Abstract
The transition from hatchery to sea is a crucial stage in Atlantic salmon aquaculture. The initial post‐transfer phase is challenged with high mortality rates. This vulnerable phase not only impacts farm productivity but also raises significant concerns for fish welfare and industry sustainability. Although previous research has highlighted a connection between hatchery conditions and smolt‐related mortality, the specific risk factors and their underlying mechanisms remain insufficiently explored. This study aimed at capturing the perceptions of hatchery managers and fish health personnel regarding key risk factors for post‐sea transfer mortality. A qualitative approach was used, employing semi‐structured interviews that explored fish welfare, smolt mortality, and both organizational and husbandry practices. Analysis of the interviews revealed several potential risk factors, which could be grouped into husbandry factors, organizational factors, diseases, water quality, factors at sea transfer, and farm factors. Notably, most identified risks were linked to production practices, often spanning multiple categories. Participants pointed to the increasing intensity of production, driven by new smolt protocols, as a source of emerging challenges within an already complex system. Poor husbandry practices were frequently cited as leading to suboptimal smoltification and subsequent high post‐transfer mortality. Moreover, respondents emphasized the critical importance of organizational focus on fish health and welfare, and the need to understand the underlying causes of mortality. Importantly, most risk factors were attributed to decisions made within farming companies, at either the hatchery or organizational level, suggesting that many of these risks could be mitigated through targeted management if they are clearly described, understood, and prioritized.