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Atlantic salmon (Salmo salar) smolt production: the relative importance of survival and body growth

Canadian Journal of Fisheries and Aquatic Sciences

By:
, , ,
DOI: 10.1139/F09-005

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Abstract

The complex life history of Atlantic salmon (Salmo salar) coupled with interacting abiotic and biotic factors leads to extreme demographic variability across the species' range. Our goal was to evaluate the relative importance of survival and body growth in determining smolt production across space and time. We used passive integrated transponder tags and capture-mark-recapture analyses to estimate survival, emigration, and growth for six cohorts of presmolt Atlantic salmon in two streams (three cohorts per stream) in New England, USA. We observed remarkable among-cohort consistency in mean monthly survival during a 17-month period from age-0+ autumn to age-2+ spring yet high variability in monthly survival over shorter time intervals (seasons). Despite this latter variability, survival did not translate into amongcohort differences in proportions of age-2+ versus age-3+ smolts. Alternatively, the high variability across seasons and cohorts in mean individual growth rate did lead to differences in within-cohort proportions of age-2+ versus age-3+ smolts (regardless of stream). We conclude that in our two small study streams, variability in growth and size impacted smolt age and, ultimately, smolt production. Density-dependent effects on growth at the scale of the entire study site represent a possible mechanism underlying our observations.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Atlantic salmon (Salmo salar) smolt production: the relative importance of survival and body growth
Series title:
Canadian Journal of Fisheries and Aquatic Sciences
DOI:
10.1139/F09-005
Volume
66
Issue:
3
Year Published:
2009
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
471
Last page:
483
Number of Pages:
13