A multicohort stock production model

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

An age structured production model of multicohort fish population dynamics based on the mean metabolic state of individuals and the average abundance of year-classes is proposed. The model allows variations in life stage basal metabolic rates by parameterizing their effects on total population abundance through a mortality function which itself depends upon an individual's status relative to an optimal metabolic state. The metabolic equations are derived in terms of age-specific individual weight. The interaction of individual status and intraspecific competition is allowed by coupling the metabolic equations for growth to those for population abundance. This coupling yields a second-order nonlinear equation in abundance or biomass. In model simulations, (1) increased numbers of cohorts decreased the stability of population biomass, (2) numerically 'strong' year- classes damped and sometimes caused collapse of proximal age-classes, (3) exploitation reduced competitive interactions and increased model stability, and (4) increases in natural mortality introduced greater recruitment variability. The transitional and steady state behaviors of the multicohort model are explored and compared to traditional fishery management models for a small pelagic species, northern anchovy Engraulis mordax.

Original languageEnglish
Pages (from-to)343-363
Number of pages21
JournalTransactions of the American Fisheries Society
Volume125
Issue number3
StatePublished - Dec 1 1996

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basal metabolic rate
biomass
intraspecific competition
mortality
fisheries management
age structure
simulation models
fishery management
age class
population dynamics
fish
simulation
Engraulis mordax
rate
effect

ASJC Scopus subject areas

  • Aquatic Science
  • Earth and Planetary Sciences(all)
  • Environmental Science(all)

Cite this

A multicohort stock production model. / Ault, Jerald S; Olson, Donald.

In: Transactions of the American Fisheries Society, Vol. 125, No. 3, 01.12.1996, p. 343-363.

Research output: Contribution to journalArticle

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