Validating Atlantic salmon (Salmo Salar) scale reading by genetic parent assignment and PIT-tagging.

ABSTRACT: Understanding changes in abundance and survival in Atlantic salmon populations requires knowledge of growth rates and age. Salmon are typically aged through scale reading, but such estimates are rarely validated against age-verified fish from the wild. Here, we present a unique dataset of scales from 254 PIT-tagged Atlantic salmon with known sea-age. In addition, the freshwater age is known for 81 of these fish, through genetic parent-offspring identification. This dataset was used to estimate precision and bias in age readings and back-calculated length, as estimated by three independent experienced salmon scale readers. Overall, readers had an accuracy of 97.1% for sea-age and 71.7% for freshwater-age. For sea-age, scale reading was less accurate for salmon that had spent 2 or more years

SUBMITTER: Utne KR 

PROVIDER: S-EPMC12061416 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature