For several millennia man has in some way farmed his waters by holding fish captive in ponds. Not until the second half of the nineteenth century, however, as a result of a general concern in the industrialised nations that fishery stocks were declining, were serious attempts made to breed fish artificially. The most concerted of these attempts in Britain effectively began in 1873 when Sir James Maitland (1848-1897), a Scottish landowner, commenced experiments which evolved into the construction of the world's largest salmonoid piscicultural establishment. This operation, the Howietoun Fishery, sold its produce nationally on the open market, a new departure in pisciculture. It also advanced the piscicultural process scientifically in selectively breeding fish superior to nature's own. Maitland's work was not, in itself, particularly successful commercially. This was not, however, the result of commercial failure on his behalf but rather a reflection of his desire to develop pisciculture for the public good in an attempt to restock impoverished fisheries and to disseminate knowledge in the hope that others would be encouraged to imitate his example on a more commercial basis. Maitland's piscicultural work was highly important to the development of what has today become a significant global industry, though his contribution has not hitherto been recognised. The thesis intends to set out Maitland's piscicultural advances and their significance. It offers a detailed analysis of Maitland's entrepreneurship and casts its net wider to draw in some discussion of his work away from Howietoun, particularly on his membership of the Fishery Board for Scotland where it examines the debate over state support for nineteenth century British science. The thesis concludes with an analysis of the development of Howietoun in the seventy years after its founder's death. In addition to Maitland's own writings, the thesis uses evidence from Howietoun's general records, Maitland's family papers, Fishery Board for Scotland material, and a very wide variety of published sources.

Thesis (M.Sc. (Ichthyology & Fisheries Science)) - Rhodes University, 2008.

Includes bibliographical references. / "Submitted to Ohio Division of Wildlife." "The first objective was to determine the accuracy of field identification of individual fish to species and to assess the extent of hybridization between walleye and sauger ... The second objective was to assess genetic variation in both species ... " -- p.3. Also available in print.

Thesis (M.M.S.)--Memorial University of Newfoundland, 2003. / Bibliography: leaves 58-64. Also available online.

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An overview of stock-recruitment dynamics for major B.C. salmon (Oncorhynchus spp.) stocks is presented. Stock-recruitment patterns range from linear relationships to "Ricker" type relationships to no relationship at all. However, stocks for which there are accurate escapement estimates generally show patterns expected from stock-recruitment theory. It is concluded that errors in stock definition, mixed catch allocation, and spawning counts bias optimum escapement estimates downward so that poorly monitored stocks may become severely overexploited without being noticed. Because of poor escapement counts and/or difficulties in separating mixed catches, optimum escapements for many B.C. salmon stocks, which account for about half of the total B.C. production, cannot be estimated. Most stocks for which optimum escapement can be estimated are now being severely depleted. Restoration of these stocks by increasing escapement to optimum levels would increase the total catch by at least 40% of the current yield. Further, experimental management by increasing escapement appears to be the best policy for most of the other stocks. / Science, Faculty of / Zoology, Department of / Graduate

京都大学 / 新制・課程博士 / 博士(情報学) / 甲第25023号 / 情博第855号 / 新制||情||143(附属図書館) / 京都大学大学院情報学研究科社会情報学専攻 / (主査)教授 大手 信人, 教授 土居 秀幸, 教授 三田村 啓理 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DGAM

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This study examined the suitability of Florida largemouth bass (Micropterus salmoides floridanus) for introduction into Virginia and other mid-latitude waters by comparing the performance of northern (M. s. salmoides), Florida, and hybrid largemouth bass in a 342 ha south-central Virginia reservoir, Briery Creek Lake (BcL). Fingerling northern and Florida largemouth bass were stocked into Briery Creek Lake in 1986, following impoundment, and in 1987. Largemouth bass were collected for genotypic and performance analyses in the autumn and spring beginning in 1989 and ending spring 1991. Electrophoretic analyses demonstrated that hybrid largemouth bass (F1 and Fx) dominated the 1987-1990 cohorts and indicated that one or both founding stocks were genetically impure. Comparisons of electroshock catch composition showed no survival advantage for Florida largemouth bass (FLMB) age-1 and older and no differential vulnerability to angling among the four presumptive genotypes of largemouth bass in Briery Creek Lake. Age-O FLMB proportions declined over both winters (1989-1990 and 1990-1991) indicating relatively high first-mortality in the thermal regime of Briery Creek Lake (3,875 annual mean of heating degree days). Statistical comparisons of growth revealed no consistent differences among the respective bass genotypes, although survival and growth tended to be slightly higher for PI hybrid bass. The average total length of largemouth bass in BCL was below the state's average by age three. Total lengths of age-O FI and northern largemouth bass (NLMB) were higher than FLMB and Fx bass in October, perhaps as a result of earlier spawning among NLMB and between the subspecies. Relative weights of largemouth bass in BCL were generally below 95; and few significant differences in (Wr) were observed among the presumptive largemouth bass genotypes. The suboptimal condition (Wr) of largemouth bass in BCL coupled with the decline in growth and condition of bass with increasing age suggested inadequate prey abundance in Briery Creek Lake. Overall, Florida subspecific alleles did not increase in BCL over time, but the population genetic composition shifted toward an Fx mixture in the 1990 year class; future generations of largemouth bass should be dominated by Fx individuals. Results of this study did not demonstrate substantial performance differences among northern and Florida largemouth bass, and their hybrids, except for poorer first-year survival of the Florida subspecies. Therefore, this study provides no support for the continued introduction of Florida largemouth bass in Virginia or other mid-latitude regions. / Master of Science