innen innlandsoppdrett i Norge. Følgende arter er vurdert: Røye, ørret, sik, regnbueørret, gjørs, abbor og lake. Studien gir en oversikt over innlandsoppdrett i Norge og i andre nordiske land. Mulighetene for utvikling av en innlandsoppdrettsnæring i Norge er ellers vurdert ut fra status og potensial innen produkt og marked, biologiske forhold, ressursbruk og miljøeffekter, teknologi samt forretningsmessige forhold. FoU-behovet er beskrevet og prioritert på grunnlag av vurderingene av status og potensialpublishedVersio

    En mulighetsstudie for økt vekst innen innlandsoppdrett

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    Source at http://hdl.handle.net/11250/2482490SINTEF Fiskeri og havbruk har sammen med Bioforsk Nord og Nofuna Marked gjennomført en vurdering av mulighetene for økt vekst innen innlandsoppdrett i Norge. Følgende arter er vurdert: Røye, ørret, sik, regnbueørret, gjørs, abbor og lake. Studien gir en oversikt over innlandsoppdrett i Norge og i andre nordiske land. Mulighetene for utvikling av en innlandsoppdrettsnæring i Norge er ellers vurdert ut fra status og potensial innen produkt og marked, biologiske forhold, ressursbruk og miljøeffekter, teknologi samt forretningsmessige forhold. FoU-behovet er beskrevet og prioritert på grunnlag av vurderingene av status og potensia

    The influence of a stimulated transportation of newly fertilized Atlantic salmon eggs on mortality to the eyed stage

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    Transport of newly fertilized eggs has often resulted in severe mortality of the eggs during incubation to the eyed stage. To investigate the effect of transport on mortality, pooled eggs from several females were handled through a simulated transportation experiment after fertilization and swelling. Egg groups handled in different ways and duration were incubated separately to the eyed stage and mortality was registered. The results showed variable mortality figures but there was increased mortality for egg groups handled for a longer period after fertilization. The mortality also seemed dependent upon how the eggs were handled. The reasons to mortality as a result of handling is not known and more work is needed to investigate this

    Aluminium accumulation on eggs and hatching system during the incubation period - an important cause of variable hatching success ?

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    Groups of rainbow trout eggs were incubated in duplicate in trays with PVC screens and original aluminium screens. During incubation aluminium bound to sediments was deposited on eggs and hatching systems. By adding acid the pH of the inlet water to a PVC hatching system with sediments from the hatchery water in it, was experimentaly lowered. Buffering of the outlet water was observed from pH 5.0 and lower, and at pH 4.5 and lower an increase of aluminium concentration in outlet water was measured. If a variable pH of the hatchery water is to be expected, the aluminiumrich sediments deposited on eggs and hatching system during incubation may represent a threat to the survival of eggs and fry

    Effects of different rearing environments on the mortality of Atlantic salmon broodstock and eggs

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    Atlantic salmon (Salmo salar) reared for three years in seawater were moved to brackish- and freshwater before they matured. A control group matured in seawater. The groups were given different feeding regimes the last months before maturation. Mortality of maturing and stripped broodfish was lower in both the brackish and freshwater than that in seawater. Eggs stripped from fresh- or brackish water showed significant lower mortalities to the eyed stage than eggs stripped from seawater. There was no significant differences in mortality to the eyed stage between groups of eggs stripped from brackish and fresh water. Starvation of Atlantic salmon broodstock four months prior to spawning did not seem to adversely affect egg quality

    pH adjustment of acid water at Matre Aquaculture Station: Experiences with previous and existing methods

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    The water from Matre River is characterized as very soft, with a total hardness of 1. 5 - 2. 5 mg Ca0/1 and a very low buffer capacity. Acid precipitation results in low pH, values below 5. 0 are recorded every year. As a consequence of the water quality, several systems for pH adjustment has been tried, most of them having evident limitations. In this paper several of them has been described and evaluated. A special attention has been put on the two systems which at the moment are beeing used at the station and which we think are holding promise. These are the neutralizing systems based on the addition of sodium hydroxide and well pumped salt water

    Overgang til lukkede oppdrettsanlegg i sjø - teoretisk beregning av endret arealbehov

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    Norge har et stort sjøareal innenfor territorialgrensen som tilsvarer 45 prosent av Norges landareal. Likevel er det kamp om arealene og da spesielt i de kystnære områdene. Fra enkelte hold har det kommet synpunkter på at oppdrettsnæringen må ta i bruk lukkede systemer for oppdrett av fisk i sjø. Dagens tilgjengelige typer av lukkede anlegg for oppdrett i sjø innehar i stor grad et mye lavere tilgjengelig oppdrettsvolum enn dagens åpne oppdrettssystemer med flytekrage med not. Et tenkt scenario med flytting av hele den norske oppdrettsproduksjonen av laks og ørret til lukkede flytende anlegg, vil derfor kreve en betydelig økning i antall oppdrettsenheter, gitt dagens forvaltningsregime. Areal behovet med lukkede anlegg reduseres dersom høyere fisketetthet og større enheter muliggjøres. Artikkelen bygger på en forstudie utført av en forskergruppe fra SINTEF, Nofima og Veterinærinstituttet på vegne av Fiskeri- og havbruksnæringens forskingsfond i 2011.publishedVersio
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