Canada’s first-ever Code of Practice for fish is open for public comment

In the wild, salmon travel huge distances (some travel over 3,000 kilometers) to migrate, and their natural behaviours reflect the large ranges they are used to traveling. But in captivity, salmon have a small fraction of this space. At the very least, farmed salmon should be provided with room to swim around (no crowding) and be given with opportunities for exercise. This can be done by providing areas with a faster current to allow fish to swim.

Stocking densities (also called ‘bio-density’) on fish farms are variable and can depend on the system (land-based vs open water), tidal range and other factors. However, stocking density is an important welfare consideration and research shows when tanks are too crowded, injuries can result, such as pelvic fin damage and cataracts. There are production impacts to overcrowding as well – some research has shown lower feed intake when stock density is high.

Fish are regularly handled in the aquaculture industry for procedures such as vaccination and grading. Handling is stressful for fish, and they are more susceptible to injuries depending on their age, health or because of environmental factors. These conditions need to be considered when setting a standard for fish welfare during handling.

Like other farmed animals, fish may face unnecessary stress and suffering before and during slaughter. The most humane method is to render the animals unconscious prior. CO2 is a commonly used method, but it is widely considered inhumane because it is a very painful and slow method of slaughter for fish. In parts of Canada, ice-slurry slaughter is another inhumane method still used where fish are placed on ice fully conscious to slowly asphyxiate.

The most humane method is the process of electrical stunning where an electrical current is passed through the water causing death almost instantly.

Salmon are typically denied food on farms prior to husbandry procedures and slaughter for welfare reasons (such as reduced injury and mortality) and for food hygiene reasons. In the wild, salmon can experience short periods of food deprivation and have adapted to this. However, longer periods cause stress. Thus, salmon should not be subject to more than 48 hours of food deprivation. This is generally considered acceptable from a welfare perspective. The Code, however, permits up to seven days of food deprivation which is unacceptable.

Some fish farms use 24-hour lighting which is associated with many negative welfare effects including neurological development issues, lowered bone strength, poor smolt quality, failed smoltification, and failed spawning. Higher welfare systems should have lighting systems in place that gradually change in light intensity. However, the Code only requires this for newly built systems not existing systems; it should apply retroactively to existing fish farms.

Sea lice has been an important environmental concern with fish farms for many years, but it is also a welfare issue, as infestation can cause pain and suffering. While the recommendations and requirements in the code focus on the removal of sea lice and monitoring sea lice levels in the population, there is no mention of what personnel should do when they come across an individual fish or a number of fish that are covered in sea lice and are thus likely experiencing pain or suffering. For example, the RSPCA welfare standards for farmed Atlantic salmon states that “any fish with severe physical damage caused by sea lice grazing must be removed and dispatched humanely without delay”. There should be a similar statement in this Code.