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Autor Gascuel, D.   
  Titel [A simple adjustment method of age-length keys: Application to yellowfin tuna (Thunnus albacares) catches in the East Atlantic.] Typ Zeitschrift, Artikel
  Jahr 1994 Publikation Can. J. Fish. Aquat. Sci Kurztitel der Zeitschrift  
  Band 51 Ausgabe 3 Seiten 723-733  
  Schlüsselwörter fishery-management; stock-assessment; mathematical-models; growth-curves; biological-age; length-; Thunnus-albacares; AE,-East-Atlantic; tuna-fisheries  
  Zusammenfassung An adjustment method for age-length keys is presented that incorporates yearly variability in cohort abundances. The method is based on two models (one for growth and the other for standard deviations of length versus age) and involves an iterative algorithm. The algorithm rapidly converges to stable results that yield, under some conditions, maximum likelihood estimates. It is also used to estimate parameters of the length standard deviation model. The method is applied to yellowfin tuna (Thunnus albacares) catches in the eastern Atlantic from 1975 to 1989.  
  Adresse  
  Organisation Abschlussarbeit  
  Herausgeber Erscheinungsort Editor  
  Sprache Sprache der Zusammenfassung Originaltitel  
  Editor der Reihe Titel der Reihe Kurztitel der Reihe  
  Band der Reihe Ausgabe der Reihe Edition  
  ISSN ISBN Medium  
  Bereich Expedition Konferenz  
  Notizen (down) Leer Geprüft  
  Rufnummer Signatur 480  
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Autor Misra, R. K.   
  Titel Fitting and comparing several growth curves of the generalized von Bertalanffy type Typ Zeitschrift, Artikel
  Jahr 1986 Publikation Can. J. Fish. Aquat. Sci Kurztitel der Zeitschrift  
  Band 43 Ausgabe 8 Seiten 1656-1659  
  Schlüsselwörter mathematical-models; growth-curves; fishery-biology; evaluation-  
  Zusammenfassung The earlier version of the von Bertalanffy growth formula (VBGF) has three parameters and is a special case of the “generalized” VBGF which has four parameters. The special VBGF can easily lead to erroneous results whereas the large flexibility built into the generalized VBGF enables it to provide a biologically realistic fit to the data. The author presents a statistical method and a computer program in Fortran to fit the generalized VBGF to a sample (a sample comprises several age groups, with one or more observations in an age group) and to examine statistically the fit to a sample and to compare statistically these curves (and their individual parameters) fitted to several samples. An example is provided, which also compares the fit of the generalized VBGF with the special VBGF.  
  Adresse  
  Organisation Abschlussarbeit  
  Herausgeber Erscheinungsort Editor  
  Sprache Sprache der Zusammenfassung Originaltitel  
  Editor der Reihe Titel der Reihe Kurztitel der Reihe  
  Band der Reihe Ausgabe der Reihe Edition  
  ISSN ISBN Medium  
  Bereich Expedition Konferenz  
  Notizen (down) Leer Geprüft  
  Rufnummer Signatur 1116  
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Autor Fore, L. S.; Karr, J. R.; Conquest, L. L.   
  Titel Statistical properties of an index of biological integrity used to evaluate water resources Typ Zeitschrift, Artikel
  Jahr 1994 Publikation Can. J. Fish. Aquat. Sci Kurztitel der Zeitschrift  
  Band 51 Ausgabe 5 Seiten 1077-1087  
  Schlüsselwörter Umweltverschmutzung, Fisch, Elektrofischerei, Methode, Mathematik, Modell, Statistik, ANOVA  
  Zusammenfassung The authors determined the statistical properties of the index of biotic integrity (IBI) from electrofishing samples collected from Ohio streams. Although IBI is widely used to evaluate the condition of water resources by biologists and resource managers, expanding its role as a regulatory tool depends on statistical validation of its precision and power. We addressed these issues by constructing an additive variance model for IBI and testing the assumptions of that model directly with a bootstrap resampling algorithm and simulations using field data. Statistical properties of IBI supported the use of standard analysis techniques such as ANOVA for hypothesis testing. We determined with power analysis that IBI can distinguish between five and six nonoverlapping categories of biotic integrity based on a model that includes the effects of measurement error, variability of fish assemblages through time, and statistical interaction of location and time.  
