Factors influencing production loss in salmonid farming

Using a unique dataset, this paper investigates factors influencing production loss in Norwegian salmonid farming. The factors can be grouped into fish-specific factors (e.g. species, genetics, and generation), input factors (e.g. vaccines and smolt quality), environmental factors (e.g. geographical location), and managerial factors (e.g. ownership). The most important result is most likely that production losses to a large extent are explainable, as our best model has an R2 as high as 0.826. This implies that it is possibile to reduce production losses significantly. For the specific factors, vaccines reduce production loss, but their effect varies by production site. Production loss also varies with which smolt plant is providing juvenile fish, indicating that there is systematic quality variation among the providers of smolt. There is also significant variation in production loss between companies and production sites, and on average production losses are lower for larger companies and sea sites holding larger numbers of fish. An important point is that while some factors explaining production loss are controlled by the individual company, others are beyond their control. Some of these external factors are related to the regulatory system.publishedVersio