Notes on the causes of salmon mortality

Fish health and welfare are at the heart of successful Scottish salmon farming. It is in everyone’s interests to operate to the highest of welfare standards.

The reproductive strategy of fish is to produce a large number of offspring so that a proportion will survive to adulthood. Fish, including farmed fish, are subject to a number of pressures in the environment, particularly naturally present pathogens. It can therefore be expected that some fish will experience challenges to their health. Farming fish in a controlled environment removes some of the environmental pressures and improves their survival rate.

The Scottish salmon industry works to ensure the highest possible survival rate for their salmon. Salmon farmers and fish health professionals ensure they adopt the most stringent standards of biosecurity and best practice where fish health and welfare are concerned. Dedicated teams of fish health professionals and specialist veterinarians continually monitor the fish and develop management strategies to protect against health challenges and to respond rapidly, if needed.

In all animal production some losses, though regrettable, do occur.

Here we provide further information to support the data being published in the monthly, farm-by-farm, report of fish mortality.

Causes of mortality

Causes of salmon mortality are varied. Our dataset identifies reasons for mortality as follows: