Farmed salmon is mainly produced in Norway, Chile, Scotland, the Faroe Islands, Ireland, Iceland, Canada, the USA, Tasmania, and New Zealand. This is due to biological limitations, seawater temperature requirements, and other natural limitations.
One of the great enemies of salmon growth is changes in seawater temperature. In winter and spring salmon grow more slowly as the water is colder. Therefore, production normally peaks around the end of the year and gets to its lower limits in mid-summer.
Indistinctly, with high sea temperatures the risk of disease increases, and with temperatures below zero degrees, mass mortality becomes more likely.