Synopsis
Numbers and lengths of young crappie were measured over a 20-week period in a Tennessee River reservoir. From these data, the average length at the swimming interval and growth rate were computed. A partial differential equation model was formulated for changes in length distribution through time. The equation was solved analytically and this solution used to predict the numbers by length class through time, given an initial known recruitment or swim-up rate. The simulated numbers agreed in considerable detail with the observations, indicating that the model accurately reflected the basic population mechanics involved. This suggests the model can be used to predict impacts to the fish population of size-dependent mortality caused by man, such as impingement on power plant intake screens.
References cited
Hackney, P. A. & J. C. Webb. 1978. A method for determining growth and mortality rates of ichthyoplankton. pp. 115–124. In: L. D. Jensen (ed.) Proc. Fourth National Workshop on Entrainment and Impingement, Ecological Analysts, Inc., Melville, New York.
Oster, G. & Y. Takahashi. 1974. Models for age specific interactions in a periodic environment. Ecol. Monog. 44: 483–501.
Rotenberg, M. 1975. Equilibrium and stability in populations whose interactions are age-specific. J. Theor. Biol. 54: 207–224.
Sinko, J. W. & W. Streifer. 1967. A new model for age-size structure for a population. Ecology 48: 910–918.
Sinko, J. W. & W. Streifer. 1971. A model for populations reproducing by fission. Ecology 52: 331–335.
Tennessee Valley Authority. 1976. Yellow Creek Nuclear Plants. Units 1 and 2. Environmental Report, Vol. 1, 2, and 3. Docket Nos. STN 50-556, STN 50-567.
Van Sickle, J. 1977. Analysis of a distributed-parameter population model based on physiological age. J. Theor. Biol. 64: 571–586.
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DeAnglis, D.L., Hackney, P.A. & Webb, J.C. A partial differential equation model of changing sizes and numbers in a cohort of juvenile fish. Environ Biol Fish 5, 261–266 (1980). https://doi.org/10.1007/BF00005361
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DOI: https://doi.org/10.1007/BF00005361