Following the abatement of domestic sewage pollution xii in the lower Logan River , the fish population was investigated in terms of abundance, growth, fecundity, production, mortality, age class structure, species diversity, distribution and movements during 1970 and 1971. Three general groupings of fish were identified in the study area on the basis of species composition, abundance and distribution using a cluster analysis technique. These were located in 1) the tributary stream (7-Mile Creek) which previously transported sewage to the river and 2) above and 3) below 7-Mile Creek in the main stream of the Logan River. A "transition" population was present in the river near the confluence of 7-Mile Creek. Species diversity was predictable on the basis of four physical variables including percent riffle, a measure of bank cover, stream sinuosity and gradient. Percent riffle appeared to be the most important variable in predicting the "Trophic Condition Index" of the fish population. An information theory function was used to determine the extent of fish movement within the study area. Of the four dominant species in the river (carp, mountain whitefish, Utah suckers and brown trout) only the brown trout demonstrated an apparent response to the pollution abatement by reducing the extent of its movements at this time. Seasonal growth patterns were strikingly similar among the species examined with maximum growth occurring during the spring months. Extensive weight losses, attributed to high population densities and a decline in the invertebrate forage base, occurred during the summer of both 1970 and 1971, particularly in the older age classes of mountain whitefish and brown trout. Production of carp, mountain whitefish and brown trout and Utah suckers was assumed to approximate total fish production in the river. Whitefish production above and below 7-Mile Creek was estimated to be 3. 87 and 1.65 gm/m 2/yr respe ctive ly for the period June 1970 to May 1971. Carp production in these two areas was estimated to be 22.86 and 10.45 gm/m 2/yr for the same period. Brown trout production was estimated to be 5.94 gm/m 2/yr above 7-Mile Creek while production of Utah suckers in the study area was estimated to be 2-3 gm/m 2/yr. Weighted production for the entire study area was estimated to be 23.5 gm/m 2/yr. Evidence is presented which suggests that fish production has increased following the pollution abatement.

The green sunfish Lepomis cyanellus Rafinesque is a member of the sunfish family Centrarchidae. Curtis states that all members of the sunfish family are native only to North America, and are primarily warm-water fish. According to Jordan and Evermann the green sunfish is generally abundant in all suitable waters from central Ohio and Indiana to the Rio Grande. Forbes and Richardson five the general distribution of the green sunfish to be from the Great Lakes to Mexico, the Mississippi Valley, and everywhere in small sluggish streams except east of the Alleghanies and in Canada. The green sunfish is not native to Utah, but has been introduced in a number of ponds in the state. It is not considered important as a pan-fish because of its limited range and small size.

Introduced brook trout (Salvelinus fontinalis) are implicated as a primary factor leading to the decline in distribution and abundance of native cutthroat trout (Oncorhynchus clarkii). However, not all introductions are successful, suggesting local conditions influence the success of invasions. Therefore, I sought to determine the multi-scale factor(s) that influence brook trouts’ invasion success of native Bonneville cutthroat trout (Oncorhynchus clarkii utah) habitats in Mill Creek, Utah. I conducted patch occupancy surveys to determine watershed-scale brook trout and cutthroat trout distribution. I also determined the relative abundance of brook trout and cutthroat trout at the reach-scale by conducting three-pass depletion electrofishing surveys at ten index sites throughout the drainage. Upon completion of those surveys, I collected key watershed and reach-scale biotic and abiotic data twice during base-flow conditions. In addition, to determine watershed-scale population connectivity and the potential for upstream invasion by brook trout, I assessed fish movement using two-way weir traps. At the watershed-scale, stream slope appeared to limit brook trout invasion into some portions of the drainage. Intermittent stream-flows and extreme levels of stream slope (> 10%) appeared to limit cutthroat trout distribution. At the reach-scale, regression analyses indicated aquatic invertebrate abundance and low winter water temperatures may have influenced the abundance of brook trout, but my models explained little variation in cutthroat trout abundance overall. I observed high rates (74%) of site fidelity amongst brook trout, and mobile brook trout moved short distances (range=62-589 meters) overall. Cutthroat trout also exhibited high site fidelity (92%), but their movement was more variable, as few individuals moved long distances (up to 12.15 km). These findings will help prioritize cutthroat trout management actions in this watershed, and will be useful in determining why brook trout are successful invaders in some systems, yet remain in low and patchy abundance in others.

Nine hemoglobins from adult rainbow trout have been isolated by starch gel electrophoresis using a Trisborate buffer system, pH 8.7. Six fast and two slow anodally migrating hemoglobins, and one slow cathodally migrating hemoglobin were observed in all specimens. The nine hemoglobins have been purified by DEAE cellulose ion exchange chromatography followed by starch gel electrophoresis. The subunit structure of each purified hemoglobin has been partially examined by gel electrofocusing (GEF) in .5 percent polyacrylamide gels containing 8M urea and lmM dithiothereitol (DTT). Tetrameric combinations of one, two, three, and four polypeptide chains are present. Twelve hemoglobins have been isolated from cutthroat trout. Six fast and two slow anodally migrating hemoglobins, and four cathodally migrating hemoglobins were observed in most of the specimens. Hemoglobin polymorphism has been detected in a population of Yellowstone Lake cutthroat trout, Yellowstone Park, Wyoming. Six phenotypic patterns were evident.

