Thesis (M.S.)--Oregon State University, 2001. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

No description available.

Thesis (M.S. - Soil, Water and Environmental Science)--University of Arizona, 2002. / Includes bibliographical references (leaves 109-111).

Thesis (M. S. - Soil, Water and Environmental Science)--University of Arizona, 2002. / Includes bibliographical references (leaves 175-187).

The Scottish brown trout (Salmo trutta L.) is identified as an important resource which requires responsible and continual management. This study was divided into two parts; an electrophoretic survey of wild trout populations in Scotland, and a quantitative assessment of the genetic component to growth rate in various stocks, grown under hatchery and farm conditions. Sixty wild populations were sampled by various methods. All fish were typed using brain, eye, heart, liver and muscle tissue and starch gel electrophoresis for thirty four enzyme loci, thirteen of which were found to be polymorphic. Gene diversity analysis was conducted on the data collected, 33% of the diversity being attributed to differences between populations, much of the variation was thought to be due to founder effects. Evidence is presented to support a hypothesis that the trout in Scotland are derived from two main post glacial invasion stocks. Future management strategies for wild stocks of Scottish brown trout are discussed. Growth trials were conducted at Howietoun fish farm in order to calculate heritability estimates for growth rate. Hierarchical and factoral crossing schemes were employed, using broodstock from three stocks. Heritability estimates for growth rate were found to be high and it was concluded, significant genetic gains could be achieved if growth rate was the only trait of commercial interest and truncated mass selection was adopted. Attempts were made to investigate the relationship between heterozygosity and growth rate in the hatchery populations. It was concluded that more data were required to make a meaningful assessment, but from this study little evidence exists for a positive correlation between heterozygosity and growth rate. Correlations between early life cycle stages and subsequent growth are discussed.

Thesis (M.S.)--Eastern Illinois University, 2009. / Includes bibliographical references.

Thesis (M. Sc.)--University of Canterbury, 2008. / Typescript (photocopy). "June 2008." Includes bibliographical references (leaves 74-84). Also available via the World Wide Web.

Thesis (Ph. D.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on Sept. 24, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Physiology, Cell and Developmental Biology, Biological Sciences, University of Alberta." Includes bibliographical references.

Thesis (Ph. D.)--Groningen, 1938. / "Stellingen" (3 p.) tipped in. Bibliography: p. [138]-143.

The Wilderness lakes system represents a segmented barrier lagoon and comprises three interconnected lakes; Rondevlei, Langvlei and Eilandvlei. The latter is further linked by the Serpentine channel to the Touw river and Wilderness lagoon. The role of these channels, as well as a sluice in the Serpentine, in structuring certain aspects of the ecology of the system was investigated. An analysis of the salt budget of the lakes suggests that the Serpentine dampens tidaI processes to such an extent that they play only a minor role in the overall budget. Furthermore, the channel between Eilandvlei and Langvlei prevents any tidal salt input to the upper lakes. Their estuarine environments are however maintained by salt inputs which occur when the mouth is closed. This unusual phenemenon means that the sluice may have a minimal effect on the salt budget of the system because it is only closed when the mouth of the lagoon is open. Environmental conditions in each of the lakes, the Touw river and Wilderness lagoon were compared in terms of their physico-chemical characteristics and submerged macrophyte communities. A principal components analysis suggests that the physico-chemical environment of each lake is similar. The Touw river however has a very different environment, whilst that of Wilderness lagoon has some similarities to both the lakes and the river. During the study macrophyte communities recovered from a major recession which occurred between 1979 and 1981 . Biomasses in excess of 1000g m⁻² were recorded in both Langvlei and Eilandvlei. In the latter however, macrophyte growth was less prolific than in the former, as some areas of the littoral supported no growth at all. Macrophyte encroachment in the channels is a major factor inhibiting water flow between the lakes. This encroachment is most severe in the Eilandvlei/Langvlei channel where macrophytes covered 80% of the channel's area.The dominant fish fauna throughout the system is composed of a marine/estuarine migratory component. In the lakes the Mugilidae and Sparidae are the most common families, whilst in the lagoon and Touw river predators such as Lichia amia and Argyrosomus hololepidotus also commonly occur. Eilandvlei serves as the initial nursery area for most migratory species. An estimated 52000 fish migrated up the Serpentine towards Eilandvlei during February 1984 . Most fish do not penetrate as far as Langvlei, and this can be related to macrophyte encroachment in the Eilandvlei/Langvlei channel. However, it is argued that should this channel be dredged and the macrophytes removed, the nursery potential of the system would not be greatly enhanced . This is because environmental heterogeneity, in association with an abundance of food in Eilandvlei, make this lake the most attractive nursery area to juvenile marine/estuarine fish.