Precision and accuracy of Dahl-Lea back-calculated smolt lengths from adult scales of Atlantic salmon (Salmo salar L.)

• Published in: Journal of Fish Biology
• Main Authors: Hanson, Nora N, Smith, Gordon W, Middlemas, Stewart J, Todd, Christopher David
• Other Authors: University of St Andrews.School of Biology, University of St Andrews.Marine Alliance for Science & Technology Scotland, University of St Andrews.Scottish Oceans Institute
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2019
• Subjects: Allometry; Back-calculation; Circuli; Growth; Increment analysis; Salmo salar; QH301 Biology; SH Aquaculture. Fisheries. Angling; NDAS; QH301; SH; Atlantic salmon
• Online Access: https://hdl.handle.net/10023/18930; https://doi.org/10.1111/jfb.13863

Using tagged and recaptured Atlantic salmon Salmo salar (n = 106) the present analysis shows that the most commonly applied linear back-calculation method for estimating past length, the Dahl-Lea method, resulted in overestimation of the length of large smolts and underestimation of small smolts. A correction equation (y = 0.53x + 6.23) for estimating true smolt length (y) from lengths back-calculated from adult scale measures (x) to account for these systematic discrepancies is proposed. Peer reviewed