Empirical analyses of the length, weight, and condition of adult Atlantic salmon on return to the Scottish coast between 1963 and 2006

P. J. Bacon, S. C.F. Palmer, J. C. MacLean, G. W. Smith, B. D.M. Whyte, W. S.C. Gurney, A. F. Youngson

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

Sea age, size, and condition of adult Atlantic salmon (Salmo salar) are prime determinants of individual, and hence population, productivity. To elucidate potential mechanisms, 151 000 records of salmon returning to six Scottish coastal sites over 44 years were analysed for length, weight, and condition, by site, sex, sea age, and river age. After correcting for capture effort biases, all sites showed seasonal increases in length and weight for both 1 sea winter (1SW) and 2SW fish. However, whereas condition increased slightly with season for 2SW, it decreased notably for 1SW. Sites showed common decadal trends in length, weight, and condition. Within years, length and weight residuals from trends were coherent across sites, but residuals from condition trends were not. Rates of seasonal condition change also showed decadal trends, dramatically different between sea ages, but common across sites within sea-age groups. Longer salmon were disproportionately heavy in all seasons. 1SW condition was markedly lower in 2006. Detrended correlations with oceanic environmental variables were generally not significant, and always weak. A published correlation between the condition of 1SW salmon caught at a single site and sea surface temperatures in the Northeast Atlantic could not be substantiated for any of the six fisheries over the wider time-scales examined.

Original languageEnglish
Pages (from-to)844-859
Number of pages16
JournalICES Journal of Marine Science
Volume66
Issue number5
Early online date17 Apr 2009
DOIs
Publication statusPublished - 1 Jun 2009

Fingerprint

Salmo salar
coasts
coast
salmon
winter
surface temperature
fisheries
sea
environmental factors
rivers
gender
fish
sea surface temperature
fishery
timescale
productivity
trend
river

Keywords

  • Climate change
  • Condition
  • Marine environment
  • NAO
  • Salmo salar
  • Sea surface temperature

ASJC Scopus subject areas

  • Oceanography
  • Ecology, Evolution, Behavior and Systematics
  • Ecology
  • Aquatic Science

Cite this

Empirical analyses of the length, weight, and condition of adult Atlantic salmon on return to the Scottish coast between 1963 and 2006. / Bacon, P. J.; Palmer, S. C.F.; MacLean, J. C.; Smith, G. W.; Whyte, B. D.M.; Gurney, W. S.C.; Youngson, A. F.

In: ICES Journal of Marine Science, Vol. 66, No. 5, 01.06.2009, p. 844-859.

Research output: Contribution to journalArticle

Bacon, P. J. ; Palmer, S. C.F. ; MacLean, J. C. ; Smith, G. W. ; Whyte, B. D.M. ; Gurney, W. S.C. ; Youngson, A. F. / Empirical analyses of the length, weight, and condition of adult Atlantic salmon on return to the Scottish coast between 1963 and 2006. In: ICES Journal of Marine Science. 2009 ; Vol. 66, No. 5. pp. 844-859.
@article{7084ef514ef2405d91b3e836f221b3f4,
title = "Empirical analyses of the length, weight, and condition of adult Atlantic salmon on return to the Scottish coast between 1963 and 2006",
abstract = "Sea age, size, and condition of adult Atlantic salmon (Salmo salar) are prime determinants of individual, and hence population, productivity. To elucidate potential mechanisms, 151 000 records of salmon returning to six Scottish coastal sites over 44 years were analysed for length, weight, and condition, by site, sex, sea age, and river age. After correcting for capture effort biases, all sites showed seasonal increases in length and weight for both 1 sea winter (1SW) and 2SW fish. However, whereas condition increased slightly with season for 2SW, it decreased notably for 1SW. Sites showed common decadal trends in length, weight, and condition. Within years, length and weight residuals from trends were coherent across sites, but residuals from condition trends were not. Rates of seasonal condition change also showed decadal trends, dramatically different between sea ages, but common across sites within sea-age groups. Longer salmon were disproportionately heavy in all seasons. 1SW condition was markedly lower in 2006. Detrended correlations with oceanic environmental variables were generally not significant, and always weak. A published correlation between the condition of 1SW salmon caught at a single site and sea surface temperatures in the Northeast Atlantic could not be substantiated for any of the six fisheries over the wider time-scales examined.",
keywords = "Climate change, Condition, Marine environment, NAO, Salmo salar, Sea surface temperature",
author = "Bacon, {P. J.} and Palmer, {S. C.F.} and MacLean, {J. C.} and Smith, {G. W.} and Whyte, {B. D.M.} and Gurney, {W. S.C.} and Youngson, {A. F.}",
note = "We thank all the owners and occupiers of the net fisheries at the North Esk, Strathy Point, Spey, Dee, Tay, and Tweed sites who kindly allowed our staff long-term access to their salmon catches, so to obtain the subsamples from which these data were derived. The Atlantic Salmon Trust provided grant 2007/11 to defray some of the costs of the statistical analysis, and the EU FinE project also part-funded some final details of the work. We thank Ronald Campbell, Ross Gardiner, John Gilbey, Sarah Hughes, Philip McGinnity, and Richard Shelton for discussions and constructive comments, and two anonymous referees for valued comments on the submitted draft.",
year = "2009",
month = "6",
day = "1",
doi = "10.1093/icesjms/fsp096",
language = "English",
volume = "66",
pages = "844--859",
journal = "ICES Journal of Marine Science",
issn = "1054-3139",
publisher = "Oxford University Press",
number = "5",

