The limiting factor for trout was neither space nor drift, but rather the number of feeding sites. Bachman studied brown trout, but several other studies have shown similar behavior for rainbows. In the light of our understanding of trout behavior, lets consider some common management strategies. Stocking hatchery fry or fingerlings adds no more fish, but may dilute the wild gene pool if any hatchery fish survive long enough to spawn. A natural stream has a limited production capacity.
Wild trout are extremely wary and difficult to catch.
Readily accessible trout streams have a far greater biomass of anglers than of fish. For the average angler to catch trout, the stream must be stocked with catchable-sized trout. Fishing can be maintained near human population centers. Relatively unskilled anglers catch fish. Because of the rapid catch, fish can be planted and harvested from waters that will be too warm for trout later in summer.