Salmonidae

The family Salmonidae, commonly known as salmon and trout, comprises fish that originally evolved in clear, cold water. These fish require pure, well-oxygenated, cold water, making them sensitive to environmental degradation.1

Salmonids are found in freshwater environments across the Northern Hemisphere, from tributaries of the Arctic Ocean to parts of North Africa and Taiwan. Some species, like the Arctic char, are the most northerly freshwater fish. Many salmonids, such as trout and salmon, have an anadromous life cycle, meaning they spawn in freshwater but migrate to the sea to feed and mature. This allows them to inhabit a wider range of colder regions.2

Salmon and trout are highly valued as both sport and commercial fish. Significant efforts are made by governments and industries to maintain and increase their populations through hatcheries and stocking programs. Pacific salmon species, such as sockeye, coho, chum, and chinook, live most of their lives in the ocean but return to their birth streams to spawn, often using their sense of smell and Earth's magnetic field to navigate. After spawning, Pacific salmon typically die, while some Atlantic salmon can spawn multiple times.34