Restaureringens effekt på öringpopulationen
Until the 1970s, rivers in Sweden were used for timber floating. In order for the floating to be as efficient as possible, with a minimum of timber getting stuck, many rivers were cleared. Large rocks and boulders were removed from the main channel and tributaries, backwaters and shallow areas were...
| Autores principales: | , |
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| Formato: | First cycle, G2E |
| Lenguaje: | Inglés sueco |
| Publicado: |
2022
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| Materias: | |
| Acceso en línea: | https://stud.epsilon.slu.se/17465/ |
| _version_ | 1855572901716033536 |
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| author | Carlström, Ola Dagman, Sebastian |
| author_browse | Carlström, Ola Dagman, Sebastian |
| author_facet | Carlström, Ola Dagman, Sebastian |
| author_sort | Carlström, Ola |
| collection | Epsilon Archive for Student Projects |
| description | Until the 1970s, rivers in Sweden were used for timber floating. In order for the floating to be as efficient as possible, with a minimum of timber getting stuck, many rivers were cleared. Large rocks and boulders were removed from the main channel and tributaries, backwaters and shallow areas were secluded. This meant that the current increased in the main channel and became more homogeneous. Additional effects of the clearing were increased transport of sediment, increased bottom ice formation and poorer conditions for reproduction and survival for insects and fish. Restoration is a method used to restore the structure of watercourses. The goal is to achieve a heterogeneous structure in terms of e.g. depth, current conditions and
substrate. Through restoration, habitats and spawning grounds can be created for trout. The aim of this study is to examine the effects of restoration on the trout population. The trout stocks were inventoried with the help of electric fishing as the population can be estimated
and followed over time at the same location. The watercourses that have been studied are 6 tributaries to the Vindel river: Beukabäcken, Giertsbäcken, Nackbäcken, Olsbäcken, Ruskträskbäcken and Storkvarnbäcken. The results of the restoration show a significant difference in population density between the creeks and over time for 0+ trout. For >0+ trout, no significant difference in population density between the creeks or over time is found. How the trout population develops after a restoration highly depends on what the population looked like before the restoration. The conclusion is that the restoration has a positive effect on parts of the trout population, but it takes time before the fish establish themselves. |
| format | First cycle, G2E |
| id | RepoSLU17465 |
| institution | Swedish University of Agricultural Sciences |
| language | Inglés swe |
| publishDate | 2022 |
| publishDateSort | 2022 |
| record_format | eprints |
| spelling | RepoSLU174652022-01-15T02:01:34Z https://stud.epsilon.slu.se/17465/ Restaureringens effekt på öringpopulationen Carlström, Ola Dagman, Sebastian Aquatic ecology Until the 1970s, rivers in Sweden were used for timber floating. In order for the floating to be as efficient as possible, with a minimum of timber getting stuck, many rivers were cleared. Large rocks and boulders were removed from the main channel and tributaries, backwaters and shallow areas were secluded. This meant that the current increased in the main channel and became more homogeneous. Additional effects of the clearing were increased transport of sediment, increased bottom ice formation and poorer conditions for reproduction and survival for insects and fish. Restoration is a method used to restore the structure of watercourses. The goal is to achieve a heterogeneous structure in terms of e.g. depth, current conditions and substrate. Through restoration, habitats and spawning grounds can be created for trout. The aim of this study is to examine the effects of restoration on the trout population. The trout stocks were inventoried with the help of electric fishing as the population can be estimated and followed over time at the same location. The watercourses that have been studied are 6 tributaries to the Vindel river: Beukabäcken, Giertsbäcken, Nackbäcken, Olsbäcken, Ruskträskbäcken and Storkvarnbäcken. The results of the restoration show a significant difference in population density between the creeks and over time for 0+ trout. For >0+ trout, no significant difference in population density between the creeks or over time is found. How the trout population develops after a restoration highly depends on what the population looked like before the restoration. The conclusion is that the restoration has a positive effect on parts of the trout population, but it takes time before the fish establish themselves. vara så effektiv som möjligt, med minimalt med timmer som fastande och dröjde sig kvar, flottledsrensades många älvar. Stora stenar och block avlägsnades från huvudfåran och biflöden, bakvatten och grundområden stängdes av. Detta medförde att strömmen tilltog i huvudfåran och blev mer homogen. Ytterligare effekter av flottledsrensingen var en ökad transport av sediment, ökad bottenisbildning och sämre förutsättningar till reproduktion och överlevnad för insekter och fisk. Restaurering av vattendragen är en metod som används för att återställa vattendragens struktur. Målet är att uppnå en heterogen struktur vad avser bl. a. djup, strömförhållanden och substrat. Genom restaurering kan habitat och lekplatser skapas för exempelvis öring. Syftet med studien är att undersöka hur öringpopulationerna påverkas av restaureringar. Öringbestånden inventeras med hjälp av elfiske då populationen kan skattas och följas över tid vid en och samma lokal. De vattendrag som har studerats är 6 biflöden till Vindelälven: Beukabäcken, Giertsbäcken, Nackbäcken, Olsbäcken, Ruskträskbäcken och Storkvarnbäcken. Resultatet av restaureringen visar en signifikant skillnad i populationstäthet mellan bäckarna och över tid för 0+ öringar. För >0+ öringar påvisas ingen signifikant skillnad i populationstäthet mellan bäckarna och över tid. Hur öringpopulationen utvecklas efter en restaureringsåtgärd beror till stor del på hur beståndet såg ut innan restaureringen. Slutsatsen är att restaureringen har positiv effekt på delar av öringpopulationen men att det är en åtgärd som tar tid innan fisken etablerar sig. 2022-01-13 First cycle, G2E NonPeerReviewed application/pdf en https://stud.epsilon.slu.se/17465/1/Carlstrom_Dagman_220113.pdf Carlström, Ola and Dagman, Sebastian, 2022. Restaureringens effekt på öringpopulationen. First cycle, G2E. Umeå: (S) > Dept. of Forest Ecology and Management <https://stud.epsilon.slu.se/view/divisions/OID-241.html> urn:nbn:se:slu:epsilon-s-17465 swe |
| spellingShingle | Aquatic ecology Carlström, Ola Dagman, Sebastian Restaureringens effekt på öringpopulationen |
| title | Restaureringens effekt på öringpopulationen |
| title_full | Restaureringens effekt på öringpopulationen |
| title_fullStr | Restaureringens effekt på öringpopulationen |
| title_full_unstemmed | Restaureringens effekt på öringpopulationen |
| title_short | Restaureringens effekt på öringpopulationen |
| title_sort | restaureringens effekt på öringpopulationen |
| topic | Aquatic ecology |
| url | https://stud.epsilon.slu.se/17465/ https://stud.epsilon.slu.se/17465/ |