  Adresse  
  Organisation Abschlussarbeit  
  Herausgeber Erscheinungsort Editor  
  Sprache Sprache der Zusammenfassung Originaltitel  
  Editor der Reihe Titel der Reihe Kurztitel der Reihe  
  Band der Reihe Ausgabe der Reihe Edition  
  ISSN ISBN Medium  
  Bereich Expedition Konferenz  
  Notizen (down) Inst. Environ. Stud., FM-12, Univ. Washington, Seattle, WA 98195, USA Geprüft  
  Rufnummer 526 Signatur 2325  
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Autor Adamicka, P.   
  Titel Biologie und Dynamik der Cottus-Population im Seebach Typ Zeitschrift, Artikel
  Jahr 1978 Publikation Jahresbericht Biologische Station Lunz Kurztitel der Zeitschrift  
  Band 1 Ausgabe Seiten 54-59  
  Schlüsselwörter Cottus gobio, Biologie, Fisch, Groppe  
  Zusammenfassung  
  Adresse  
  Organisation Abschlussarbeit  
  Herausgeber Erscheinungsort Editor  
  Sprache Sprache der Zusammenfassung Originaltitel  
  Editor der Reihe Titel der Reihe Kurztitel der Reihe  
  Band der Reihe Ausgabe der Reihe Edition  
  ISSN ISBN Medium  
  Bereich Expedition Konferenz  
  Notizen (down) GRO, Geprüft  
  Rufnummer Signatur 49  
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Autor Francis, R. I. C. C.   
  Titel Back-calculation of fish length: A critical review Typ Zeitschrift, Artikel
  Jahr 1990 Publikation J. Fish Biol Kurztitel der Zeitschrift  
  Band 36 Ausgabe 6 Seiten 883-902  
  Schlüsselwörter Fisch, Statistik, Regression, Längen..., Review, Wachstum  
  Zusammenfassung A review is made of the literature on the back-calculation of fish body length from marks on scales or other hard parts (otoliths, vertebrae, fin rays, etc.). Though the technique is widely used it does not appear to be well understood. Regression methods are commonly used, apparently in ignorance of the more realistic proportional methods. It is not generally recognized that there are two equally plausible back-calculation hypotheses which can lead to significantly different back-calculated lengths. The Fraser-Lee equation, the most commonly used back-calculated formula, follows neither of these hypotheses but is based on a misuse of linear regression. It is recommended that back-calculation be restricted to procedures following one of the proportional hypotheses; that the difference between lengths calculated using the two hypotheses is a useful measure of the minimum uncertainty in back-calculation lengths; and that more attention be paid to validating back-calculation hypotheses by comparing observed and back-calculated lengths for individual fish. The pattern of heteroscedasticity in body length-scale radius plots is noted as a useful diagnostic in evaluating back-calculation hypothesis.  
  Adresse  
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  Herausgeber Erscheinungsort Editor  
  Sprache Sprache der Zusammenfassung Originaltitel  
  Editor der Reihe Titel der Reihe Kurztitel der Reihe  
  Band der Reihe Ausgabe der Reihe Edition  
  ISSN ISBN Medium  
  Bereich Expedition Konferenz  
  Notizen (down) Fish. Res. Cent., Box 297, Wellington, New Zealand Geprüft  
  Rufnummer 530 Signatur 2329  
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Autor Walters, C.; Ludwig, D.   
