Quick Definition
A facility where fish eggs are artificially incubated and larvae are reared through early life stages for aquaculture production or wild stock supplementation.
📖 Full Definition
A fish hatchery is a controlled facility for the artificial propagation of fish. Key functions include: spawning induction, egg collection and fertilisation, egg incubation (in specialised incubation systems with controlled flow, temperature, and oxygen), first-feeding larval rearing, and juvenile (fry/fingerling) production. Hatcheries serve two main purposes: commercial aquaculture production (seed supply for grow-out farms) and wild stock enhancement (stocking rivers and lakes with hatchery-reared juveniles to supplement depleted wild populations). The distinction between hatchery and wild fish is critical in salmonid fisheries — hatchery fish have lower fitness and may harm wild fish through competition, interbreeding, and disease transmission.