}

TY - JOUR

T1 - Empirical analyses of the length, weight, and condition of adult Atlantic salmon on return to the Scottish coast between 1963 and 2006

AU - Bacon, P. J.

AU - Palmer, S. C.F.

AU - MacLean, J. C.

AU - Smith, G. W.

AU - Whyte, B. D.M.

AU - Gurney, W. S.C.

AU - Youngson, A. F.

N1 - We thank all the owners and occupiers of the net fisheries at the North Esk, Strathy Point, Spey, Dee, Tay, and Tweed sites who kindly allowed our staff long-term access to their salmon catches, so to obtain the subsamples from which these data were derived. The Atlantic Salmon Trust provided grant 2007/11 to defray some of the costs of the statistical analysis, and the EU FinE project also part-funded some final details of the work. We thank Ronald Campbell, Ross Gardiner, John Gilbey, Sarah Hughes, Philip McGinnity, and Richard Shelton for discussions and constructive comments, and two anonymous referees for valued comments on the submitted draft.

PY - 2009/6/1

Y1 - 2009/6/1

N2 - Sea age, size, and condition of adult Atlantic salmon (Salmo salar) are prime determinants of individual, and hence population, productivity. To elucidate potential mechanisms, 151 000 records of salmon returning to six Scottish coastal sites over 44 years were analysed for length, weight, and condition, by site, sex, sea age, and river age. After correcting for capture effort biases, all sites showed seasonal increases in length and weight for both 1 sea winter (1SW) and 2SW fish. However, whereas condition increased slightly with season for 2SW, it decreased notably for 1SW. Sites showed common decadal trends in length, weight, and condition. Within years, length and weight residuals from trends were coherent across sites, but residuals from condition trends were not. Rates of seasonal condition change also showed decadal trends, dramatically different between sea ages, but common across sites within sea-age groups. Longer salmon were disproportionately heavy in all seasons. 1SW condition was markedly lower in 2006. Detrended correlations with oceanic environmental variables were generally not significant, and always weak. A published correlation between the condition of 1SW salmon caught at a single site and sea surface temperatures in the Northeast Atlantic could not be substantiated for any of the six fisheries over the wider time-scales examined.

AB - Sea age, size, and condition of adult Atlantic salmon (Salmo salar) are prime determinants of individual, and hence population, productivity. To elucidate potential mechanisms, 151 000 records of salmon returning to six Scottish coastal sites over 44 years were analysed for length, weight, and condition, by site, sex, sea age, and river age. After correcting for capture effort biases, all sites showed seasonal increases in length and weight for both 1 sea winter (1SW) and 2SW fish. However, whereas condition increased slightly with season for 2SW, it decreased notably for 1SW. Sites showed common decadal trends in length, weight, and condition. Within years, length and weight residuals from trends were coherent across sites, but residuals from condition trends were not. Rates of seasonal condition change also showed decadal trends, dramatically different between sea ages, but common across sites within sea-age groups. Longer salmon were disproportionately heavy in all seasons. 1SW condition was markedly lower in 2006. Detrended correlations with oceanic environmental variables were generally not significant, and always weak. A published correlation between the condition of 1SW salmon caught at a single site and sea surface temperatures in the Northeast Atlantic could not be substantiated for any of the six fisheries over the wider time-scales examined.

KW - Climate change

KW - Condition

KW - Marine environment

KW - NAO

KW - Salmo salar

KW - Sea surface temperature

UR - http://www.scopus.com/inward/record.url?scp=66249109590&partnerID=8YFLogxK

U2 - 10.1093/icesjms/fsp096

DO - 10.1093/icesjms/fsp096

M3 - Article

AN - SCOPUS:66249109590

VL - 66

SP - 844

EP - 859

JO - ICES Journal of Marine Science

JF - ICES Journal of Marine Science

SN - 1054-3139

IS - 5

ER -