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Article
Back-Calculation of Fish Length from Scales: Empirical Comparison of Proportional Methods
Transactions of the American Fisheries Society
  • Clay L. Pierce, National Biological Service
  • Joseph B. Rasmussen, McGill University
  • William C. Leggett, Queens University - Kingston
Document Type
Article
Publication Version
Published Version
Publication Date
1-1-1996
DOI
10.1577/1548-8659(1996)125<0889:BCOFLF>2.3.CO;2
Abstract

We compared three proportional back-calculation methods for scales using data sets for pumpkinseeds Lepomis gibbosus and golden shiners Notemigonus crysoleucas from 10 southern Quebec lakes, and we validated back-calculations by comparing them with observed lengths at lime of annulus formation. Ordinary least-squares regression (OR) was compared with geometric mean regression (GMR) for describing body-scale relationships. Although minor differences were detected in body-scale regressions among lakes, pooling data across lakes yielded linear bodyscale relationships with very high r2. Differences between OR and GMR body-scale relationships were negligible in both species. Likewise, all back-calculation methods produced equivalent results. Back-calculated lengths generally corresponded well with observed lengths in all pumpkinseeds age-classes and in golden shiners older than 1 year. Observed lengths were often greater than back-calculated lengths for age-1 golden shiners. Our results, indicating little or no difference among methods, contradict recent reviews claiming substantial disagreement among methods. Tighter body-scale relationships in our data sets than in previous studies appear to explain this contradiction. We suggest that light body-scale relationships are attainable for many species, obviating concern over which proportional back-calculation method is chosen.

Comments

This article is from Transactions of the American Fisheries Society 125 (1996): 889, doi:10.1577/1548-8659(1996)125<0889:BCOFLF>2.3.CO;2.

Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Language
en
File Format
application/pdf
Citation Information
Clay L. Pierce, Joseph B. Rasmussen and William C. Leggett. "Back-Calculation of Fish Length from Scales: Empirical Comparison of Proportional Methods" Transactions of the American Fisheries Society Vol. 125 Iss. 6 (1996) p. 889 - 898
Available at: http://works.bepress.com/clay_pierce/51/