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. Map of populations by country Taiwanese people waiting for the Taipei Rapid Transit System in Taipei, Republic of China(Taiwan). ... In biology, a species is one of the basic units of biodiversity. ... A giant grouper at the Georgia Aquarium Fish are aquatic vertebrates that are typically cold-blooded; covered with scales, and equipped with two sets of paired fins and several unpaired fins. ... 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 biological and environmental processes influencing those changes. ...

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. 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 . It has been suggested that toleration be merged into this article or section. ... This article does not adequately cite its references or sources. ... Competition is the act of striving against another force for the purpose of achieving dominance or attaining a reward or goal, or out of a biological imperative such as survival. ... The worlds oceans as seen from the South Pacific Ocean, before the definition of the Southern Ocean in 2000 For other uses, see Ocean (disambiguation). ... It has been suggested that Geomorphometry be merged into this article or section. ...

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. 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. Look up discrete in Wiktionary, the free dictionary. ... For other meanings of this term, see gene (disambiguation). ... The term morphology in biology refers to the outward appearance (shape, structure, colour, pattern) of an organism or taxon and its component parts. ... A chemical substance is any material substance used in or obtained by a process in chemistry: A chemical compound is a substance consisting of two or more chemical elements that are chemically combined in fixed proportions. ... A parasite is an organism that spends a significant portion of its life in or on the living tissue of a host organism and which causes harm to the host without immediately killing it. ...

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. A fishery (plural: fisheries) is an organized effort by humans to catch fish or other aquatic species, an activity known as fishing. ...

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

• Overfishing

× The Traffic Light colour convention, showing the concept of Harvest Control Rule (HCR), specifying when a rebuilding plan is mandatory in terms of precautionary and limit reference points for spawning biomass and fishing mortality rate. ...

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
• State of World Fish Stocks – A summary for non-specialists of the above FAO report by GreenFacts