The profitable rearing of the Atlantic salmon (Salmo salar L.) requires artificial diets high in carbohydrates or fats or both in order to avoid the high cost of protein feed; this practice is monitored by growth criteria such as animal length and body weight. The present study investigates the physiological state of hatchery-reared salmon smolts raised under cage culture conditions and fed a commercial pellet food of elevated carbohydrate content. Our results show metabolic disturbances that strongly suggest a diabetogenous situation: hyperglycemia, hypertriacylglycerolemia, some glucosuria and occasional ketonuria. Histopathological examination confirms the initial suggestion: significant reduction of the beta to alpha cell ratio in the islets of Langerhans, frequent alteration of the disposition of insular cells, hydropic changes in the B cells such as degranulation, vacuolization and nucleic pyknosis, evidence of hypertrophy and hyperplasia of B cells and pronounced neoformation of islet tissue. In addition, hyalinization of both the exocrine and the endocrine pancreas was observed as well as fibrosis, lipomatosis and microangiopathy of the exocrine acinar tissue and an increase in intrapancreatic nerve cell number. In conclusion, the smolts fed the pellet diet displayed a syndrome reminiscent of mammalian diabetes; a comparison is drawn between diabetes mellitus and the observed form of salmon diabetes. The study emphasizes the need to involve physiological criteria in the assessment of the suitability of artificial diets especially in the rearing of healthy salmon intended for restocking of natural environments.

The aim of this study, which is mainly osteological, is to clarify the status of the genera Cristivomer and Salvelinus. A morphometric and meristic study in conjunction with osteology was used to assess their phylogenetic relationships with other genera of Salmonidae. About 390 specimens of adult and adolescent fish and 268 eggs and fry were examined. Presently, seven genera are recognized in Salmonidae. The genus Cristivomer is separated from Salvelinus because of the shape of the supraethmoid, supramaxilla, subopercle, vomer, lingual plate, and caudal fin, and also the high number of pyloric caeca, presence of pearl organs, and breeding behaviour of the former. In the genus Salvelinus, S. alpinus (including various forms), S. malma, and S. fontinalis are distinguished. S. alpinus oquassa, previously known as S. marstoni, is considered a subspecies of S. alpinus. The two previously designated species S. oquassa and S. aureolus are synonymized with S. a. oquassa. S. timagamiensis is reduced to a sub-species of S. fontinalis. The genus Salmothymus is maintained. The genus Cristivomer is more generalized than Salvelinus. The species S. malma is intermediate between S. alpinus and S. fontinalis. For the first time a detailed osteological study of C. namaycush and several forms of Salvelinus is undertaken, and their relationships assessed.

Rates of mortality among young salmon passing through a high speed, model propeller, turbine operating under a 50 ft hydraulic head but under various, draft tube suctions are given. Effects, on both fish mortality and turbine performance, of admission of compressed air into the turbine at various locations to reduce the effect of cavitation (believed to be the major cause of fish mortality in the turbine) are discussed . At low turbine speed and low efficiency, admission of air immediately downstream from the blades reduced the mortality of fish substantially but at high turbine, speed, and high efficiency, the reduction was insignificant. At high turbine speed, the effect, on fish mortality, of admitting compressed air into the penstock and atmospheric air into the turbine draft tube through a 3" diameter steel pipe installed about 1 ft downstream of the blades are shown to be beneficial. Records of biological examination from some of the tests to determine the apparent type of injuries are included. An attempt has been made to correlate the turbine speed with the number of injuries likely to be caused by fish being hit by the blades.The effect of partial vacuum on fish is also given. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

As the requirements for vitamin “A” increased during World War II, the livers from the Pacific coast dog-fish (Squalua suckleyi) and the soup-fin shark (Galeorhinus galeua) became one of the principal sources of vitamin "A". Under the pressure of a high and increasing fishing intensity, the catch of these two sharks in British Columbia has dropped greatly during the years following 1944. Changes in the availability or relative abundance of the dog-fish and soup-fin shark caught in Hecate strait and the dog-fish caught off Barkley sound on the west coast of Vancouver island were determined from the analysis of the-individual tally slips or fish receipts of each fishermen's landing of the livers from these two sharks caught by sunken gill-nets. Methods employed in the analysis of the data to determine the availability, included the analysis of the total landings of the livers from each area under investigation; the average boat catches per month; and average boat catches per trip per month. The method of link relatives is used in the analysis and the catch per unit of effort off Barkley sound is determined. The availability or relative abundance of the dog-fish in Hecate strait was found to decline from 1943 to 1945 with a slight increase during 1946. The availability of the soup-fin shark was found to decline greatly from 1944 to 1946. In the year 1946, the soup-fin shark fishery in Hecate strait was almost a failure. The decline in the availability of the dog-fish and the drop in the average vitamin “A” per gram of liver oil is closely related to the removal or possible depletion of the older age classes from the population. On the west coast of Vancouver island, off Barkley sound the index of return per unit of effort (one sunken gill-net 75 fathoms long fishing over a period of 24 hours) indicated that the availability of the dog-fish has increased in each year since 1944. The sunken gill-nets (7 inch stretched mesh) were found to select; dog-fish greater than 76 cm. in length. Small dog-fish of no commercial value (less than 76 cm.) tend to pass through the meshes. / Science, Faculty of / Zoology, Department of / Graduate

