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Honsig-Erlenburg, W. (1998). Ökologische Erfolgskontrolle von Restrukturierungsmaßnahmen an Kärntner Fließgewässern (Vol. 1998).
Schlüsselwörter: Renaturierung, Fisch, Österreich
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Busch, W., & Kreymann, H. (1993). Die Issel und ihre Fischfauna: Erkundungen an einem Fliessgewässer in Nordrhein-Westfalen. Kleve: Boss-Verlag.
Schlüsselwörter: Renaturierung, Fisch, Vorkommen, Arteninventar
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Wichowski, F. J., Kästle, A., & Stelzer, M. (1995). Über den Einfluß von Renaturierungsmaßnahmen auf das Makrozoobenthon und die Ichthyofauna eines Mittelgebirgsbaches (Vol. 24).
Schlüsselwörter: Renaturierung, Fisch
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Mertz, G., & Myers, R. A. (1995). Estimating the predictability of recruitment (Vol. 93).
Zusammenfassung: A simple analytical technique is developed for estimating the predictability of recruitment, that is, correlations between recruitment and stage-specific mortalities or abundances. The method requires the input of estimates of the variability of stage-specific mortalities, which may be calculated from mean stage-specific mortalities by applying a published regression. It is shown that modification of this regression to compensate for sampling error in field measurements of abundance significantly reduces the estimated standard deviation of log-recruitment, which is an important factor in the predictability calculations. It is concluded that the prospects for predicting recruitment from egg or larval surveys or from environmental variables are quite poor for fish stocks showing the typical distribution of mortality across stages.
Schlüsselwörter: recruitment-; mortality-; developmental-stages; fishery-biology; fishery-management; environmental-factors; stock-assessment; Pisces-; population-dynamics; models-
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Hoenig, J. M., Prager, M. H., & Payton, N. B. (1989). Computer programs for investigating the effects of environmental events on a time series of recruitment. Department of Fisheries and Oceans, St. John's, Nfld. (Canada). Science Branch.
Zusammenfassung: Prager and Hoenig (in press) used a randomization procedure to test the significance of discrete environmental events, such as el Nino-Southern Oscillation events, on a time series of recruitment. Their procedure implicitly accounted for autocorrelation and other problems frequently encountered when trying to use a parametric testing procedure. In a follow up paper, Prager and Hoenig (in prep.) investigated the power of several randomization tests and compared them to parametric alternatives. This report presents the two Fortran computer programs used in these studies.
Schlüsselwörter: recruitment-; environmental-effects; computer-programmes; time-series; fishery-management
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Butscher, D. (1990). Zu den Quellen.
Schlüsselwörter: Recht, theorie, software
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Stein, H., & Herl, O. (1986). Pseudorasbora parva – eine neue Art der mitteleuropäischen Fischfauna (Vol. 36).
Schlüsselwörter: Pseudorasbora, Verbreitung, Neozoon, Fisch
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McCulillough, B. D., & Wilson, B. (1999). On the accuracy of statistical procedures in Microsoft Excel 97 (Vol. 31).
Schlüsselwörter: Programmierung, Statistik, Methode
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Kuhlins, S. (1995). Manipulierte Ströme – Ein- und Ausgabefunktionen in C++ selbst erweitern.
Schlüsselwörter: programmieren, c++, methode, Grundlage
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He, X. (1990). Effects of predation on a fish community: A whole lake experiment.
Zusammenfassung: Studies of predator-prey interactions have been limited to laboratories or relatively small scale field experiments because of logistic difficulties in large scale field experiments. Much evidence has suggested that predictions based on small scale experiments on predator-prey interactions may not be simply extended to large scales, e.g. whole system. This study was designed to examine predation effects on a prey fish assemblage at the whole lake scale. After a year of premanipulation study, northern pike (Esox lucius) were introduced into a small piscivore-free lake inhabited by 14 species of fishes. In the third and fourth years, the lake was divided by a large mesh fence and northern pike were introduced into one half of the lake. Predation effects on individual prey population were estimated for both direct effects (i.e., consumption of prey species) and indirect effects, including habitat changes associated with predator avoidance behavior, increase of emigration rates and changes of population size structure. The relative importance of direct versus indirect effects was examined using randomized intervention analysis along with a model that quantifies the indirect effects. Decreases of prey fish biomass due to increased emigration was at least as great as that due to the direct effect of consumption when prey biomass was high (>40 kg/ha) but not when prey biomass was low (<30 kg/ha). Significant indirect effects included dramatically decreased abundance of the dominant species (northern redbelly dace, Phoxinus eos), increase of some rare species (sunfish, Lepomis spp. and creek chub, Semotilus atromaculatus), and decreased mean sizes of redbelly dace. Indirect effects occurred rapidly and were most apparent immediately following the introduction of northern pike. Community responses to northern pike predation included changes of species composition, species diversity and community stabilities. The fish communities were significantly different among the pre-pike period, pike period and post-pike period. The greatest variance was related to abundances of redbelly dace and sunfish. However, predation effects on the prey fish community depended on the observational scales used to determine community structure. (DBO)
Schlüsselwörter: predation-; interspecific-relationships; freshwater-fish; population-dynamics; Esox-lucius; Phoninus-eos; Lepomis-; Semotilus-atromaculatus; freshwater-ecology
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