Title: A spatial model for fishery age-selection at the population level
Authors: SAMPSON DAVIDSCOTT ROBERT
Citation: CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES vol. 68 p. 1077–1086
Publisher: NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS
Publication Year: 2011
JRC N°: JRC58969
ISSN: 0706-652X
URI: http://www.nrcresearchpress.com/doi/pdf/10.1139/f2011-044
http://publications.jrc.ec.europa.eu/repository/handle/JRC58969
DOI: 10.1139/F2011-044
Type: Articles in Journals
Abstract: Different age-classes do not generally experience the same rates of fishing mortality. The processes that result in age- (or length-) selection operate at several scales. At the broadest 38 scale population-selection measures the age-specific probability of capture, whilst at the finest scale contact-selection describes the vulnerability of fish that encounter the fishing gear. Population-selectivity is the process most relevant to fish population dynamics and stock assessment but it has received far less attention than processes operating at gear specific scales. Despite wide recognition of the diverse shapes possible for population selectivity, the processes determining these shapes are poorly understood. This paper develops a reasonably simple model of population-selectivity from a set of survival equations, coupled to allow movement between subpopulations, and explores the conditions necessary to produce different shaped population-selection curves. Important factors influencing the population-selectivity model are the gear-specific selection characteristics of the fleets, their effort levels relative to one another, the spatial distribution of fishing mortality and the movement of fish between subpopulations. The model can generate quite complicated curves and has surprising properties. For example, even though the same asymptotic gear-selectivity applies in all subpopulations the overall population-selectivity will be dome-shaped unless fishing mortality is uniform across all subpopulations.
JRC Institute:Institute for the Protection and Security of the Citizen

Files in This Item:
There are no files associated with this item.


Items in repository are protected by copyright, with all rights reserved, unless otherwise indicated.