Fish stocking is the practice of raising fish in a hatchery and releasing them into a river, lake, or the ocean to supplement existing populations, or to create a population where none exists. Stocking may be done for the benefit of commercial, recreational, or tribal fishing, but may also be done to restore or increase a population of threatened or endangered fish in a body of water closed to fishing.
Fish stocking is a practice that dates back hundreds of years.
In the United States, the practice of stocking non-native fish for sport and food was just beginning in 1871, when the US Fish Commission was established. The head of the new agency, Spencer Fullerton Baird, was tasked to research "the decrease of the food fishes of the seacoasts and the lakes of the United States and to suggest remedial measures." Baird made his headquarters at Woods Hole on Cape Cod, Massachusetts. There, his team of scientists and researchers conducted studies on striped bass, blue fish, and many other commercial and sport fish. They compiled their research into a 255-page report on United States fish resources. Congress granted the team 15,000 dollars to develop food fish stocks, and non-native fish such as rainbow trout, salmon, striped bass, and carp, were subsequently introduced successfully into United States lakes and rivers.
Today, much more thought is put into introducing non-native species. Non-native species can severely damage the populations of fragile native species. Stocking is used to restore native species to waters where they have been overfished or can no longer breed. "Give and take" stocking practices are those where fish are stocked only to be fished, and then restocked. Practices today lean more towards sustainability.