Fysiska strukturer i Umeälvens gamla älvfåra och dess inverkan på laxsmoltens utvandringsframgång
The survival of hatchery reared smolts is generally low after release. To get a better understanding of what variables affecting migration success, Atlantic salmon smolts were studied during their out-migration in the old river channel in the lower part of river Umeälven. The area consists of shifti...
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| Formato: | H2 |
| Lenguaje: | sueco Inglés |
| Publicado: |
SLU/Dept. of Wildlife, Fish and Environmental Studies
2014
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| Materias: |
| _version_ | 1855571162998767616 |
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| author | Tegenfeldt, Viktoria |
| author_browse | Tegenfeldt, Viktoria |
| author_facet | Tegenfeldt, Viktoria |
| author_sort | Tegenfeldt, Viktoria |
| collection | Epsilon Archive for Student Projects |
| description | The survival of hatchery reared smolts is generally low after release. To get a better understanding of what variables affecting migration success, Atlantic salmon smolts were studied during their out-migration in the old river channel in the lower part of river Umeälven. The area consists of shifting habitat and complex structures which causes difficulties for smolt on their migration out to sea. The aim of this study was to try to determine the effects of feed restriction, fin conditions and different physical barriers in the river, on the migratory behavior of Atlantic salmon smolts in the river Umeälven.
The river was divided into six different sections using acoustic receivers strategically deployed along the river. Two-year old hatchery-reared smolts (n=150), in three different weight classes, were tagged with acoustic transmitters. The fish were released in late May 2013 and monitored while migrating downstream. A majority of the smolts migrated to the sea within two days after release.
The smolts showed different migration speeds for different sections of the river. In sections containing large substrate size, steep incline and large proportion of rapids the smolts showed a significantly slower migration speed. The migration speed was similar for all weight classes and only a poor condition on the pectoral fin had a significant negative effect on migration speed. Compared to previous studies in the river, the survival and migration speed was high. At the time of release, the water flow was twice as high as in previous studies, which probably explained the higher migratory success. |
| format | H2 |
| id | RepoSLU7314 |
| institution | Swedish University of Agricultural Sciences |
| language | swe Inglés |
| publishDate | 2014 |
| publishDateSort | 2014 |
| publisher | SLU/Dept. of Wildlife, Fish and Environmental Studies |
| publisherStr | SLU/Dept. of Wildlife, Fish and Environmental Studies |
| record_format | eprints |
| spelling | RepoSLU73142014-09-17T15:27:45Z Fysiska strukturer i Umeälvens gamla älvfåra och dess inverkan på laxsmoltens utvandringsframgång The effect of physical structures within the old river bed of river Umeälven on smolt migration Tegenfeldt, Viktoria smolt vandring fysiska strukturer Umeälven akustiska sändare The survival of hatchery reared smolts is generally low after release. To get a better understanding of what variables affecting migration success, Atlantic salmon smolts were studied during their out-migration in the old river channel in the lower part of river Umeälven. The area consists of shifting habitat and complex structures which causes difficulties for smolt on their migration out to sea. The aim of this study was to try to determine the effects of feed restriction, fin conditions and different physical barriers in the river, on the migratory behavior of Atlantic salmon smolts in the river Umeälven. The river was divided into six different sections using acoustic receivers strategically deployed along the river. Two-year old hatchery-reared smolts (n=150), in three different weight classes, were tagged with acoustic transmitters. The fish were released in late May 2013 and monitored while migrating downstream. A majority of the smolts migrated to the sea within two days after release. The smolts showed different migration speeds for different sections of the river. In sections containing large substrate size, steep incline and large proportion of rapids the smolts showed a significantly slower migration speed. The migration speed was similar for all weight classes and only a poor condition on the pectoral fin had a significant negative effect on migration speed. Compared to previous studies in the river, the survival and migration speed was high. At the time of release, the water flow was twice as high as in previous studies, which probably explained the higher migratory success. Överlevnaden hos odlad smolt är generellt låg efter utsättning. För att få en bättre förståelse för vilka variabler som påverkar laxsmoltens migrationsframgång, studerades dess utvandring genom den gamla älvfåran i de nedre delarna av Umeälven. Området består av skiftande habitat och komplexa strukturer, vilket försvårar fiskens vandring ut mot havet. Syftet med denna studie var att försöka förstå vilka effekter en reducerad födotillgång, fiskens fenstatus och olika fysiska barriärer har på migrationsbeteendet hos laxsmolten i Umeälven. Älven delades in i sex olika delarsträckor med hjälp av akustiska mottagare, strategiskt utplacerade i älven. Tvåårig odlad laxsmolt (n=150), i tre olika storleksklasser märktes med akustiska sändare. Smolten släpptes sent i maj 2013 och följdes under sin utvandring. Majoriteten av smolten vandrade ut till havet inom två dagar efter utsättning. Hastigheten hos smolten skiljde sig åt mellan olika delsträckor och på sträckor innehållande stora substrat, hög andel fors och fallhöjd hade smolten en signifikant lägre medelhastighet än övriga. Migrationshastigheten var lika för samtliga viktklasser och endast en dålig status på bröstfenan hade en signifikant negativ inverkan på fiskens medelhastighet. Både överlevnad och medelhastigheten var hög jämfört med tidigare års studier. Vid tidpunkten när fiskens släpptes var vattenflödet dubbelt så högt jämfört med tidigare år, något som troligtvis förklarade den högre migrationsframgången. SLU/Dept. of Wildlife, Fish and Environmental Studies 2014 H2 swe eng https://stud.epsilon.slu.se/7314/ |
| spellingShingle | smolt vandring fysiska strukturer Umeälven akustiska sändare Tegenfeldt, Viktoria Fysiska strukturer i Umeälvens gamla älvfåra och dess inverkan på laxsmoltens utvandringsframgång |
| title | Fysiska strukturer i Umeälvens gamla älvfåra och dess inverkan på laxsmoltens utvandringsframgång |
| title_full | Fysiska strukturer i Umeälvens gamla älvfåra och dess inverkan på laxsmoltens utvandringsframgång |
| title_fullStr | Fysiska strukturer i Umeälvens gamla älvfåra och dess inverkan på laxsmoltens utvandringsframgång |
| title_full_unstemmed | Fysiska strukturer i Umeälvens gamla älvfåra och dess inverkan på laxsmoltens utvandringsframgång |
| title_short | Fysiska strukturer i Umeälvens gamla älvfåra och dess inverkan på laxsmoltens utvandringsframgång |
| title_sort | fysiska strukturer i umeälvens gamla älvfåra och dess inverkan på laxsmoltens utvandringsframgång |
| topic | smolt vandring fysiska strukturer Umeälven akustiska sändare |