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Labelle, M. (1994). A likelihood method for estimating Pacific salmon escapement based on fence counts and mark-recapture data (Vol. 51).
Zusammenfassung: Pacific salmon (Oncorhynchus spp.) escapements in natural streams are often determined by conducting fence counts in conjunction with mark-recapture operations. Typical field conditions are characterized by protracted floods, undetected immigration, variation in sampling rates, mortality during the census periods, small sample sizes, and few successive recaptures. Closed population models tend to overestimate escapement under such conditions, and traditional open population models cannot always be relied on due to the lack of sufficient data. A likelihood-based estimation method was specifically designed for such conditions. A distinguishing feature of this model is that individual recapture histories are not required for parameter estimation. The model is also structured to incorporate ancillary data in the estimation process to improve the precision and accuracy of the estimates. The model is described in detail, and suggestions are made to facilitate its application.
Schlüsselwörter: capt-recapt, methode, ML, modell, statistik, simulation
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McGarvey, R. (1994). An age-structured open-access fishery model (Vol. 51).
Zusammenfassung: A dynamic model for open-access fisheries is presented. In addition to density dependence in recruitment and fishing effort changing in proportion to the level of profit fishermen earn which characterizes previous open-access models, it incorporates full age structure for the fish stock, lognormal environmental recruitment variability, and gear selectivity. The predator-prey cycling solution of the original Schaefer dynamic model, and subsequent open-access models, persists for these model extensions. Density dependence in recruitment induces greater global stability. Environmental recruitment variability, common in marine populations, is destabilizing in the neighborhood of the open-access equilibrium. Approximating model steady states of effort and catch by the corresponding averages from data time series underlies a new algorithm of parameter evaluation, applied here to an open-access model of the Georges Bank sea scallop (Placopecten magellanicus) fishery.
Schlüsselwörter: modell, statistik, population, dynamik, algorithmus
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Kenchington, E. L., & Full, W. E. (1994). Fourier analysis of sea scallop (Placopecten magellanicus) shell in determining population structure (Vol. 51).
Zusammenfassung: Sea scallops (Placopecten magellanicus) were sampled from each of four scallop beds: the northeast peak of Georges Bank, Western Bank, St. Pierre Bank, and the Bay of Fundy near Digby, N.S. The outlines of scallop top shells were captured by video imagery using a semiautomated approach. Fourier shape descriptors were calculated and analyzed. Age and year-class effects were shown to be important factors influencing scallop shell shape. Allometric effects on Fourier harmonics also have a significant influence on shell shape in this species. Comparisons of Fourier harmonics between scallop beds separated by age and sampling year, and corrected for allometry, revealed significant differences in the majority of harmonic numbers.
Schlüsselwörter: population, fourier, statistik, methode, modell, wachstum, muscheln
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Weisberg, S. (1993). Using Hard-part Increment Data to Estimate Age and Environmental Effects. Can. J. Fish. Aquat. Sci., 50, 1229?1237.
Schlüsselwörter: Fisch, Alter, Methode, Altersbestimmung, Statistik, Mathematik, Schuppe, Knochenstruktur
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Richards, L. J., Schnute, J. T., Kronlund, A. R., & Beamish, R. J. (1801). Statistical Models for the Analysis of Ageing Error (Vol. 49).
Schlüsselwörter: Fischerei, population, alter, lÄngenfrequenz, statistik, methode, mathematik
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English, K. K., & Bocking, R. C. (1992). A Robust Procedure for Estimating Salmon Escapement based on the Area-Under-the-Curve Method (Vol. 49).
Schlüsselwörter: Fischerei, population, wachstum, methode, mathematik, theorie
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Ricker, W. E. (1992). Back-Calculation of Fish Lengths Based on Proportionality between Scale and Length Increments (Vol. 49).
Schlüsselwörter: Fischerei, statistik, methode, wachstum
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Richards, L. J., & Schnute, J. T. (1992). Statistical Models for Estimating CPUE from Catch and Effort Data (Vol. 49).
Schlüsselwörter: Fischerei, cpue, methode, statistik, modell
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Chen, Y., Jackson, D. A., & Harvey, H. H. (1992). A comparison of von Bertalanffy and polynomial functions in modelling fish growth data (Vol. 49).
Zusammenfassung: We compared the von Bertalanffy growth function (VBGF) and five polynormial functions (PF) in modelling fish growth for 16 populations comprising six species of freshwater fishes. Ranked results of the variance explained by each growth function indicated that VBGF described growth data better than three- and four-parameter polynomial functions. Log-transforming length and age greatly improved the goodness-of-fit of the three-parameter polynomial function. Statistical comparison of growth between populations or sexes was done using a general linear model for polynomial functions. The VBGF proved to be the best growth model for all 16 populations.
Schlüsselwörter: Fischerei, wachstum, methode, theorie, modell, statistik
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Talbot, A. J., & Doyle, R. W. (1992). Statistical Interrelation of Length, Growth, and Scale Circulus Spacing: Use of Ossification to Detect Nongrowing Fish (Vol. 49).
Schlüsselwörter: Fisch, wachstum, methode, statistik
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