Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts

Variability in animal migratory behavior is expected to influence fitness, but few empirical examples demonstrating this relationship exist. The initial marine phase in the migration of juvenile salmon smolts has been identified as a potentially critical life history stage to overall population prod...

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Autores principales: Furey, Nathan B., Vincent, Stephen P., Hinch, Scott G., Welch, David W.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4599731/
https://www.ncbi.nlm.nih.gov/pubmed/26451837
http://dx.doi.org/10.1371/journal.pone.0139269
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author Furey, Nathan B.
Vincent, Stephen P.
Hinch, Scott G.
Welch, David W.
author_facet Furey, Nathan B.
Vincent, Stephen P.
Hinch, Scott G.
Welch, David W.
author_sort Furey, Nathan B.
collection PubMed
description Variability in animal migratory behavior is expected to influence fitness, but few empirical examples demonstrating this relationship exist. The initial marine phase in the migration of juvenile salmon smolts has been identified as a potentially critical life history stage to overall population productivity, yet how fine-scale migration routes may influence survival are unknown. Large-scale acoustic telemetry studies have estimated survival rates of outmigrant Pacific salmon smolts through the Strait of Georgia (SOG) along the British Columbian coastline to the Pacific Ocean, but these data have not been used to identify and characterize fine-scale movements. Data collected on over 850 sockeye salmon (Oncorhynchus nerka) and steelhead (Oncorhynchus mykiss) smolts detected at an array in the Strait of Georgia in 2004–2008 and 2010–2013 were analyzed to characterize migration routes and link movements to subsequent survival at an array 250 km further along the marine migration pathway. Both species exhibited disproportionate use of the most eastern route in the Strait of Georgia (Malaspina Strait). While many smolts moved across the northern Strait of Georgia acoustic array with no indication of long-term milling or large-scale east-to-west movements, large proportions (20–40% of sockeye and 30–50% of steelhead) exhibited a different behavior, apparently moving in a westward or counterclockwise pattern. Variability in migratory behavior for both species was linked to subsequent survival through the Strait of Georgia. Survival for both species was influenced by initial east-to-west location, and sockeye were further influenced by migration timing and duration of time spent near the northern Strait of Georgia array. Westward movements result in a net transport of smolts from Malaspina Strait to the Strait of Georgia, particularly for steelhead. Counterclockwise movements may be due to the currents in this area during the time of outmigration, and the higher proportion of steelhead smolts exhibiting this counterclockwise behavior may reflect a greater exposure to wind-altered currents for the more surface-oriented steelhead. Our results provide an empirical example of how movements can affect migration survival, for which examples remain rare in movement ecology, confirming that variability in movements themselves are an important part of the migratory process.
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spelling pubmed-45997312015-10-20 Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts Furey, Nathan B. Vincent, Stephen P. Hinch, Scott G. Welch, David W. PLoS One Research Article Variability in animal migratory behavior is expected to influence fitness, but few empirical examples demonstrating this relationship exist. The initial marine phase in the migration of juvenile salmon smolts has been identified as a potentially critical life history stage to overall population productivity, yet how fine-scale migration routes may influence survival are unknown. Large-scale acoustic telemetry studies have estimated survival rates of outmigrant Pacific salmon smolts through the Strait of Georgia (SOG) along the British Columbian coastline to the Pacific Ocean, but these data have not been used to identify and characterize fine-scale movements. Data collected on over 850 sockeye salmon (Oncorhynchus nerka) and steelhead (Oncorhynchus mykiss) smolts detected at an array in the Strait of Georgia in 2004–2008 and 2010–2013 were analyzed to characterize migration routes and link movements to subsequent survival at an array 250 km further along the marine migration pathway. Both species exhibited disproportionate use of the most eastern route in the Strait of Georgia (Malaspina Strait). While many smolts moved across the northern Strait of Georgia acoustic array with no indication of long-term milling or large-scale east-to-west movements, large proportions (20–40% of sockeye and 30–50% of steelhead) exhibited a different behavior, apparently moving in a westward or counterclockwise pattern. Variability in migratory behavior for both species was linked to subsequent survival through the Strait of Georgia. Survival for both species was influenced by initial east-to-west location, and sockeye were further influenced by migration timing and duration of time spent near the northern Strait of Georgia array. Westward movements result in a net transport of smolts from Malaspina Strait to the Strait of Georgia, particularly for steelhead. Counterclockwise movements may be due to the currents in this area during the time of outmigration, and the higher proportion of steelhead smolts exhibiting this counterclockwise behavior may reflect a greater exposure to wind-altered currents for the more surface-oriented steelhead. Our results provide an empirical example of how movements can affect migration survival, for which examples remain rare in movement ecology, confirming that variability in movements themselves are an important part of the migratory process. Public Library of Science 2015-10-09 /pmc/articles/PMC4599731/ /pubmed/26451837 http://dx.doi.org/10.1371/journal.pone.0139269 Text en © 2015 Furey et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Furey, Nathan B.
Vincent, Stephen P.
Hinch, Scott G.
Welch, David W.
Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts
title Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts
title_full Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts
title_fullStr Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts
title_full_unstemmed Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts
title_short Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts
title_sort variability in migration routes influences early marine survival of juvenile salmon smolts
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4599731/
https://www.ncbi.nlm.nih.gov/pubmed/26451837
http://dx.doi.org/10.1371/journal.pone.0139269
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