Understanding how farmed salmonids sense and respond to their environment is key to securing animal welfare and efficient production. However, hearing has rarely received attention, despite the omnipresence of underwater sound and its potential effects. We describe how and what salmonids hear, and explore how hearing may differ between wild and farmed conspecifics. We then conduct two systematic reviews, to: (1) understand the...

Periods of fasting occur for a multitude of reasons in Atlantic salmon aquaculture. Feed withdrawal is widely used prior to transport, parasite treatments, preslaughter and for depuration purposes in recirculating aquaculture systems. Voluntary fasting is a coping response when fish have poor health or are exposed to poor farm environments. Owing to increased attention to animal welfare in aquaculture, concerns have been raise...

Surface‐based cages are the dominant production technology for the marine finfish aquaculture industry. However, issues such as extreme weather events, poor environmental conditions, interactions with parasites, and conflicts with other coastal users are problematic for surface‐based aquaculture. Submerged cages may reduce many of these problems and commercial interest in their use has increased. However, a broad synthesis of...

Ectoparasitic salmon lice ( Lepeophtheirus salmonis ) present a major challenge to Atlantic salmon ( Salmo salar ) aquaculture. The demand for effective louse control has produced diverse management strategies. These strategies essentially impose novel selection pressures on parasite populations, driving the evolution of resistance. Here we assess the potential for salmon lice to adapt to current prevention and control methods...

A variety of tagging techniques are now available to monitor fish behaviour, physiology and their environmental experience. Tagging is frequently used in aquaculture research to monitor free‐swimming individuals within farmed populations. However, for information gathered from tagged fish to be representative of farmed populations, tagging must not fundamentally affect fish behaviour, physiology or survival. Here, we systemati...

An understanding of behaviour is used in zoos, laboratories and agriculture to reduce stressful aspects of the captive environment for animals. While fish are one of the most cultivated of all vertebrate groups, incorporating their behaviour into production management has proved elusive. Here, we evaluate the current evidence base relating to use of (i) innate behaviours of fish and (ii) their ability to learn new behaviours v...

To accommodate further growth in the Atlantic salmon aquaculture industry, new production sites may well be established at more exposed locations along the coast or even offshore. Here, fish will encounter strong currents and powerful waves, which are avoided at traditional sheltered locations. Exposed locations offer several advantages and necessitate new technological advancements. However, the most crucial question is wheth...

The Atlantic salmon aquaculture industry still struggles with ectoparasitic sea lice despite decades of research and development invested into louse removal methods. In contrast, methods to prevent infestations before they occur have received relatively little research effort, yet may offer key benefits over treatment‐focused methods. Here, we summarise the range of potential and existing preventative methods, conduct a meta‐a...

With the expansion of Atlantic salmon aquaculture, the economic and ecological impacts of salmon lice ( Lepeophtheirus salmonis ) has increased. Norway battles this problematic parasite with various control and preventative methods within farms. We analysed two national‐level databases to examine the number of operations reported each year from 2012 to 2017 and salmon mortality rates attributable to each operation type. From 2...

Host behaviour can prevent infection and moderate the fitness of parasites. Antiparasite behaviours are prevalent in many host–parasite systems and occur over fine or broad scales. With global growth in aquaculture production and the associated proliferation of parasites in farming systems, the behaviour of the fish being farmed has seldom been investigated in relation to parasites. Epidemics and outbreaks of parasites are pre...

A semantic model for overall welfare assessment of Atlantic salmon reared in sea cages is presented. The model, called SWIM 1.0, is designed to enable fish farmers to make a formal and standardized assessment of fish welfare using a set of selected welfare indicators. In order to cover all welfare relevant aspects from the animals’ point of view and to create a science‐based tool we first identified the known welfare needs of...