Fish hatchery

fish hatchery is a place for artificial breeding, hatching, and rearing through the early life stages of animals-finfish and shellfish in particular. [1] Hatcheries produce larval and juvenile fish , shellfish , and crustaceans , primarily to support the aquaculture industry, where they are transferred to on-growing systems, such as fish farms, to reach harvest size. Some species That Commonly are raised in hatcheries include Pacific oysters , shrimp , Indian prawns , salmon , tilapia and scallops. The value of global aquaculture production is estimated to be US $ 98.4 billion in 2008 with China significantly dominating the market; However, the value of aquaculture hatchery and nursery production has yet to be estimated. [2] Additional hatchery production for small-scale domestic uses, which is particularly prevalent in South-East Asia or for conservation programs, has also yet to be quantified. [2] [3]

There is much interest in supplementing the exploitation of fish by releasing juveniles that can be caught and nursed before transplanting, or produced solely within a hatchery. [4]Culture of finfish larvae has been extensively used in the United States in stock enhancement efforts to replenish natural populations. [5] The US Fish and Wildlife Service has established a National Fish Hatchery System to support the conservation of native fish species. [6]

Purpose

Assynt Salmon hatchery, near Inchnadamph in the Scottish Highlands.

Hatcheries produce larval and juvenile fish and shellfish for aquaculture where they are ‘on-grown’ to reach harvest size. Hatchery production confers three main benefits to the industry;
1. Out of season production
is an important market requirement. [7] Broodstock conditioning can extend the natural spawning season and thus the supply of juveniles to farms. [7] [8] Supply can be further guaranteed by hatching in the opposite hemisphere ie with opposite seasons. [9]
2. Genetic improvement
Genetic modification is carried out in certain hatcheries to improve the quality and yield of farmed species. Artificial fertilization facilitates selective breeding programs that improve survival rate, survival resistance, color, increased fecundity and / or lower age of maturation. [7] Genetic improvement can be mediated by selective breeding , via hybridization , or other genetic manipulationtechniques.
3. Reduce dependence on wild-caught juveniles
In 2008 aquaculture accounted for 46% of total food fish supply, around 115 million tonnes. [2]Although wild caught juveniles are still used in the industry, it concerns the sustainability of juvenile extraction, and the variable timing and magnitude of natural spawning events, make hatchery production an attractive alternative to supporting the growing demands of aquaculture. [2] [7] [10]

Production steps

Manually stripping eggs
Juvenile salmon towards the end of their stay in a hatchery

Broodstock

Broodstock conditioning is the process of bringing about the development of gonads. Broodstock can be extended beyond natural spawning periods, or for the production of species with different environmental conditions. [7] [8] Some of the hatcheries collect wild adults and then bring them into the market for a permanent breeding stock. [5] [10] Optimizing the conditions for light, temperature, salinity, flow rate and food availability. [11]Another important aspect of broodstock conditioning is ensuring the production of high quality eggs to improve growth and survival of the population. Egg quality is often determined by the nutritional condition of the mother. [12] [13] High levels of lipid reserve in larval survival rates. [13] [14]

Spawning

Natural spawning can occur in the presence of spider mites. [5] Some
stripping methods : For shellfish, gonads are generally removed and gametes are extracted or washed free. [7] Fish can be manually stripped of eggs and sperm by stroking the anesthetized fish under the pectoral fins towards the anus causing gametes to freely flow out.
Environmental manipulation : Thermal shock, where cool water is alternated with warm water in flow-through tanks can induce spawning. [7] [10]Alternatively, if environmental cues that stimulate natural spawning are known, [10] Many individuals may be induced to spawn this way, however, this increases the likelihood of uncontrolled fertilization. [7]
Chemical injection : A number of chemicals that can be used to induce sputum with various hormones being the most commonly used. [10]

