Conservation of Atlantic salmon by supplementary stocking of juvenile fish
Wild salmon stocks in the northern Baltic rivers became endangered in the second half of the 20th century, mainly due to recruitment overfishing. As a result, supplementary stocking was widely practised, and supplementation of the Tornionjoki salmon stock took place over a 25 year period until 2002....
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Helsingin yliopisto
2010
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ftunivhelsihelda:oai:helda.helsinki.fi:10138/22041 2023-08-20T04:05:21+02:00 Conservation of Atlantic salmon by supplementary stocking of juvenile fish Poikasistutukset Atlantin lohen suojelukeinona Romakkaniemi, Atso Fleming, Ian University of Helsinki, Faculty of Biosciences, Department of Biological and Environmental Sciences, akvaattiset tieteet Riista- ja kalatalouden tutkimuslaitos Helsingin yliopisto, biotieteellinen tiedekunta, bio- ja ympäristötieteiden laitos Helsingfors universitet, biovetenskapliga fakulteten, institutionen för bio- och miljövetenskaper Erkinaro, Jaakko Kuikka, Sakari 2010-11-25T13:16:46Z application/pdf http://hdl.handle.net/10138/22041 eng eng Helsingin yliopisto Helsingfors universitet University of Helsinki URN:ISBN:978-952-92-4185-9 Helsinki, Yliopistopaino: Atso Romakkaniemi, 2008 http://hdl.handle.net/10138/22041 URN:ISBN:978-952-10-4780-0 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. Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. akvaattiset tieteet kalataloustiede Text Doctoral dissertation (article-based) Artikkeliväitöskirja Artikelavhandling doctoralThesis 2010 ftunivhelsihelda 2023-07-28T06:24:42Z Wild salmon stocks in the northern Baltic rivers became endangered in the second half of the 20th century, mainly due to recruitment overfishing. As a result, supplementary stocking was widely practised, and supplementation of the Tornionjoki salmon stock took place over a 25 year period until 2002. The stock has been closely monitored by electrofishing, smolt trapping, mark-recapture studies, catch samples and catch surveys. Background information on hatchery-reared stocked juveniles was also collected for this study. Bayesian statistics was applied to the data as this method offers the possibility of bringing prior information into the analysis and an advanced ability for incorporating uncertainty, and also provides probabilities for a multitude of hypotheses. Substantial divergences between reared and wild Tornionjoki salmon were identified in both demographic and phenological characteristics. The divergences tended to be larger the longer the duration spent in hatchery and the more favourable the hatchery conditions were for fast growth. Differences in environment likely induced most of the divergences, but selection of brood fish might have resulted in genotypic divergence in maturation age of reared salmon. Survival of stocked 1-year old juveniles to smolt varied from about 10% to about 25%. Stocking on the lower reach of the river seemed to decrease survival, and the negative effect of stocking volume on survival raises the concern of possible similar effects on the extant wild population. Post-smolt survival of wild Tornionjoki smolts was on average two times higher than that of smolts stocked as parr and 2.5 times higher than that of stocked smolts. Smolts of different groups showed synchronous variation and similar long-term survival trends. Both groups of reared salmon were more vulnerable to offshore driftnet and coastal trapnet fishing than wild salmon. Average survival from smolt to spawners of wild salmon was 2.8 times higher than that of salmon stocked as parr and 3.3 times higher than that of ... Doctoral or Postdoctoral Thesis Atlantic salmon Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto Tornionjoki ENVELOPE(24.153,24.153,65.813,65.813) |
institution |
Open Polar |
collection |
Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto |
op_collection_id |
ftunivhelsihelda |
language |
English |
topic |
akvaattiset tieteet kalataloustiede |
spellingShingle |
akvaattiset tieteet kalataloustiede Romakkaniemi, Atso Conservation of Atlantic salmon by supplementary stocking of juvenile fish |
topic_facet |
akvaattiset tieteet kalataloustiede |
description |
Wild salmon stocks in the northern Baltic rivers became endangered in the second half of the 20th century, mainly due to recruitment overfishing. As a result, supplementary stocking was widely practised, and supplementation of the Tornionjoki salmon stock took place over a 25 year period until 2002. The stock has been closely monitored by electrofishing, smolt trapping, mark-recapture studies, catch samples and catch surveys. Background information on hatchery-reared stocked juveniles was also collected for this study. Bayesian statistics was applied to the data as this method offers the possibility of bringing prior information into the analysis and an advanced ability for incorporating uncertainty, and also provides probabilities for a multitude of hypotheses. Substantial divergences between reared and wild Tornionjoki salmon were identified in both demographic and phenological characteristics. The divergences tended to be larger the longer the duration spent in hatchery and the more favourable the hatchery conditions were for fast growth. Differences in environment likely induced most of the divergences, but selection of brood fish might have resulted in genotypic divergence in maturation age of reared salmon. Survival of stocked 1-year old juveniles to smolt varied from about 10% to about 25%. Stocking on the lower reach of the river seemed to decrease survival, and the negative effect of stocking volume on survival raises the concern of possible similar effects on the extant wild population. Post-smolt survival of wild Tornionjoki smolts was on average two times higher than that of smolts stocked as parr and 2.5 times higher than that of stocked smolts. Smolts of different groups showed synchronous variation and similar long-term survival trends. Both groups of reared salmon were more vulnerable to offshore driftnet and coastal trapnet fishing than wild salmon. Average survival from smolt to spawners of wild salmon was 2.8 times higher than that of salmon stocked as parr and 3.3 times higher than that of ... |
author2 |
Fleming, Ian University of Helsinki, Faculty of Biosciences, Department of Biological and Environmental Sciences, akvaattiset tieteet Riista- ja kalatalouden tutkimuslaitos Helsingin yliopisto, biotieteellinen tiedekunta, bio- ja ympäristötieteiden laitos Helsingfors universitet, biovetenskapliga fakulteten, institutionen för bio- och miljövetenskaper Erkinaro, Jaakko Kuikka, Sakari |
format |
Doctoral or Postdoctoral Thesis |
author |
Romakkaniemi, Atso |
author_facet |
Romakkaniemi, Atso |
author_sort |
Romakkaniemi, Atso |
title |
Conservation of Atlantic salmon by supplementary stocking of juvenile fish |
title_short |
Conservation of Atlantic salmon by supplementary stocking of juvenile fish |
title_full |
Conservation of Atlantic salmon by supplementary stocking of juvenile fish |
title_fullStr |
Conservation of Atlantic salmon by supplementary stocking of juvenile fish |
title_full_unstemmed |
Conservation of Atlantic salmon by supplementary stocking of juvenile fish |
title_sort |
conservation of atlantic salmon by supplementary stocking of juvenile fish |
publisher |
Helsingin yliopisto |
publishDate |
2010 |
url |
http://hdl.handle.net/10138/22041 |
long_lat |
ENVELOPE(24.153,24.153,65.813,65.813) |
geographic |
Tornionjoki |
geographic_facet |
Tornionjoki |
genre |
Atlantic salmon |
genre_facet |
Atlantic salmon |
op_relation |
URN:ISBN:978-952-92-4185-9 Helsinki, Yliopistopaino: Atso Romakkaniemi, 2008 http://hdl.handle.net/10138/22041 URN:ISBN:978-952-10-4780-0 |
op_rights |
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. Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. |
_version_ |
1774715855583576064 |