Inland, this fish favours natural stream channels with rapids, pools and gravelly bottoms in which hatchlings can hide from predators. The fish prefer cool water that is free from chemical and organic pollution, and that maintains temperatures between 15°C and 25°C in summer.

When living in the Bay of Fundy itself, these salmon prefer relatively stable water temperatures-between 1°C and 15°C year round. It is possible that the salmon's low marine survival may in part be due to fluctuations in sea-surface water temperature.

With its pointed head, well-developed teeth and silvery sides, the Atlantic salmon is instantly recognizable. When at sea, the salmon's back varies through shades of brown, green and blue, and it has numerous black spots scattered along its body. When spawning, the fish becomes bronze-purple in colour and develops reddish spots on head and body.