  Titel Calculation of Bayes posterior probability distributions for key population parameters Typ Zeitschrift, Artikel
  Jahr 1994 Publikation Can. J. Fish. Aquat. Sci Kurztitel der Zeitschrift  
  Band 51 Ausgabe 3 Seiten 713-722  
  Schlüsselwörter Fisch, Fischerei, Statistik, Population, Mathematik, CPUE, VPA, Modell  
  Zusammenfassung The Bayes posterior probability distribution is a powerful way to represent uncertainty in fisheries stock assessments, and can be calculated for key population and policy parameters of practically any population dynamics model. But the calculation is unwieldy when probabilities are to be assigned to a large grid of parameter combinations. The computational burden can be reduced substantially by analytically integrating over at least two “nuisance parameters” that occur in most assessment models: the observation error variance and the catchability coefficient. This simplification allows the analyst and manager to focus more easily on population parameters (stock size, slope of recruitment curve) that are of direct policy interest.  
  Adresse  
  Organisation Abschlussarbeit  
  Herausgeber Erscheinungsort Editor  
  Sprache Sprache der Zusammenfassung Originaltitel  
  Editor der Reihe Titel der Reihe Kurztitel der Reihe  
  Band der Reihe Ausgabe der Reihe Edition  
  ISSN ISBN Medium  
  Bereich Expedition Konferenz  
  Notizen (down) Fish. Cent., Univ. British Columbia, Vancouver, BC V6T 1Z4, Canada Geprüft  
  Rufnummer 527 Signatur 2326  
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Autor Myers, R. A.; Cadigan, N. G.   
  Titel Statistical analysis of catch-at-age data with correlated errors Typ Zeitschrift, Artikel
  Jahr 1995 Publikation Can. J. Fish. Aquat. Sci. J. Can. Sci. Halieut. Aquat Kurztitel der Zeitschrift  
  Band 52 Ausgabe 6 Seiten 1265-1273  
  Schlüsselwörter Fisch, Fischerei, Statistik, Wachstum, Mortalität, VPA, Population, Mathematik, Modell  
  Zusammenfassung The statistical model used is extended to estimate abundance from commercial catch-at-age data for many of the major commercial fish species in the world. The model combines commercial catch-at-age data and research survey estimates of fish abundance; extends the model to allow correlated errors among ages within a year for the survey estimates of fish abundance. Method is formulated for modeling the fishing mortality on the oldest ages of the fish caught. Estimates are obtained using maximum likelihood. The level of correlation among ages is sufficiently large to produce large biases in the standard methods for some stocks. The statistical model that includes correlated errors greatly reduces bias and increases efficiency if the correlation in the estimation error is large.  
  Adresse  
  Organisation Abschlussarbeit  
  Herausgeber Erscheinungsort Editor  
  Sprache Sprache der Zusammenfassung Originaltitel  
  Editor der Reihe Titel der Reihe Kurztitel der Reihe  
  Band der Reihe Ausgabe der Reihe Edition  
  ISSN ISBN Medium  
  Bereich Expedition Konferenz  
  Notizen (down) Dep. Fish. Oceans, Sci. Branch, Box 5667, St. John's, NF A1C 5X1, Canada Geprüft  
  Rufnummer 528 Signatur 2327  
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Autor Hoenig, J. M.; Morgan, M. J.; Brown, C. A.   
  Titel Analysing differences between two age determination methods by tests of symmetry Typ Zeitschrift, Artikel
  Jahr 1995 Publikation Can. J. Fish. Aquat. Sci. J. Can. Sci. Halieut. Aquat Kurztitel der Zeitschrift  
  Band 52 Ausgabe 2 Seiten 364-368  
  Schlüsselwörter Altersbestimmung, Fischerei, Statistik, Methode  
  Zusammenfassung A common problem in fisheries science is the comparison of two methods for obtaining ages of individual animals. The authors suggest that if the overall level of agreement is low between two ageing methods used on the same sample of fish, then one can use a test of symmetry to look for evidence of systematic disagreement. A chi super(2) test is used to determine if the number of fish assigned age i from method 1 and age j from method 2 differs significantly from the number of fish assigned age j from method 1 and age i from method 2. Such a test can also be used to determine the range of nominal ages over which two methods appear to give comparable results.  
