English
norskBlar i forfatter "Halttunen, Elina"
Viser treff 1-10 av 10
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An effective method for the recapture of escaped farmed salmon
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011-04-04)The search for effective strategies to prevent and mitigate accidental releases of aquaculture fishes is on-going. To test a new recapture strategy and evaluate the individual dispersal behaviour of escaped farmed Atlantic salmon <i>Salmo salar</i> L. at the northern limit of its range, 39 adult salmon (mean ± SD fork length and weight: 85.5 ± 5.0 cm and 7.4 ± 1.4 kg, respectively) were implanted ... -
Effects of salmon lice on sea trout
(Research report; Forskningsrapport, 2014) -
Fangstrater, oppvandring og fordeling av laks i Altaelva
(Research report; Forskningsrapport, 2010-06)Bakgrunn og formål Gjennom internasjonale avtaler har Norge forpliktet seg til å forvalte den atlantiske laksen i henhold til føre-var tilnærmingen, slik at bestandene ikke reduseres til et nivå hvor rekrutteringen avtar i betydelig grad. For å forvalte laksestammer og vurdere om de har nådd sine gytebestandsmål er det blant annet behov for kunnskap om fangstrater og bestandsstørrelser, noe som ... -
Homing behaviour of Atlantic salmon (Salmo salar) during final phase of marine migration and river entry
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Little is known about Atlantic salmon behaviour during the last phase of the marine homing migration and subsequent river entry. In this study, 56 adult Atlantic salmon in the Alta Fjord in northern Norway were equipped with acoustic transmitters. Salmon generally followed the coastline, but their horizontal distribution was also affected by wind-induced spreading of river water across the fjord. ... -
Migratory behaviour and survival rates of wild northern Atlantic salmon (Salmo salar) post-smolts: effects of environmental factors
(Journal article; Tidsskriftartikkel; Peer reviewed, 2009-12-03)To study smolt behaviour and survival of a northern Atlantic salmon (Salmo salar) population during river descent, sea entry and fjord migration, 120 wild S. salar were tagged with acoustic tags and registered at four automatic listening station arrays in the mouth of the North Norwegian River Alta and throughout the Alta Fjord. An estimated 75% of the post-smolts survived from the river mouth, ... -
Migratory behaviour and survival rates of wild northern Atlantic salmon Salmo salar post-smolts: effects of environmental factors
(Conference object; Konferansebidrag, 2009-09-14) -
Redefining the oceanic distribution of Atlantic salmon
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-10)Determining the mechanisms driving range-wide reductions in Atlantic salmon marine survival is hindered by an insufcient understanding of their oceanic ecology and distribution. We attached 204 pop-up satellite archival tags to post-spawned salmon when they migrated to the ocean from seven European areas and maiden North American salmon captured at sea at West Greenland. Individuals migrated ... -
Sea trout adapt their migratory behaviour in response to high salmon lice concentrations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-21)Sea trout face growth–mortality trade-offs when entering the sea to feed. Salmon lice epizootics resulting from aquaculture have shifted these trade-offs, as salmon lice might both increase mortality and reduce growth of sea trout. We studied mortality and behavioural adaptations of wild sea trout in a large-scale experiment with acoustic telemetry in an aquaculture intensive area that was fallowed ... -
State-dependent migratory timing of postspawned Atlantic salmon (Salmo salar)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Atlantic salmon (Salmo salar) often survive spawning and migrate back to the sea to feed, either shortly after spawning in autumn or the following spring. We conducted a 4-year observational field study using telemetry to evaluate the determinants of migration timing in Atlantic salmon postspawners (kelts). We found that individuals with low energy reserves migrated early to the risky but productive ... -
Staying alive : the survival and importance of Atlantic salmon post-spawners
(Doctoral thesis; Doktorgradsavhandling, 2011-08-19)Summary Atlantic salmon (Salmo salar L.) repeat-spawners might play an important role in population persistence by increasing both total recruitment and long-term stability of a population. This is because repeat spawners return at larger sizes and with greater fecundity than first time spawners, and the large majority of repeat-spawners are females. Nevertheless, little knowledge exists of this ...
