The demand for trout as a sport fish far exceeds the supply in heavily populated regions. This situation, particularly in the United States, has resulted in a massive program by state and federal agencies to raise trout to acceptable size and to stock them in heavily fished waters. Such an artificial abundance, however, is a poor substitute for natural trout fishing.
Except for the pikes, the remaining freshwater salmoniforms are too small or too rare to be significant sport fish, but most are considered excellent food fish. The oceanic salmoniforms have little direct importance to man; because of their tremendous abundance, however, they form a vital link in the food chain of the oceans, providing forage for valuable predator species such as the tuna. Many of the deep-sea salmoniforms undertake daily vertical migrations, rising toward the surface layer of the ocean at night for feeding. This vertical migration exposes them to predation by larger fishes and functions in the recycling of energy in the ocean by elevating energy accumulated in the lower depths (in the bodies of the small salmoniforms) and making it available to large predators in the upper zones.
