Fish stocks are subpopulations of a particular species of fish, for which intrinsic parameters (growth, recruitment, mortality and fishing mortality) are the only significant factors in determining population dynamics, while extrinsic factors (immigration and emigration) are considered to be insignificant. For the fishing industry and the practice of fishing see Fishing. Fish farming is the principal form of Aquaculture, while other methods may fall under Mariculture. In Aquaculture, the broodstock is a group of sexually mature individuals of a cultured species that is kept separate for breeding purposes Fish hatcheries are used to cultivate and breed a large number of fish in an enclosed environment Fish Hatcheries typically involve a lot of manual labour Fish stocking is the practice of raising Fish in a hatchery and releasing them into a River, Lake, or the Ocean to supplement existing Salmon is the common name for several species of Fish of the family Salmonidae. Catfish are easy to farm in warm climates leading to inexpensive and safe food at local grocers See also Tilapia Because of their large size rapid growth and palatability a number of Tilapiine cichlids are at the focus of major Aquaculture efforts This article is about the farming of freshwater prawns For the farming of marine (saltwater shrimps see Shrimp farming A freshwater prawn farm This article is about the farming of marine (saltwater shrimp Oyster farming is an Aquaculture (or Mariculture) practice in which Oysters are raised for human consumption Tailwater refers to a type of Trout Fishery. Tailwater fisheries are created at the outflow from large Dams where the size of the reservoir creates Hirudiculture is the culture or Farming, of Leeches in both natural and artificial environments The National Fish Hatchery System was established by the US Congress in 1871 through the creation of a U A sea louse (plural sea lice) is a name given to any oceanic stinging Larvae, which includes many juvenile Cnidarians (notably Linuche unguiculata Infectious Hypodermal and Hematopoietic Necrosis (IHHN is a viral disease of Penaeid Shrimp that causes mass mortality (up to 90% among the Western blue The controversy Taura syndrome (TS was first described in Ecuador during the summer of 1992 White spot syndrome (WSS is a viral infection of Penaeid Shrimp. Yellowhead disease (YHD is a viral infection of Shrimp and Prawn, in particular of the giant tiger prawn ( Penaeus monodon) one of Aquaculture is the farming of freshwater and saltwater organisms including Molluscs Crustaceans and aquatic plants For the computer security term see Phishing. Fishing is the activity of catching Fish. In Biology a population is the collection of inter-breeding organisms of a particular Species; in Sociology In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. Fish are aquatic Vertebrate animals that are typically ectothermic (previously Cold-blooded) covered with scales, and equipped with two Population dynamics is the study of marginal and long-term changes in the numbers individual weights and age composition of individuals in one or several Populations and
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The stock concept
All species have geographic limits to their distribution, which are determined by their tolerance to environmental conditions, and their ability to compete successfully with other species. See also Nature The natural environment, commonly referred to simply as the environment, is a terminology that is comprised of all living and Competition is a rivalry between individuals groups nations or animals for territory or resources In marine environments this may be less evident than on land because there are fewer topographical boundaries, however, discontinuities still exist, produced for example by mesoscale and sub-mesoscale circulations that minimize long-distance dispersal of fish larvae . An ocean (from Greek, ''Okeanos'' (Oceanus) is a major body of saline water, and a principal component of the Hydrosphere. Topography ( topo-, "place" and graphia, "writing" is the study of Earth 's Surface features or those of Planets
For fishes, it is rare for an individual to reproduce randomly with all other individuals of that species within its biological range. There is a tendency to form a structured series of discrete populations which have a degree of reproductive isolation from each other in space, in time, or in both. This isolation is reflected in the development between sub-populations of genetic differences, morphological variations and exposure to different chemical regimes and parasitic species. History See also History of genetics The existence of genes was first suggested by Gregor Mendel (1822-1884 who in the 1860s studied inheritance The term morphology in Biology refers to the outward appearance ( Shape, Structure, Colour, Pattern) of an Organism A chemical substance is a Material with a definite chemical composition. Parasitism is a type of symbiotic relationship between Organisms of different Species. Sub-populations also respond to fishing in such a way that fishing on one population appears to have no effect on the population dynamics of a neighbouring population.
The currently accepted definition of a stock in fisheries science, is that of Begg et al. (1999), “…[a “stock”] describes characteristics of semi-discrete groups of fish with some definable attributes which are of interest to fishery managers. ”.
Stock identification is a field of fisheries science which aims to identify these subpopulations, based on a number of techniques. Fisheries science is the academic discipline of managing and understanding Fisheries.
References
- Begg, G. A. , Friedland, K. D. & Pearce, J. B. (1999) Stock identification and its role in stock assessment and fisheries management: an overview. Fisheries Research 43:1-8
- Booke, H. E. (1999) The stock concept revisited: perspectives on its history in fisheries. Fisheries Research 43:9-11
- S. X. Cadrin, K. D. Friedland, J. R. Waldman. (2004) Stock Identification Methods : Applications in Fishery Science. ISBN 0-12-154351-X
See also
External links
- Identification of stocks of horse macekerel, Trachurus trachurus
- Identification of stocks of herring, Clupea harengus
- FAO Fisheries Department and its SOFIA report addressing fish stocks
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