  Adresse  
  Organisation Abschlussarbeit  
  Herausgeber Erscheinungsort Editor  
  Sprache Sprache der Zusammenfassung Originaltitel  
  Editor der Reihe Titel der Reihe Kurztitel der Reihe  
  Band der Reihe Ausgabe der Reihe Edition  
  ISSN ISBN Medium  
  Bereich Expedition Konferenz  
  Notizen (down) Dep. Fish. and Oceans, P.O. Box 5667, St. John's, NF A1C 5X1, Canada Geprüft  
  Rufnummer 532 Signatur 2331  
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Autor Swain, D. P.; Sinclair, A. F.   
  Titel Fish distribution and catchability: What is the appropriate measure of distribution? Typ Zeitschrift, Artikel
  Jahr 1994 Publikation Can. J. Fish. Aquat. Sci Kurztitel der Zeitschrift  
  Band 51 Ausgabe 5 Seiten 1046-1054  
  Schlüsselwörter Fisch, Statistik, Population, Fischerei, Geographisch, Mathematik, Modell  
  Zusammenfassung The authors show that spatially uniform changes in abundance can affect catchability given certain models for the distribution of fishing effort, but that this effect is slight compared with the effect of changes in the spatial spread of fish distribution. An index of distribution is described that depends only on spatial spread: the minimum area over which a specified percentage of the population is spread. We tested the density dependence of this index using data on Atlantic cod (Gadus morhua) in the southern Gulf of St. Lawrence. Results depended on the percentage of the population for which the index was evaluated. The area containing most (90 or 95%) of the population was density dependent, expanding as population size increased. The area of highest cod concentration (i.e., the area containing 50% of the population) did not expand significantly as population size increased.  
  Adresse  
  Organisation Abschlussarbeit  
  Herausgeber Erscheinungsort Editor  
  Sprache Sprache der Zusammenfassung Originaltitel  
  Editor der Reihe Titel der Reihe Kurztitel der Reihe  
  Band der Reihe Ausgabe der Reihe Edition  
  ISSN ISBN Medium  
  Bereich Expedition Konferenz  
  Notizen (down) Dep. Fish. and Oceans, Gulf. Fish. Cent., Box 5030, Moncton, NB E1C 9B6, Canada Geprüft  
  Rufnummer 529 Signatur 2328  
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Autor Wang, Y. G.; Thomas, M. R.   
  Titel Accounting for individual variability in the von Bertalanffy growth model Typ Zeitschrift, Artikel
  Jahr 1995 Publikation Can. J. Fish. Aquat. Sci. J. Can. Sci. Halieut. Aquat Kurztitel der Zeitschrift  
  Band 52 Ausgabe 7 Seiten 1368-1375  
  Schlüsselwörter Fisch, Statistik, Methode, Vergleich, Wachstum, Bertalanffy, Faben  
  Zusammenfassung Estimation of von Bertalanffy growth parameters has received considerable attention in fisheries research. Since Sainsbury much of this research effort has centered on accounting for individual variability in the growth parameters. In this paper we demonstrate that, in analysis of tagging data, Sainsbury's method and its derivatives do not, in general, satisfactorily account for individual variability in growth, leading to inconsistent parameter estimates (the bias does not tend to zero as sample size increases to infinity). The bias arises because these methods do not use appropriate conditional expectations as a basis for estimation.  
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  Herausgeber Erscheinungsort Editor  
  Sprache Sprache der Zusammenfassung Originaltitel  
  Editor der Reihe Titel der Reihe Kurztitel der Reihe  
  Band der Reihe Ausgabe der Reihe Edition  
  ISSN ISBN Medium  
  Bereich Expedition Konferenz  
  Notizen (down) CSIRO IPP&P Biometrics Unit, CSIRO Div. Fish., Box 120, Cleveland, Queensland 4163, Australia Geprüft  
  Rufnummer 524 Signatur 2323  
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