Hatchery
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- For the third season episode of Star Trek: Enterprise, see "Hatchery (Star Trek: Enterprise)".
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A hatchery is a facility where eggs are hatched under artificial conditions, especially those of fish or poultry. It may be used for ex-situ conservation purposes, i.e. to breed rare or endangered species under controlled conditions; alternatively, it may be for economic reasons (i.e. to enhance food supplies or fishery resources).
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[edit] Fish hatcheries
[edit] Function
Fish Hatcheries are used to cultivate and breed a large number of fish in an enclosed environment, typically involving manual labor. A hatchery worker will take a female fish, release her eggs (stripping), and then externally add the male fish's sperm (milt), mix them and allow them to fertilize and incubate undisturbed, where there is less risk of disease or predation. They can immediately dispose of any unfertilized eggs. What happens next depends on the purpose of the Hatchery. Fish farms use Hatcheries to cultivate fish to sell for food, or ornamental purposes, eliminating the need to find the fish in the wild and even providing some species outside of their natural season. They raise the fish until they are ready to be eaten or sold to aquarium stores. Other Hatcheries release the juvenile fish into a river, lake or the ocean to support commercial, tribal, or recreational fishing or to supplement the natural numbers of threatened or endangered species, a practice known as fish stocking. Some fish Hatcheries are used to mitigate the effects of development, such as construction of a dam, hydroelectric plant or water diversion. In the United States and Canada, these hatcheries usually raise anadromous fish that are unable to migrate due to the obstruction, particularly salmon and steelhead. In 1889 a cod fish hatchery was erected on an island belonging to Newfoundland and Labrador. It was the largest hatchery in the world at that time and the first in North America. The ornamental fish industry uses fish hatcheries to produce fish for the aquarium fish trade, this has helped to limit the over harvesting of native fish populations both in fresh and salt water ecosystems.
[edit] Criticisms
Originally devised to mitigate for fish production lost through development and supply the demand for fishing from an expanding human population, fish hatcheries have been causing problems by producing poor quality or genetically inferior fish. Several researchers have raised concerns about hatchery fish potentially breeding with wild fish. Hatchery fish may in some cases compete with wild fish. [1] There is lively debate among the scientific community regarding the risks and benefits of hatchery programs. Proving negative (or positive) effects of hatchery programs on wild fish is challenging due to numerous other environmental and anthropogenic factors that simultaneously affect fish. In the United States and Canada, there have been several salmon and steelhead hatchery reform projects intended to reduce the possibility of negative impacts from hatchery programs. Most salmon and steelhead hatcheries are managed better and follow up to date management practices to ensure any risks are minimized.
[edit] Poultry hatcheries
Poultry hatcheries produce a majority of the birds consumed in the developed world including chickens, turkeys, ducks and some other minor bird species that are consumed. It is a multi billion dollar industry with highly regimented production systems used to maximize bird size verse feed consumed. Birds are produced and maintained under high density which makes production and harvesting more economical but can also generate problems such as the spread of pathogens, which can move very quickly through the population when animal densities are high. Poultry hatcheries generally start with artificially inseminated birds that lay eggs, the eggs are cleaned and shells are checked for soundness before putting them in the incubators. The incubators control temperature and humidity and turn the eggs until they hatch. Generally large numbers of eggs are produced at one time so that the resulting birds are uniform in size and can be harvested at the same time. Once the eggs hatch and the chicks are a few days old they are often beak-trimmed and or toe-clipped, this involves the removal of half of the top beak and the clipping of the toe ends. This is done to prevent the birds from harming each other while they are living in close proximity to each other. After these procedures they are moved to enclosed buildings to be raised until harvest.
[edit] See also
[edit] References
- ^ Genetics and the Extinction of Species, Laura F. Landweber and Andrew P. Dobson eds., Princeton University Press (1999)
[edit] External links
- Hatcheries and the Protection of Wild Salmon
- University of Washington Libraries Digital Collections -- Digital Collections -- Fish Hatcheries An ongoing digital collection of images related to fish hatcheries.
- [1] - Links to hatchery reform projectsca:Eclosionadora
