France, R., Holmes, J., & Lynch, A. (1991). Use of size-frequency data to estimate the age composition of crayfish populations (Vol. 48).
Zusammenfassung: Age-classes in crayfish populations can be determined from size-frequency data provided 4 tents are adhered to only crayfish collected from areas of rock substrate are used; trapping are excluded; species do not have longevities exceeding about 4 yr; and most importantly, sample sizes are greater than about 200. Studies that have failed to follow these guidelines have met with limited success in dissecting mixed frequency distributions. Further, 3 validation procedures must be undertaken: temporal replication within molting events to measure the precision of both data collection and size-frequency analysis; corroboration with known-age crayfish from either field recaptures or laboratory molt increments; and concordance with independent analysis of the mean size at onset of sexual maturity. When these checks support the size-frequency results, population age composition and analyses of rates of growth or mortality can be considered reliable.
Schlüsselwörter: Krebs, lÄngenfrequenz, methode, statistik, population
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Groeneveld, T. (1991). C++ für Aufsteiger.
Schlüsselwörter: Turbo-c, oop
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Murphy, B. R., Willis, D. W., & Springer, T. A. (1991). The Relative Weight Index in Fisheries Management: Status and Needs (Vol. 16).
Schlüsselwörter: Fischerei, statistik, wachstum, modell
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Hiramatsu, K. (1991). Possible Biases in the VPA Estimates of Population Sizes of the Plus Group (Vol. 39).
Zusammenfassung: Biases in estimating population sizes of the plus group are examined for bluefin tuna (Thunnus ) and swordfish (Xiphias gladius ). It is shown that the VPA estimates used in the 1990 ICCAT assessment are sensitive to the systematic ageing errors. The biases in the estimates of population sizes of the plus group might increase exponentially with tracing back to the earlier year.
Schlüsselwörter: Fischerei, statistik, vpa, population, methode, theorie, mathematik
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Lepetit, M., Loranchet, S., Gillet, P., & Marion, J. M. (1991). Un Logiciel De Traitement Des Histogrammes De Structure De Population Par La M+Thode Des Differences Logarithmiques De Bhattachary (Vol. 41).
Zusammenfassung: The software “BHATTA”, achieved in Turbo Pascal on IBM PC makes possible histogram analysis for population structure. The base of the study is an analysis of population dynamics from histograms of size frequency. The program “BHATTA”, made from the method of logarithmic differences of Bhattacharya, cuts the histograms in order to display Gaussian components and to estimate the parameters: number (size of sample), mean and standard deviation for each generation or cohort to determine growth curves for each cohort.
Schlüsselwörter: Population, statistik, programm, pascal, lÄngenfrequenz, methode
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Yamagishi, H., & Ishioka, K. (1991). Silumation Study on the Growth Variation of Fish with Special Reference to the Mortality by Cannibalism.
Zusammenfassung: In respect to the higher initial mortality in fish by cannibalism, computer simulation of individual growth variation was made in terms of coefficient of variation(CV) and skewness(sk) of frequency distribution. CV of the cannibalistic groups changed similarly to the control groups, but converged on smaller values than the asymptotic CV of the control groups. Sk of the cannibalistic groups finally converged on similar values to those of the control groups after irregular changes in positive values except N-N correspondent type.
Schlüsselwörter: Wachstum, mortalitÄt, simulation, methode, theorie, statistik
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Nunney, L. (1991). The influence of age structure and fecundity on effective population size (Vol. 1991).
Schlüsselwörter: Population, Biologie, Theorie, Poisson
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Waterstraat, A. (1991). Einfluß von Regenbogenintensivanlagen auf Fließgewässerichthyozönosen am Beispiel von Nebel und Gehlsbach (Vol. 29).
Schlüsselwörter: Fisch, Regenbogenforellen, Salmo gairdneri, Aquakultur, Schaden, Einfluss
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Groeneveld, T. (1991). Binäre Beine – Sicherer Stand bei Suchalgorithmen in C++.
Schlüsselwörter: Turbo-c, oop, sortieren, methode, Grundlage
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Schirmer, M. (1991). Verbreitung der Fische im Land Bremen (Vol. 41).
Schlüsselwörter: Fisch, Vorkommen, Bremen, Kartierung
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