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Autor (up) Arnason, A. N.; Mills, K. H.   
  Titel Detection of handling mortality and its effects on Jolly-Seber estimates for mark-recapture experiments Typ Zeitschrift, Artikel
  Jahr 1987 Publikation Can. J. Fish. Aquat. Sci Kurztitel der Zeitschrift  
  Band 44 Ausgabe suppl. 1 Seiten 64-73  
  Schlüsselwörter Fischerei, Statistik, Mathematik, Modell, Mortalität, Jolly-Seber  
  Zusammenfassung Handling mortality occurs in mark-recapture experiments if animals handled and released in a given sample have a higher mortality rate than animals that were alive but not sampled. This violates the assumption of equal survival required for forming the Jolly-Seber estimates of population abundance, survival, and recruitment. The authors show that handling mortality can produce very large biases in these estimates, and we develop a test to detect it. They investigate the power of this test and find that quite large biases can be produced at handling mortality rates that are too low to be detected. They also recommend methods to prevent handling mortality from occurring in fish sampling experiments and methods to reduce bias in the estimates. The test and the bias corrections are applied to mark-recapture data for a lake whitefish (Coregonus clupeaformis ) population and to data from simulated mark-recapture experiment.  
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  ISSN ISBN Medium  
  Bereich Expedition Konferenz  
  Notizen Zool. Dep. Comput. Sci., Univ. Manitoba, Winnipeg, Man. R3T 2N2, Canada Geprüft  
  Rufnummer 531 Signatur 2330  
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Autor (up) 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.  
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  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 Inst. Environ. Stud., FM-12, Univ. Washington, Seattle, WA 98195, USA Geprüft  
  Rufnummer 526 Signatur 2325  
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Autor (up) 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.  
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  Bereich Expedition Konferenz  
  Notizen Leer Geprüft  
  Rufnummer Signatur 480  
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Autor (up) McGarvey, R.   
  Titel An age-structured open-access fishery model Typ Zeitschrift, Artikel
  Jahr 1994 Publikation Can. J. Fish. Aquat. Sci Kurztitel der Zeitschrift  
  Band 51 Ausgabe 4 Seiten 900-912  
  Schlüsselwörter fischerei, Population, Mathematik, Modell, Statistik, CPUE  
  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.  
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  Bereich Expedition Konferenz  
  Notizen South Australian Res. Dev. Inst., 2 Hamra Ave., West Beach, S.A. 5024, Australia Geprüft  
  Rufnummer 525 Signatur 2324  
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Autor (up) 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.  
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  Sprache Sprache der Zusammenfassung Originaltitel  
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  Notizen Leer Geprüft  
  Rufnummer Signatur 1116  
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Autor (up) 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.  
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  Bereich Expedition Konferenz  
  Notizen Dep. Fish. and Oceans, Gulf. Fish. Cent., Box 5030, Moncton, NB E1C 9B6, Canada Geprüft  
  Rufnummer 529 Signatur 2328  
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Autor (up) Thomas, Gregor; Eckmann, R., Reiner   
  Titel The influence of eutrophication and population biomass on common whitefish (Coregonus lavaretus) growth – the Lake Constance example revisited Typ Journal Article
  Jahr 2007 Publikation Can. J. Fish. Aquat. Sci Kurztitel der Zeitschrift  
  Band 64 Ausgabe Seiten 402-410  
  Schlüsselwörter Fisch, Felchen, Coregonus lavaretus, Maräne, Biomasse, Wachstum, Alter  
  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 Geprüft nein  
  Rufnummer Signatur 2991  
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Autor (up) 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.  
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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  
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  Bereich Expedition Konferenz  
  Notizen Fish. Cent., Univ. British Columbia, Vancouver, BC V6T 1Z4, Canada Geprüft  
  Rufnummer 527 Signatur 2326  
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Autor (up) Wang, Y.; Mervyn, R. T.; Somers, I. F.   
  Titel A maximum likelihood approach for estimating growth from tag-recapture data Typ Zeitschrift, Artikel
  Jahr 1995 Publikation Can. J. Fish. Aquat. Sci Kurztitel der Zeitschrift  
  Band 52 Ausgabe Seiten 252-259  
  Schlüsselwörter maximum-likeli, modell, capt-recapt, wachstum  
  Zusammenfassung The Fabens method is commonly used to estimate growth parameters k and l in the von Bertalanffy model from tag-recapture data. However, the Fabens method of estimation has an inherent bias when individual growht is variable. This paper present an asymptotocally unbiasses method using the maximum-likelihood approach that takes account of individual varibility in both maimum lenth and age-at-tagging. ...  
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  Sprache Sprache der Zusammenfassung Originaltitel  
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  Band der Reihe Ausgabe der Reihe Edition  
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  Bereich Expedition Konferenz  
  Notizen Geprüft nein  
  Rufnummer 463 Signatur 2264  
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