Several processes in fish production involve handling, which will always be stressful for the fish. It can be vaccination, lice treatment, transport and other factors. Stress increases the risk of illness and can ultimately lead to increased mortality.  

Stress is unfavorable for all animals, both on land and in water. By using anesthesia, you can minimize the acute stress during handling, in addition to reducing the chronic stress afterwards. Anesthetizing can also help to make the process itself easier, as calm fish are easier to handle.