From the river to the open sea : a critical life phase of young Atlantic salmon migrating from the Simojoki river
Long-term monitoring data collected from wild smolts of Atlantic salmon (Salmo salar) in the Simojoki river, northern Finland, were used in studying the relationships between the smolt size and age, smolt and postsmolt migration, environmental conditions and postsmolt survival. The onset of the smol...
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Language: | English |
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Helsingin yliopisto
2010
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Online Access: | http://hdl.handle.net/10138/22014 |
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ftunivhelsihelda:oai:helda.helsinki.fi:10138/22014 2023-08-20T04:05:19+02:00 From the river to the open sea : a critical life phase of young Atlantic salmon migrating from the Simojoki river Jutila, Eero Hirvonen, Heikki Finnish Game and Fisheries Research Institute University of Helsinki, Faculty of Biosciences, Department of Biological and Environmental Sciences Helsingin yliopisto, biotieteellinen tiedekunta, bio- ja ympäristötieteiden laitos Helsingfors universitet, biovetenskapliga fakulteten, institutionen för bio- och miljövetenskaper Salminen, Matti Erkinaro, Jaakko 2010-11-25T13:16:06Z application/pdf http://hdl.handle.net/10138/22014 eng eng Helsingin yliopisto Helsingfors universitet University of Helsinki URN:ISBN:978-951-776-676-2 Tampere: 2008 http://hdl.handle.net/10138/22014 URN:ISBN:978-951-776-628-9 Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty. This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited. kalataloustiede Text Doctoral dissertation (article-based) Artikkeliväitöskirja Artikelavhandling doctoralThesis 2010 ftunivhelsihelda 2023-07-28T06:32:39Z Long-term monitoring data collected from wild smolts of Atlantic salmon (Salmo salar) in the Simojoki river, northern Finland, were used in studying the relationships between the smolt size and age, smolt and postsmolt migration, environmental conditions and postsmolt survival. The onset of the smolt run was significantly dependent on the rising water temperature and decreasing discharge of the river in the spring. The mean length of smolts migrating early in the season was commonly higher and the mean age always older than among smolts migrating later. Many of the smolts migrating early in the season and almost all smolts migrating later had started their new growth in spring in the river before their sea entry. Among postsmolts, the time required for emigration from the estuary was dependent on the sea surface temperature (SST) off the river, being significantly shorter in years with warm than cold sea temperatures. After leaving the estuary, the postsmolts migrated southwards along the eastern coast of the northern Gulf of Bothnia, the geographical distribution of the tag recoveries coinciding with the warm thermal zone in spring in the coastal area. After arriving in the southern Gulf of Bothnia in late summer the postsmolts mostly migrated near the western coast, reaching the Baltic Main Basin in late autumn. Until the early 1990s there was only a weak positive association between smolt length and postsmolt survival. However, following a subsequent decrease in the mean smolt size, a significant positive dependence was observed between smolt size and the reported recapture rate of tagged salmon. The differences in recapture rates between smolts tagged during the first and second half of the annual migration season were insignificant, indicating that the seasonal variation in smolt size and age seem to be too small to affect survival. Among the climatic factors examined, the summer SST in the Gulf of Bothnia was most clearly related to the survival of the wild postsmolts. Postsmolt survival appeared to be ... Doctoral or Postdoctoral Thesis Atlantic salmon Northern Finland Salmo salar Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto Simojoki ENVELOPE(25.050,25.050,65.617,65.617) |
institution |
Open Polar |
collection |
Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto |
op_collection_id |
ftunivhelsihelda |
language |
English |
topic |
kalataloustiede |
spellingShingle |
kalataloustiede Jutila, Eero From the river to the open sea : a critical life phase of young Atlantic salmon migrating from the Simojoki river |
topic_facet |
kalataloustiede |
description |
Long-term monitoring data collected from wild smolts of Atlantic salmon (Salmo salar) in the Simojoki river, northern Finland, were used in studying the relationships between the smolt size and age, smolt and postsmolt migration, environmental conditions and postsmolt survival. The onset of the smolt run was significantly dependent on the rising water temperature and decreasing discharge of the river in the spring. The mean length of smolts migrating early in the season was commonly higher and the mean age always older than among smolts migrating later. Many of the smolts migrating early in the season and almost all smolts migrating later had started their new growth in spring in the river before their sea entry. Among postsmolts, the time required for emigration from the estuary was dependent on the sea surface temperature (SST) off the river, being significantly shorter in years with warm than cold sea temperatures. After leaving the estuary, the postsmolts migrated southwards along the eastern coast of the northern Gulf of Bothnia, the geographical distribution of the tag recoveries coinciding with the warm thermal zone in spring in the coastal area. After arriving in the southern Gulf of Bothnia in late summer the postsmolts mostly migrated near the western coast, reaching the Baltic Main Basin in late autumn. Until the early 1990s there was only a weak positive association between smolt length and postsmolt survival. However, following a subsequent decrease in the mean smolt size, a significant positive dependence was observed between smolt size and the reported recapture rate of tagged salmon. The differences in recapture rates between smolts tagged during the first and second half of the annual migration season were insignificant, indicating that the seasonal variation in smolt size and age seem to be too small to affect survival. Among the climatic factors examined, the summer SST in the Gulf of Bothnia was most clearly related to the survival of the wild postsmolts. Postsmolt survival appeared to be ... |
author2 |
Hirvonen, Heikki Finnish Game and Fisheries Research Institute University of Helsinki, Faculty of Biosciences, Department of Biological and Environmental Sciences Helsingin yliopisto, biotieteellinen tiedekunta, bio- ja ympäristötieteiden laitos Helsingfors universitet, biovetenskapliga fakulteten, institutionen för bio- och miljövetenskaper Salminen, Matti Erkinaro, Jaakko |
format |
Doctoral or Postdoctoral Thesis |
author |
Jutila, Eero |
author_facet |
Jutila, Eero |
author_sort |
Jutila, Eero |
title |
From the river to the open sea : a critical life phase of young Atlantic salmon migrating from the Simojoki river |
title_short |
From the river to the open sea : a critical life phase of young Atlantic salmon migrating from the Simojoki river |
title_full |
From the river to the open sea : a critical life phase of young Atlantic salmon migrating from the Simojoki river |
title_fullStr |
From the river to the open sea : a critical life phase of young Atlantic salmon migrating from the Simojoki river |
title_full_unstemmed |
From the river to the open sea : a critical life phase of young Atlantic salmon migrating from the Simojoki river |
title_sort |
from the river to the open sea : a critical life phase of young atlantic salmon migrating from the simojoki river |
publisher |
Helsingin yliopisto |
publishDate |
2010 |
url |
http://hdl.handle.net/10138/22014 |
long_lat |
ENVELOPE(25.050,25.050,65.617,65.617) |
geographic |
Simojoki |
geographic_facet |
Simojoki |
genre |
Atlantic salmon Northern Finland Salmo salar |
genre_facet |
Atlantic salmon Northern Finland Salmo salar |
op_relation |
URN:ISBN:978-951-776-676-2 Tampere: 2008 http://hdl.handle.net/10138/22014 URN:ISBN:978-951-776-628-9 |
op_rights |
Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty. This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited. |
_version_ |
1774715814251855872 |