Downstream migration of salmon smolts in regulated rivers:factors affecting survival and behaviour
Abstract Atlantic salmon is one of the most widely known migratory fish species whose populations have declined because of hydropower installations. Attempts have been made to preserve salmon stocks in regulated rivers by building fishways for adult fish migrating upstream, but downstream migration...
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2018
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Online Access: | http://urn.fi/urn:isbn:9789526217840 |
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ftunivoulu:oai:oulu.fi:isbn978-952-62-1784-0 2023-07-30T04:02:27+02:00 Downstream migration of salmon smolts in regulated rivers:factors affecting survival and behaviour Huusko, R. (Riina) Erkinaro, J. (Jaakko) Muotka, T. (Timo) 2018-01-16 application/pdf http://urn.fi/urn:isbn:9789526217840 eng eng Oulun yliopisto info:eu-repo/semantics/altIdentifier/pissn/0355-3191 info:eu-repo/semantics/altIdentifier/eissn/1796-220X info:eu-repo/semantics/openAccess © University of Oulu, 2018 fish tags hatchery-rearing hydropower migration speed telemetry kalamerkit laitoskasvatus telemetria vaellusnopeus vesivoima info:eu-repo/semantics/doctoralThesis info:eu-repo/semantics/publishedVersion 2018 ftunivoulu 2023-07-08T19:53:50Z Abstract Atlantic salmon is one of the most widely known migratory fish species whose populations have declined because of hydropower installations. Attempts have been made to preserve salmon stocks in regulated rivers by building fishways for adult fish migrating upstream, but downstream migration of salmon smolts has been almost totally ignored. Instead, captive breeding programmes and extensive stocking of hatchery-reared salmon smolts have been initiated to compensate for highly reduced natural production and to maintain salmon yields. In recent decades, demands to reduce the environmental effects of hydropower production, together with public awareness of decreasing recapture rate and yield of stocked salmon, have increased calls for rebuilding wild salmon stocks in rivers modified for hydropower production. As a consequence, survival of salmon smolts during downstream migration and the effects of hatchery rearing and stocking methods are now research topics of high importance. This thesis examined the need for modifications to the current standard hatchery rearing and release methods, determined the effects of commonly used tagging methods and investigated the impacts of river regulation on the survival and behaviour of downstream migrating smolts by applying telemetry techniques. Modifications made to the standard rearing processes noticeably affected the physiology, behaviour and survival of salmon smolts. In addition, the timing of release was shown to be a key factor for the survival of released smolts. Therefore, comprehensive rearing of smolts, and improving current release methods, especially to match the timing of release to the migration window of wild smolts, are high priorities. Observations in semi-natural environments indicated that commonly used tagging methods had only slight effects on the survival of smolts, so they can be freely used to examine smolt performance. However, more information on rearing and stocking processes and tagging methods is still needed to fully verify the present ... Doctoral or Postdoctoral Thesis Atlantic salmon Jultika - University of Oulu repository |
institution |
Open Polar |
collection |
Jultika - University of Oulu repository |
op_collection_id |
ftunivoulu |
language |
English |
topic |
fish tags hatchery-rearing hydropower migration speed telemetry kalamerkit laitoskasvatus telemetria vaellusnopeus vesivoima |
spellingShingle |
fish tags hatchery-rearing hydropower migration speed telemetry kalamerkit laitoskasvatus telemetria vaellusnopeus vesivoima Huusko, R. (Riina) Downstream migration of salmon smolts in regulated rivers:factors affecting survival and behaviour |
topic_facet |
fish tags hatchery-rearing hydropower migration speed telemetry kalamerkit laitoskasvatus telemetria vaellusnopeus vesivoima |
description |
Abstract Atlantic salmon is one of the most widely known migratory fish species whose populations have declined because of hydropower installations. Attempts have been made to preserve salmon stocks in regulated rivers by building fishways for adult fish migrating upstream, but downstream migration of salmon smolts has been almost totally ignored. Instead, captive breeding programmes and extensive stocking of hatchery-reared salmon smolts have been initiated to compensate for highly reduced natural production and to maintain salmon yields. In recent decades, demands to reduce the environmental effects of hydropower production, together with public awareness of decreasing recapture rate and yield of stocked salmon, have increased calls for rebuilding wild salmon stocks in rivers modified for hydropower production. As a consequence, survival of salmon smolts during downstream migration and the effects of hatchery rearing and stocking methods are now research topics of high importance. This thesis examined the need for modifications to the current standard hatchery rearing and release methods, determined the effects of commonly used tagging methods and investigated the impacts of river regulation on the survival and behaviour of downstream migrating smolts by applying telemetry techniques. Modifications made to the standard rearing processes noticeably affected the physiology, behaviour and survival of salmon smolts. In addition, the timing of release was shown to be a key factor for the survival of released smolts. Therefore, comprehensive rearing of smolts, and improving current release methods, especially to match the timing of release to the migration window of wild smolts, are high priorities. Observations in semi-natural environments indicated that commonly used tagging methods had only slight effects on the survival of smolts, so they can be freely used to examine smolt performance. However, more information on rearing and stocking processes and tagging methods is still needed to fully verify the present ... |
author2 |
Erkinaro, J. (Jaakko) Muotka, T. (Timo) |
format |
Doctoral or Postdoctoral Thesis |
author |
Huusko, R. (Riina) |
author_facet |
Huusko, R. (Riina) |
author_sort |
Huusko, R. (Riina) |
title |
Downstream migration of salmon smolts in regulated rivers:factors affecting survival and behaviour |
title_short |
Downstream migration of salmon smolts in regulated rivers:factors affecting survival and behaviour |
title_full |
Downstream migration of salmon smolts in regulated rivers:factors affecting survival and behaviour |
title_fullStr |
Downstream migration of salmon smolts in regulated rivers:factors affecting survival and behaviour |
title_full_unstemmed |
Downstream migration of salmon smolts in regulated rivers:factors affecting survival and behaviour |
title_sort |
downstream migration of salmon smolts in regulated rivers:factors affecting survival and behaviour |
publisher |
Oulun yliopisto |
publishDate |
2018 |
url |
http://urn.fi/urn:isbn:9789526217840 |
genre |
Atlantic salmon |
genre_facet |
Atlantic salmon |
op_relation |
info:eu-repo/semantics/altIdentifier/pissn/0355-3191 info:eu-repo/semantics/altIdentifier/eissn/1796-220X |
op_rights |
info:eu-repo/semantics/openAccess © University of Oulu, 2018 |
_version_ |
1772813251895099392 |