Scale Growth Analysis of Atlantic salmon (Salmo salar Linnaeus) Unlocking Environmental Histories
Peer Reviewed Atlantic salmon (Salmo salar L.) populations have declined rapidly in recent years across all geographical ranges with populations becoming extinct within certain areas. Direct observation of the salmon’s life is difficult and costly; therefore, scales remain the most widely used mater...
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ftmarineinst:oai:oar.marine.ie:10793/1389 2023-05-15T15:30:15+02:00 Scale Growth Analysis of Atlantic salmon (Salmo salar Linnaeus) Unlocking Environmental Histories Thomas, K. 2018 http://hdl.handle.net/10793/1389 en eng Galway-Mayo Institute of Technology Thomas, K. (2018). Scale Growth Analysis of Atlantic salmon (Salmo salar Linnaeus) Unlocking Environmental Histories. Galway-Mayo Institute of Technology http://hdl.handle.net/10793/1389 Scale Growth atlantic salmon Environmental histories Thesis 2018 ftmarineinst 2022-07-27T09:39:15Z Peer Reviewed Atlantic salmon (Salmo salar L.) populations have declined rapidly in recent years across all geographical ranges with populations becoming extinct within certain areas. Direct observation of the salmon’s life is difficult and costly; therefore, scales remain the most widely used material to indirectly assess and monitor the recent changes in growth. Growth marks (circuli) in scales of Atlantic salmon are used to estimate age and to reconstruct growth histories. This thesis investigated mechanisms of circuli formation and the causes of variation in scale growth measurements. Comparison of scales from multiple body locations (Chapter 2) showed that growth, size and shape measurements varied significantly between body locations. Scale measurements taken from the sampling location recommended by ICES were sufficiently correlated with measurements from two adjacent locations in the posterior body region to facilitate conversion; calibration equations are presented for this purpose. Scale measurements from the anterior body region were highly variable and their use is not recommended. Scale size measurements from the recommended sampling location and from the two adjacent locations in the posterior body region were sufficiently correlated with fish fork length. Differences in scale size could potentially be used to determine the body location from which a scale was most likely sampled if this information has not been recorded (e.g. in archived scale collections); regression equations are presented for this purpose. Analysis of scales from experimentally reared Atlantic salmon post-smolts (Chapters 3 and 4), showed that scale growth and circuli number was proportional to fish growth under a range of different water temperatures and feeding conditions, justifying the use of these measurements as a proxy for growth. The rate of circuli deposition varied between temperature and feeding treatments and circuli number was proportional to cumulative degree day. Narrow inter-circuli spacings were observed ... Thesis Atlantic salmon Salmo salar Marine Institute Open Access Repository |
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English |
topic |
Scale Growth atlantic salmon Environmental histories |
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Scale Growth atlantic salmon Environmental histories Thomas, K. Scale Growth Analysis of Atlantic salmon (Salmo salar Linnaeus) Unlocking Environmental Histories |
topic_facet |
Scale Growth atlantic salmon Environmental histories |
description |
Peer Reviewed Atlantic salmon (Salmo salar L.) populations have declined rapidly in recent years across all geographical ranges with populations becoming extinct within certain areas. Direct observation of the salmon’s life is difficult and costly; therefore, scales remain the most widely used material to indirectly assess and monitor the recent changes in growth. Growth marks (circuli) in scales of Atlantic salmon are used to estimate age and to reconstruct growth histories. This thesis investigated mechanisms of circuli formation and the causes of variation in scale growth measurements. Comparison of scales from multiple body locations (Chapter 2) showed that growth, size and shape measurements varied significantly between body locations. Scale measurements taken from the sampling location recommended by ICES were sufficiently correlated with measurements from two adjacent locations in the posterior body region to facilitate conversion; calibration equations are presented for this purpose. Scale measurements from the anterior body region were highly variable and their use is not recommended. Scale size measurements from the recommended sampling location and from the two adjacent locations in the posterior body region were sufficiently correlated with fish fork length. Differences in scale size could potentially be used to determine the body location from which a scale was most likely sampled if this information has not been recorded (e.g. in archived scale collections); regression equations are presented for this purpose. Analysis of scales from experimentally reared Atlantic salmon post-smolts (Chapters 3 and 4), showed that scale growth and circuli number was proportional to fish growth under a range of different water temperatures and feeding conditions, justifying the use of these measurements as a proxy for growth. The rate of circuli deposition varied between temperature and feeding treatments and circuli number was proportional to cumulative degree day. Narrow inter-circuli spacings were observed ... |
format |
Thesis |
author |
Thomas, K. |
author_facet |
Thomas, K. |
author_sort |
Thomas, K. |
title |
Scale Growth Analysis of Atlantic salmon (Salmo salar Linnaeus) Unlocking Environmental Histories |
title_short |
Scale Growth Analysis of Atlantic salmon (Salmo salar Linnaeus) Unlocking Environmental Histories |
title_full |
Scale Growth Analysis of Atlantic salmon (Salmo salar Linnaeus) Unlocking Environmental Histories |
title_fullStr |
Scale Growth Analysis of Atlantic salmon (Salmo salar Linnaeus) Unlocking Environmental Histories |
title_full_unstemmed |
Scale Growth Analysis of Atlantic salmon (Salmo salar Linnaeus) Unlocking Environmental Histories |
title_sort |
scale growth analysis of atlantic salmon (salmo salar linnaeus) unlocking environmental histories |
publisher |
Galway-Mayo Institute of Technology |
publishDate |
2018 |
url |
http://hdl.handle.net/10793/1389 |
genre |
Atlantic salmon Salmo salar |
genre_facet |
Atlantic salmon Salmo salar |
op_relation |
Thomas, K. (2018). Scale Growth Analysis of Atlantic salmon (Salmo salar Linnaeus) Unlocking Environmental Histories. Galway-Mayo Institute of Technology http://hdl.handle.net/10793/1389 |
_version_ |
1766360691650854912 |