Zusammenfassung: The statistical model for the Petersen method is a hypergeometric distribution. Approximation to a binomial distribution has been used, and the usual method for this binomial model is based on approximation to a normal distribution. The Bayesian statistical model for a binomial distribution, which assumes that the prior distribution of parameters is uniform, corresponds well with the conventional method. However, the Bayesian statistical method for a hypergeometric distribution which assumes the uniform prior distribution is not feasible. The prior distribution according to the inverse squared parameter is natural for this model. Beta function and zeta function are important to understand these methods. This model is simpler to understand and easier to calculate by micro-computer than the conventional method.

Zusammenfassung: The SPECIESDAB manual describes the use of software created to assist in the retrieval of information relevant to species of interest to fisheries. Data on scientific and vernacular nomenclature, biology, fishing gears, and geographical distribution are included for species that belong to certain marine resource groups. This information is derived from the FAO Fisheries Department species identification and data programme publications and the software is designed to permit continual updating as new publications on other resource groups appear. To date, some 25 major resource groups are covered. Among these are shrimps, lobsters, cephalopods, sharks, marine turtles, and 20 families of bony fishes, which together form a significant component of world fisheries. The program uses a menu system to provide users easy access to the information contained in SPECIESDAB. The manual includes extensive examples of how to use the software. On-line help is also available. Extensive query and reporting capabilities are provided to access data on valid scientific names, synonyms, national and local names, official FAO trilingual names, size, habitat, behaviour, kinds of gear utilized in the fishery, and level of interest to fisheries. Geographical information may be obtained by species, by country, or by fishing area. Data may be extracted for either a single resource group or for all resource groups in combination. Furthermore, the user interested in using only the data of species occurring in a particular geographical area can create, with the Regional option, a sub-database including only the species found in the countries selected. This option can be useful for regional bodies and working groups. SPECIESDAB includes a bibliographic reference system, which may be updated by the user as well as utilities for exporting data.

Zusammenfassung: The growth curves of von Bertalanffy, logistic and Gompertz models were expanded using a periodic function, f (t + 1) = f (t). Each model was expanded into l = l infinity (1-exph sub(1)), l = l infinity /(1 + exph sub(1)) and l = l infinity exp(-exph sub(1)) where h sub(1) = -K(F(t)-F(t sub(0))), F' = f, f = (1 + a)/2 + (1-a)/2 multiplied by cos 2 pi (t-t sub(1)) : a less than or equal to f less than or equal to 1. BASIC programs for each model were written by Marquardt's method. The following subjects were also considered : an expansion into another type, a parameter-error analysis, a comparison with the original model and with Walford's graphical method, and a calculation to determine the extreme points of the growth rate. This expansion of the growth curves is useful and the programs are easily applied to other curves.

Zusammenfassung: The focus of this dissertation was the estimation of theoretical reference levels such as K, the environmental carrying capacity, and MNPL, the maximum net productivity level, for three fishes off Southern California and for the northern fur seal (Callorhinus ursinus) population of St. Paul Island, Alaska. The estimation techniques were based on computer modeling of historical population trends. The assessment of these theoretical reference levels for nature populations is fundamentally important to the development and testing of concepts in theoretical ecology and population dynamics. In the first study, maximum-likelihood estimates of pre-exploitation biomass were made for the white seabass (Atractoscion nobilis) and the yellowtail (Seriola lalandei) by assuming that development of corresponding commercial fisheries led to a shift in size distributions of these fishes, as indicated by records of the Avalon Tuna Club, Santa Catalina Island, California. Pre-exploitation biomass for Southern California populations of both these fishes was estimated to be about 20,000 tons. The pre-exploitation biomass of the giant sea bass (Stereolepis gigas) was estimated to be 1300 tons. Due to insufficient natural history information, this estimate was based on commercial catch records only. In the second study, estimates of theoretical reference levels for the northern fur seal population of St. Paul Island were based on computer simulations of pup production from 1912 to 1970, repetitive simulations were used to construct frequency distributions of estimates for MNPL, K, the number of pups born at MNPL and K, and the ratio MNPL/K. These distributions serve as a measure of the confidence that can be placed in single estimates of reference levels, and thereby provide a general context within which these reference levels can be evaluated. The final study of this dissertation investigated the pelagic migration of northern fur seal pups. Results indicated that initial migration paths for these pups are more widely dispersed than previously assumed. This information contributes to the understanding of northern fur seal life histories. A fuller understanding of life history information will eventually facilitate more accurate modeling of northern fur seal population dynamics. (DBO)

Zusammenfassung: The Desert Fishes Council has moved into the world of electronic publishing on the Internet. Dr. John Rinne (U.S. Forest Service, Flagstaff, Arizona) has allowed the first author to scan his well-known collection of fish photographs into digital format. They have been variously cropped and enhanced, and can now be viewed in different formats or downloaded by anyone in the world with Internet access. The second author is converting the Proceedings (staring with Vol. 24 [1992 meeting]) to hypertext format, so they may be browsed, searched or downloaded. All future DFC Proceedings will be published on WWW at the same time final hard copy is sent to the printer. The World Wide Web (WWW) allows anyone who has obtained free, public domain client software (readily available on Internet), primarily one called Mosaic, to browse effortlessly through multimedia files (graphics, video, sound, formatted text) that are stored on computers around the globe. Multimedia presentations can combine real-time sound, graphics and video with text. Exploration of WWW and the DFC system using Mosaic is facilitated by hypertext links, which offer the simplicity of “point and click” movement through the “cyberspace” of WWW. The Texas Memorial Museum of the University of Texas at Austin is providing storage space for these large DFC files at no charge as a pilot project for other WWW projects at UT, and can likely continue to provide this service for the forseeable future if it receives the usage and growth are predicted. All DFC members are encouraged to provide additional text, graphics and other files for inclusion in the system. Growth of the Internet has been phenomenal, and as more and more people throughout the world obtain access to it, these electronic files will allow DFC to better reach a far larger audience than was formerly possible. DFC members and others using materials provided here will be better equipped to educate the public regarding the plight of desert fishes. The system should also improve communications among ourselves and with others regarding fish conservation efforts throughout the world, and eventually should lead to reduced costs of publishing the Proceedings.