Changes in growth and migration patterns of sea trout before and after the introduction of Atlantic salmon farming

Marine growth has strong implications for reproductive potential and ultimate fitness of sea trout. Hence, the effects of anthropogenic factors on marine growth are important when evaluating population responses and implementing management measures. Temporal changes in growth patterns of sea trout from three Norwegian and two Irish watercourses were examined, covering time spans of 25–65 years. Elemental chemistry Ba:Ca profiles and visual reading of fish scales were used to estimate smolt length and lifetime growth after first sea entry. Reduced growth after the first sea entry coincided with periods of nearby (