Harvest (Aquaculture)

Harvest in aquaculture is the planned removal of market-sized fish from the production unit, from pre-harvest preparation through capture, slaughter, and chilling, and it is the single event that converts biomass into revenue, so its handling determines product quality and value. Best practice begins days beforehand: feed is withdrawn for 1-3 days (or longer where off-flavour depuration is needed) to empty the gut and reduce oxygen demand and ammonia during crowding; licensed harvest plans schedule pumping, grading, and transport around temperature and weather. Crowding and netting stress fish, raising cortisol and depleting muscle energy reserves, so crowding duration is minimised and fish are stunned immediately, either percussively or electrically, followed by rapid bleeding in ice water. Core quality parameters set at harvest are freshness, flesh temperature reaching 0-4 °C within hours, and the absence of stress-related defects such as gaping, haematomas, or pale gills, which show up in fillets days later. Logistics are planned to the hour because delayed slaughter of stressed fish produces soft, watery flesh. Partial harvests to thin biomass before final harvest improve the growth of remaining fish, and accurate harvest counts and weights close the production cycle, feeding back real FCR and SGR data for the next cohort.