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Modelling length-at-age variability under irreversible growth

Gurney, William S. C.; Tyldesley, Graham; Wood, Simon N.; Bacon, Philip J.; Heath, Michael R.; Youngson, Alan; Ibbotson, Anton. 2007 Modelling length-at-age variability under irreversible growth. Canadian Journal of Fisheries and Aquatic Sciences, 64 (4). 638-653. 10.1139/F07-039

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Abstract/Summary

In this paper, we describe a discrete-time formalism for describing the dynamics of the size-at-age distribution of a cohort of individuals exhibiting irreversible von Bertalanffy growth in a statistically uniform random environment. This formalism yields a highly efficient numerical implementation, which is particularly suited to automatic optimization. In the special case where mortality is sufficiently size-independent not to vary substantially across the bulk of the size distribution at any given age, we can further increase this efficiency by deriving compact update rules for the mean and coefficient of variation of size-at-age. In this case, we also demonstrate that the depensatory effect of random growth variability and the compensatory effect of deterministic von Bertalanffy growth balance to yield an attracting (initial condition independent) trajectory of mean length and length coefficient of variation against age. We demonstrate the applicability and extensibility of this formalism by two exemplary applications - juvenile salmonids and demersal cod.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1139/F07-039
Programmes: CEH Programmes pre-2009 publications > Water
CEH Sections: Acreman
ISSN: 0706-652X
Additional Information. Not used in RCUK Gateway to Research.: NRC Research Press Copyright policy: Once an author's paper is accepted for publication, the author transfers copyright to the National Research Council Canada. (For papers authored by public servants in Commonwealth countries, including Canada, Crown copyright cannot be transferred, and a license to publish is granted instead. For papers authored by US federal government employees, no copyright exists, and a publishing agreement is signed in lieu of copyright transfer.) As the holder of copyright on all original material published by NRC Research Press, NRC exercises the right to grant permission to copy or republish articles or portions thereof, provided that the source of such material is fully acknowledged. NRC reserves the right to charge for all forms of copying or publishing, such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale. http://pubs.nrc-cnrc.gc.ca/eng/policy/index.html#copyright
NORA Subject Terms: Zoology
Biology and Microbiology
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Date made live: 24 Jan 2008 15:23
URI: http://nora.nerc.ac.uk/id/eprint/2182

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