Fish hatchery

Some species that are commonly raised in hatcheries include Pacific oysters, shrimp, Indian prawns, salmon, tilapia and scallops.

[2][3] There is much interest in supplementing exploited stocks of fish by releasing juveniles that may be wild caught and reared in nurseries before transplanting, or produced solely within a hatchery.

[4] Culture of finfish larvae has been utilised extensively in the United States in stock enhancement efforts to replenish natural populations.

[6] Hatcheries produce larval and juvenile fish and shellfish for transferral to aquaculture facilities where they are ‘on-grown’ to reach harvest size.

Artificial fertilisation facilitates selective breeding programs which aim to improve production characteristics such as growth rate, disease resistance, survival, colour, increased fecundity and/or lower age of maturation.

Reduce dependence on wild-caught juveniles In 2008 aquaculture accounted for 46% of total food fish supply, around 115 million tonnes.

[5] Some of the more common methods are: Manual stripping: For shellfish, gonads are generally removed and gametes are extracted or washed free.

[7][10] Alternatively, if environmental cues that stimulate natural spawning are known, these can be mimicked in the tank e.g. changing salinity to simulate migratory behaviour.

Carnivorous fish are commonly fed with live prey; rotifers are usually offered to early larvae due to their small size, progressing to larger Artemia nauplii or zooplankton.

[7][17] Hatchery facilities therefore need to understand these cues to induce settlement and also be able to substitute artificial substrates to allow for easy handling and transportation with minimal mortality.

[7][18] Hatchery designs are highly flexible and are tailored to the requirements of site, species produced, geographic location, funding and personal preferences.

[7] Many hatchery facilities are small and coupled to larger on-growing operations, whilst others may produce juveniles solely for sale.

Such fish that escape from farms or are released for restocking purposes may adversely affect wild population genetics and viability.