Trends during development of Scottish salmon farming: An example of sustainable intensification?

Abstract

Commercial farming of Atlantic salmon in Scotland started in 1969 and has since expanded to produce N 179,000 t year −1 . A government department has published annual statistics and information on the seawater and freshwater sub-sectors of the Scottish salmon farming industry since 1979, and this review collates and dis cusses metrics covering aspects of production, farm sites and systems, fish performance, socio-economics and en vironmental pressures. Trends illustrated in this case study of aquaculture development include: initial increases in numbers of farms and companies, followed by decreases due to industry consolidation; increases in average farm size, and productivity of systems and employees; increases in survival, size at age and productivity of fish (yield per smolt, ova per broodstock); reduced dependence on wild stocks for ova. This case study also illustrates the importance of disease management, control of biological processes to overcome natural seasonality (i.e. pro duction of out-of-season smolt), and the international nature of aquaculture. Improvements in fish survival, growth and productivity are attributed to progress in vaccination and health management (including fallowing), husbandry, system design, feed formulation and provision, and introduction of technology and mechanisation. Salmon farming is discussed in relation to the challenging strategy of "sustainable intensification". Improved growth and survival over a period of increasing rearing unit size, farm size and output and decreasing relative staff input counters the common assumption that intensification compromises animal welfare. The value of cap turing time series data on industry wide metrics is illustrated as it enables identification of trends, underperformance and bench-marking, as well as assessment of resource use efficiency, environmental pres sures, and ultimately sustainability. Statement of relevance: This review is an original collation of a comprehensive set of time series of official statistics on an entire, discrete and regionally important sector of commercial aquaculture.Crown

Population biology of infectious diseases shared by wild and farmed fish

“…Domesticated fish populations have also become more resistant to disease outbreaks via selective breeding as well as improved husbandry and site selection that reduce sources of stress that can make fish more prone to disease (Pohlenz and Gatlin 2014;Ellis et al 2016;Naslund and Johnsson 2016).…”

“…ing increasingly coordinated at regional scales Ellis et al 2016). Coordination of the timing of parasite treatment on farms to minimize parasite levels during periods of wild fish migrations may effectively protect wild fish without increasing the overall frequency of drug use Rogers et al 2013).…”

Spatial overlap of shark nursery areas and the salmon farming industry influences the trophic ecology of Squalus acanthias on the southern coast of Chile

“…In the past three decades, salmonid aquaculture in Chile has experienced an explosive growth and diversification driven by the use of intensive farming techniques (Buschmann et al., ; Oddone, Paesch, & Norbis, ) and the introduction of several different salmonid species (Correa & Gross, ). Although this growth has placed Chile as the second most important salmon exporter worldwide (Ellis et al., ), it has also raised criticisms and concerns related to its negative environmental effects (Buschmann et al., , ; Soto & Norambuena, ). The marine phase of salmon aquaculture is conducted in an open water net‐system that allows the discharge of large quantities of pollutants, mainly organic matter, nitrogen, and phosphorus into water bodies and the sea floor (Paudel et al., ).…”

In vitro CULTURE OF FISH LOUSE (Lepeoptheirus salmonis) IN ATLANTIC SALMON (Salmo salar L. ) HOST CELL LINE

“…The farmed salmon industry has grown substantially in the past 40 years and today approximately 60% of the world's salmon production is farmed and rest from wild (Ellis et al, 2016). The Atlantic salmons are most susceptible to Lepeophtherius infection as compared to other salmon species (Johnson & Albright, 1992).…”