Fertilization

Prior to fertilization , eggs may be gently washed away and contaminated. Promoting cross-fertilization between a large number of individuals is necessary to retain genetic diversity in hatchery produced. These two types of eggs are kept separate from one another, and they are kept separate from one another to a greater or lesser extent and to a greater or lesser extent. [7] [10]

Larvae

Rearing larvae through the early life trainees is usually associated with hatching for fish culture while it is common for shellfish nurseries to exist separately. [1] Nursery culture of larvae to rear juveniles can be performed in a variety of different systems which may be entirely land-based, or may be transferred to sea-based rearing systems. which reduce the need to supply feed. [7]Juvenile survival is dependent on very high quality water conditions. [7] [10]Feeding is an important component of the rearing process. Nurseries are most likely to grow on the basis of survival, growth, yield and juvenile quality. Nutritional requirements are specific and also vary with larval stage. 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 . [5] The production of live feeds is one of the biggest costs for hatchery facilities as it is a labor-intensive process. [15]The development of artificial feeds is aimed at reducing the cost of nutrition and increasing the availability of these products. [16]

Settlement of shellfish

The hatchery production of shellfish also involves a critical settling phase where the free-swimming larvae settle out of the water onto a substrate and undergoes metamorphosis if suitable conditions are found. Once metamorphosis has taken place in the world, it is this phase which is then transported to on-growing facilities. Settlement behavior includes a range of conditions including water flow, temperature, and the presence of chemical cues indicating the presence of adults, or a food source. [7] [17 [17] [7] [17] [7] [17] Hatchery means substituting artificial substrates to allow for easy handling and transportation with minimal mortality. [7][18]

Hatchery design

Multi-Species Fish and Invertebrate Breeding and Hatchery, (Oceanographic Marine Laboratory in Lucap, Alaminos, Pangasinan , Philippines , RMaTDeC, 2011).

Hatchery designs are highly flexible and are tailored to the requirements of the site, species produced, geographic location, funding and personal preferences. [7] Many hatchery facilities are small in size and larger in size, while others may produce juveniles only for sale. Very small-scale hatcheries are often used in subsistence farming to supply families or communities particularly in south-east Asia. [3] A small-scale hatchery unit consists of larval rearing tanks, filters, live food production tanks and a flow through water supply. [3]A generalized commercial scale hatchery would be a broodstock holding and spawning area, feed culture facility, larval culture area, juvenile culture area, pump facilities, laboratory, quarantine area, and offices and bathrooms. [8]

Expense

Labor production is more than 50% of total costs. [19] Hatcheries are a business and thus economic viability and scale of production are vital considerations. [7] [15] The cost of production for stock-enhancement programs is further complicated by the difficulty of assessing the benefits of wild populations from restocking activities. [4]

Issues

Genetic

Hatchery facilities present three main problems in the field of genetics. The first is that maintenance of a small number of broodstock can cause inbreeding and potentially lead to inbreeding depression thus affecting the success of the facility. Secondly, hatchery reared juveniles, even from a fairly large broodstock, can have greatly reduced genetic diversity compared to wild populations (the situation is comparable to the founder effect ). Such fish that escape from farms may be released for restocking purposes may adversely affect wild population genetics and viability. [4] This is of particular concern where escaped fish have been actively or genetically modified. [20]The third key issue is that genetic modification of food items is highly desirable for many people. See [Genetically modified food controversies]

Fish farms

Other arguments that surround fish farms such as the supplementation of the food of the species, the prevalence of disease, fish welfare issues and potential effects on the environment are also issues for hatchery facilities. For more information see: Aquaculture , Mariculture , Fish farming

See also

  • List of harvested aquatic animals by weight
  • Caledonia Fish Hatchery
  • Mount Whitney Fish Hatchery
  • Raceway (aquaculture)