Based on ethnographic fieldwork in the traditional commercial linefishery on South Africa’s southern Cape coast, informed by social-ecological systems (SES) thinking, and directed by a participatory action research approach, the work facilitated the co-development of a series of applied responses to local challenges identified by research participants including commercial linefishers, school learners, teachers, and other local community members. The thesis is presented in four chapters, each focussing on a different challenge: marine water temperatures; school learning for social learning; fishers’ organisations; and branding of linefish. The objectives of the thesis are to explore the processes, constraints, motivators, and lessons learnt in addressing each of the four challenges drawing on four emergent themes: 1) trust and social capital, 2) social learning, 3) resilience and transformation, and 4) participatory action research/co-development. The thesis underlines how participation leads to co-developed strategies to address realworld challenges. The work on water temperatures resulted in the co-development of a novel water temperature measuring device for deployment on commercial linefishing boats. However, despite initial successful deployment, fishers’ time and financial concerns, paired with a short-term focus undermined the participatory process. The social learning and teaching work facilitated the co-development of a series of integrated teaching modules that addressed challenges observed in the school, transforming the approach to teaching, and laying the foundation for future community social learning. The work also raised the challenge of ‘high stakes testing’ which may constrain teacher participation. The work on fishers’ organisations revealed the role of leadership, competing economic and lifestyle foci, competence and political trust, as well as ‘bonding’, ‘bridging’, and ‘linking’ forms of social capital in the formation, maintenance and dissolution of these bodies. The research found that different forms of trust and social capital, paired with leadership, were critical to successful participation and collaboration throughout the fieldwork. Finally, the branding work resulted in an adaptation on the part of the fishers, but one which was constrained by and highlighted the economic influence of inshore trawling that continues to limit the extent of linefishers’ adaptive strategies.

by Ho Sheck-kwong. / Title also in Chinese. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1980. / Bibliography: leaves 166-179.

The common wolffish (Anarhichas lupus), a benthivorous species, is widely dispersed, although not abundant in the North Sea north of 54ºN latitude. Despite being widely distributed in sub Arctic and cold North Atlantic waters, little is known of the ecology of this species in the North Sea. This thesis aimed to provide ecological information for this species at the southern limit of its range in the Northeast Atlantic. North Sea common wolffish are regarded as sedentary in habit and mainly inhabited depths ranging from 60 m to 150 m. The bottom temperatures where this species were found in the North Sea ranged between 3ºC and 12ºC. The common wolffish is a by-catch species for the North Sea bottom trawl fishery. The long-term catch data and CPUE (catch per unit effort) indicated that the stock abundance of North Sea common wolfish has been decreasing over the last decades. However, it is suggested from VPA (virtual population analysis) and Yield-per-recruit analysis, that the North Sea common wolfish stock is still in a safe condition but has been overexploited. The means of total mortality (Z), natural mortality (M) and fishing mortality (F) of this species for 1996-1998 were 0.47, 0.17 and 0.30, respectively. Both resting metabolic rate (RMR) and maximum metabolic rate (MMR) were low for this species. RMR and MMR were measured for six adult common wolffish (mean weight, 1.39kg) at 5ºC and 10ºC. At 5ºC the mean RMR± SE was 12.18 ± 1.6 mgO(_2),kg(^-1)h(^-1), and mean MMR ± SE was 70.65 ± 7.63 mgO(_2)kg(^-1)h(^-1). At 10ºC the mean RMR±SE was 25.43 ±1.31 mgO(_2) kg (^-1)h(^-1), and mean MMR ± SE was 113.84 ± 16.26 mgO(_2) kg(^-1)h(^-1). Absolute metabolic scope was 53% greater at 10ºC than at 5ºC.The main food for common wolffish in the North Sea were Decapoda comprising 39 % of the overall diet by occurrence, with hermit crabs (Paguridae) being the dominant species. Other important dietary components were Bivalvia (20 %) and Gastropoda (12 %). Sea urchins (Echinidae), which are important prey of common wolffish in eastern Newfoundland, Gulf of Maine and Iceland, but typically of low energy value, occupied only 7 % of the diet. During the autumn/winter season, wolffish consumed less food compared with the remainder of the year. From this study, von Bertalanffy growth parameters for common wolffish in the North Sea were calculated to be: for male, L(_oo)= 111.2 cm, t(_o) = -0.43 and = 0.12; and for female, L(_oo)= 115.1 cm, t(_o)= -0.39 and K = 0.11, making North Sea common wolffish the fastest growing stock of this species reported. The fast growth of North Sea common wolffish may be a result of the higher energy content of the diet or greater metabolic scope available for food processing. This increased metabolic scope being associated with life in the warmer North Sea, in comparison to those stocks found elsewhere in the range of this typically sub-Arctic species. The maximum age found for this species in the North Sea was 18 years old. Median length at sexual maturity of male and female common wolffish is at 51.9 cm and 50.4 cm respectively, with the age of sexual maturity being achieved at 4-5 years in the North Sea. The spawning season of North Sea common wolffish is from October through to February. The fecundity varied with the body weight of females, from several thousand to 12,000 eggs. Ripe egg sizes ranged from 5 mm to 6.5 mm. Spermatozoa were found in mature male individuals throughout the whole year with the highest peak in October.

Thesis(M.S.)--Auburn University, 2006. / Abstract. Includes bibliographic references.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2002. / Includes bibliographical references (leaves 221-228).

These (Ph.D.)--Dalhousie University, 2008. / Title from PDF title page. Abstract, table of contents in French and English. Available through UMI ProQuest Digital Dissertations. Includes bibliographical references (leaves 88-97). Also issued in print.