Variability of demographic parameters and population dynamics of Atlantic salmon Salmo salar L. in a south-west French river
Abstract The abundance of the salmon population in the Nivelle River was assessed for 11 cohorts during all the stages of their life cycle, from eggs to spawners. A stochastic life history model was used to simulate the changes in numbers at each stage over several years and to evaluate the paramete...
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Online Access: | http://dx.doi.org/10.1016/s1054-3139(03)00003-1 http://academic.oup.com/icesjms/article-pdf/60/2/356/29118862/60-2-356.pdf |
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croxfordunivpr:10.1016/s1054-3139(03)00003-1 2023-12-31T10:04:50+01:00 Variability of demographic parameters and population dynamics of Atlantic salmon Salmo salar L. in a south-west French river Dumas, J. Prouzet, P. 2003 http://dx.doi.org/10.1016/s1054-3139(03)00003-1 http://academic.oup.com/icesjms/article-pdf/60/2/356/29118862/60-2-356.pdf en eng Oxford University Press (OUP) ICES Journal of Marine Science volume 60, issue 2, page 356-370 ISSN 1095-9289 1054-3139 Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography journal-article 2003 croxfordunivpr https://doi.org/10.1016/s1054-3139(03)00003-1 2023-12-06T08:47:41Z Abstract The abundance of the salmon population in the Nivelle River was assessed for 11 cohorts during all the stages of their life cycle, from eggs to spawners. A stochastic life history model was used to simulate the changes in numbers at each stage over several years and to evaluate the parameters of a Ricker-type Stock and Recruitment (S–R) relationship. Parameters necessary for managing the exploitation of the species were also estimated. The results indicated that an average deposition of 611 700 eggs (values varying in a proportion of 1 to 3, depending on the year) produced 4870 0+ parr in autumn (variation from 1 to 5.6); 71.8% of which belonged to the group of future 1-year old smolts. The age 1+ parr were eight times less numerous. Survival from egg to 0+ parr was on average 0.97%, but highly variable (varying from 1 to 15). It was density-dependent and followed Ricker S–R model with an optimum of 7800 parr for a survival rate of 3%. During their second year, the survival of 1+ parr reached 53.4% and varied little. The adult runs of complete cohorts amounted to 196 maiden salmon (range, 88 to 382) and previous spawners comprised only 0.9% of adults. Grilse (1 year in the sea) constituted the majority (88.7%). The overall survival rates from 0+ parr to adult returns (6.2% on average) varied three-fold. The majority was females among the grilse (56.2%) and 2-sea-year salmon (88.6%); all 3-sea-year adults were female. Eggs deposited per female averaged 4200, 8500 and 12 750 eggs in each age group, respectively. Simulations of population abundances at various life stages were in good agreement with the observed data. The S–R relationship revealed the low productivity and the vulnerability of this stock, mainly due to the low survival rate of the young during their first year of life. The maximum yield of 12.2% of recruits could be obtained from a deposition of 1 424 000 eggs, which is twice the present average level. Article in Journal/Newspaper Atlantic salmon Salmo salar Oxford University Press (via Crossref) ICES Journal of Marine Science 60 2 356 370 |
institution |
Open Polar |
collection |
Oxford University Press (via Crossref) |
op_collection_id |
croxfordunivpr |
language |
English |
topic |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography |
spellingShingle |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography Dumas, J. Prouzet, P. Variability of demographic parameters and population dynamics of Atlantic salmon Salmo salar L. in a south-west French river |
topic_facet |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography |
description |
Abstract The abundance of the salmon population in the Nivelle River was assessed for 11 cohorts during all the stages of their life cycle, from eggs to spawners. A stochastic life history model was used to simulate the changes in numbers at each stage over several years and to evaluate the parameters of a Ricker-type Stock and Recruitment (S–R) relationship. Parameters necessary for managing the exploitation of the species were also estimated. The results indicated that an average deposition of 611 700 eggs (values varying in a proportion of 1 to 3, depending on the year) produced 4870 0+ parr in autumn (variation from 1 to 5.6); 71.8% of which belonged to the group of future 1-year old smolts. The age 1+ parr were eight times less numerous. Survival from egg to 0+ parr was on average 0.97%, but highly variable (varying from 1 to 15). It was density-dependent and followed Ricker S–R model with an optimum of 7800 parr for a survival rate of 3%. During their second year, the survival of 1+ parr reached 53.4% and varied little. The adult runs of complete cohorts amounted to 196 maiden salmon (range, 88 to 382) and previous spawners comprised only 0.9% of adults. Grilse (1 year in the sea) constituted the majority (88.7%). The overall survival rates from 0+ parr to adult returns (6.2% on average) varied three-fold. The majority was females among the grilse (56.2%) and 2-sea-year salmon (88.6%); all 3-sea-year adults were female. Eggs deposited per female averaged 4200, 8500 and 12 750 eggs in each age group, respectively. Simulations of population abundances at various life stages were in good agreement with the observed data. The S–R relationship revealed the low productivity and the vulnerability of this stock, mainly due to the low survival rate of the young during their first year of life. The maximum yield of 12.2% of recruits could be obtained from a deposition of 1 424 000 eggs, which is twice the present average level. |
format |
Article in Journal/Newspaper |
author |
Dumas, J. Prouzet, P. |
author_facet |
Dumas, J. Prouzet, P. |
author_sort |
Dumas, J. |
title |
Variability of demographic parameters and population dynamics of Atlantic salmon Salmo salar L. in a south-west French river |
title_short |
Variability of demographic parameters and population dynamics of Atlantic salmon Salmo salar L. in a south-west French river |
title_full |
Variability of demographic parameters and population dynamics of Atlantic salmon Salmo salar L. in a south-west French river |
title_fullStr |
Variability of demographic parameters and population dynamics of Atlantic salmon Salmo salar L. in a south-west French river |
title_full_unstemmed |
Variability of demographic parameters and population dynamics of Atlantic salmon Salmo salar L. in a south-west French river |
title_sort |
variability of demographic parameters and population dynamics of atlantic salmon salmo salar l. in a south-west french river |
publisher |
Oxford University Press (OUP) |
publishDate |
2003 |
url |
http://dx.doi.org/10.1016/s1054-3139(03)00003-1 http://academic.oup.com/icesjms/article-pdf/60/2/356/29118862/60-2-356.pdf |
genre |
Atlantic salmon Salmo salar |
genre_facet |
Atlantic salmon Salmo salar |
op_source |
ICES Journal of Marine Science volume 60, issue 2, page 356-370 ISSN 1095-9289 1054-3139 |
op_doi |
https://doi.org/10.1016/s1054-3139(03)00003-1 |
container_title |
ICES Journal of Marine Science |
container_volume |
60 |
container_issue |
2 |
container_start_page |
356 |
op_container_end_page |
370 |
_version_ |
1786836273126703104 |