References

  1. ^ Jump up to:b Crespi V., Coche A. (2008) Food and Agriculture Organization of the United Nations (FAO) Glossary of Aquaculture [1]
  2. ^ Jump up to:d FAO (2010) State of World Fisheries and Aquaculture
  3. ^ Jump up to:c Sim, SY, MA Rimmer, JD Toledo, K. Sugama, I. Rumengan, K. Williams and MJ Phillips (2005). A guide to small-scale marine finfish hatchery technology. Australian Center for International Agricultural Research 2005-01 [2]
  4. ^ Jump up to:c Munro JL, Bell JD (1997) Enhancement of marine fisheries resources: Reviews in Fisheries Science 5 (2): 185-222
  5. ^ Jump up to:d Lee CS, Ostrowski AC (2001) Current status of marine finfish larval rearing in the United States Aquaculture 200: 89-109
  6. Jump up^ United States Fish and Wildlife Service: Fisheries and Habitat Conservation (2009) National Fish Hatchery Systemhttp://www.fws.gov/fisheries/nfhs/accessed: 22/09/11
  7. ^ Jump up to:o Helm, MM, Bourne, N. (2004) Hatchery Culture of bivalves: a practical manual. FAO, Rome, 201pp. [3]
  8. ^ Jump up to:c Moretti A., Fernandex-Criado MP, Vetillart R. (2005) Manual on Hatchery Production of Seabass and Gilthead Seabream Volume 2 FAO, Rome, 163pp. [4]
  9. Jump up^ Cooper D. (2007) Perch eggs sent to Ireland NZ Aquaculture 20: 11
  10. ^ Jump up to:g Kungvankij P., LB Tiro Jr. Pudadera BJ Jr., Potesta IO (1985) Training Manual: Biology and Culture of Sea Bass (Lates calcarifer) FAO, Rome, 75pp. [5]
  11. Jump up^ Demoulin F. (1999) Guidelines for broodstock and hatchery management; Support for technical services FAO, Rome, 59pp. [6]
  12. Jump up^ Wilson, JA, Chaparro, OR, Thompson, RJ (1996). The importance of broodstock nutrition on the viability of larvae and spat in the Chilean oyster Ostrea chilensis. Aquaculture 139, 63-75
  13. ^ Jump up to:b Utting, SD, Millican, PF (1997). Techniques for the hatchery conditioning of bivalve broodstocks and the subsequent effect of egg quality and larval viability. Aquaculture 155, 45-54
  14. Jump up^ Powell, EN, Bochenek, EA, Klinck, JM, Hofmann, EE (2002). Influence of food quality and growth on Crassostrea gigas larvae: a modeling approach. Aquaculture 210, 89-117
  15. ^ Jump up to:b Kam, LE, P. Leung, AC Ostrowski and A. Molnar (2002). Size of a Pacific Threadfin Polydactylus sexfilis Hatchery in Hawaii. Journal of the World Aquaculture Society 33 (4): 410-424
  16. Jump up^ Cahu C.,’ZamboninoInfante J. (2001) Substitution of live food by formulated diets in marine fish larvae Aquaculture 200 (1-2): 161-180
  17. Jump up^ Zhao, B., Zhang, S., Qian, P.-Y. (2003). Larval settlement of the silver or gold pearl oyster Pinctada maxima (Jameson) in response to natural biofilms and chemical cues. Aquaculture 220, 883-901
  18. Jump up^ Taylor, JJ, Southgate, PC, Pink, RA (1998). Assessment of artificial substrates for the collection of hatchery-reared silver-lip pearl oyster (Pinctada maxima, Jameson) spat. Aquaculture 162, 219-230
  19. Jump up^ Lee, CS, PS and MS Leung Su (1997) Bioeconomic assessment of different systems for milkfish fry Production (Chanoschanos). Aquaculture 155 (1-4): 367-376.
  20. Jump up^ Huntingford FA (2004) Implications of domestic and rearing conditions for the behavior of cultured fishes Journal of Fish Biology 65 (SUPPL A): 122-142

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