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 emmigration) are considered to be insignificant. In the most common sense of the word, a population is the collection of people—or organisms of a particular species—living in a given geographic area. ... In biology, a species is a kind of organism. ... Atlantic herring, Clupea harengus, the most abundant fish species in the world. ... 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 Tolerance is a social, cultural and religious term applied to the collective and individual practice of not persecuting those who may believe, behave or act in ways of which one may not approve. ... Environment - Wikipedia /**/ @import /skins/monobook/IE50Fixes. ... Competition characterises a biochemical, ecologic, economic, political, or sporting activity whereby two or more individuals or groups strive antagonistically against one another for some reward. ... France Marines is the name of a commune in the département of Val dOise, France. ... Topography, a term in geography, has come to refer to the lay of the land, or the physiogeographic characteristics of land in terms of elevation, slope, and orientation. ...

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 regiemes 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 an neighbouring population. The word discrete comes from the Latin word discretus which means separate. ... This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ... Morphology is the following: In linguistics, morphology is the study of the structure of word forms. ... 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 lives in or on the living tissue of a host organism at the expense of that host. ...

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 012154351X

External Links

• Identification of stocks of horse macekerel, Trachurus trachurus (http://www.homsir.com)
• Identification of stocks of herring, Clupea harengus (http://www.clupea.net/westher)