Four separate non-empirical studies are presented together with an extensive preface which indicates their common elements. The first study is concerned with non-existence and instability of bionomic equilibrium as a potential explanation of the 'alleged' poor performance of the fishing industry. A comparative-static model is presented. The results suggest that biological and economic forces need not be compatible with equilibrium and stability. The second study examines the problem of welfare and fishery regulation. It is argued that the objectives and appropriate regulatory regimes must be determined by consideration of limitations on compensations the diverse objectives of various organizational structures, and the efficiency with which regimes can internalize the complex externalities involved. With respect to regulation by public authority, several devices are examined and a tax on catch is shown to be efficient. In accordance with modern welfare economics, the study stresses the need for explicit considerations of compensation of losers. The third study examines the problem of "sports versus commercial" fishermen. It is shown how freedom of access results, under normal circumstances, in losses of welfare in both types of activity. Optimal resource allocation typically requires that different users only be discriminated against if their fishing techniques warrant it. If freedom of access is maintained, discrimination may be justified but only if the benefits are measured on each case. Finally, the indirect method of measuring benefits is evaluated, and rejected for some old and some new reasons. Study four examines the logic of "share systems". Under conditions of certainty, we re-affirm the conclusion that in the absence of technical, administrative or legal constraints, share systems are prone to resource misallocation. When viewed purely as a device for allocating resources under conditions of uncertainty the share system is restrictive and imperfect (if we ignore transaction costs). The system can be rationalized when viewed as a compromise between risk-bearing and incentives. Thus the prime explanation offered for share systems is moral hazard". / Arts, Faculty of / Vancouver School of Economics / Graduate

This thesis investigates agrarian transitions within aquarian contexts by investigating livelihood transitions in a small rural fishing village in central Vietnam. Examined are powers at play that inform livelihood transitions as fishers and fish farmers respond by moving in and out of different production systems in order to maintain their fishing and fish farming livelihoods. This research reveals that aquarian transitions in Vietnam could follow a similar trajectory of agrarian transitions whereby smaller, less efficient production systems make room for more efficient economies of scale. In conducting a thorough and detailed empirical analysis of production systems, the socio-economic relations that shape production systems, and natural resource governance within the Vietnamese context, this research contributes to a better understanding of the knowledge surrounding fishery resources and livelihood options.

Entry-limiting regulations imposed on common property fisheries have been suspected of encouraging fishermen to substitute unregulated for regulated inputs. This imposes a cost upon society in the form of a reduced amount of resource rent generated by the fishery. Almost no research has been done to provide quantitative estimates of substitution possibilities and the associated degree of rent dissipation. The thesis provides the first estimates of the harvest technology for the British Columbia commercial salmon fishery, one of the first fisheries in North America to experiment with limited entry controls. Estimates of cross-price elasticities of input demand and of elasticities of intensity are given. These elasticities exhibit a greater degree of input substitutability than has heretofore been assumed in the theoretical literature. Two of the four vessel types used in the fishery are observed to be responsible for most of the resource rent dissipation. Potential rent for 1982 is shown to be $73.1 million. This represents 44% of the total value of the landed catch. Actual rent for the 1982 season is estimated to be -$42.8 million. A model of a fishing firm subject to input restrictions is developed in the thesis. The empirical model uses a flexible functional form proposed by Diewert and Ostensoe (1987). The major advantage of the normalized, quadratic, restricted profit function over the translog is its ability to distinguish differing degrees of input substitution between pairs of inputs, while imposing convexity in prices upon the functional estimates. The function is estimated for one output, three variable inputs, and three restricted inputs. Four samples are used which correspond to the vessel types that fish salmon. This allows rent to be calculated for the entire fleet, as well as for each of the components. The study of the salmon fishery is completed by addressing the important issue of rent dissipation. The actual amount of rent is established by using the predicted input demands of each vessel to calculate total fleet costs for the number of vessels that fished in 1982. This is compared to the potential rent that would be generated by an efficient fleet. To determine the characteristics of the efficient fleet, the optimal amount of (the restricted) net tonnage for each vessel is determined. Predicted output levels for each vessel are then used to calculate the minimum number of vessels required to take the 1982 harvest. This is done for each of the four vessel types. This exercise is repeated for two alternative scenarios, including the assumption of a greater degree of substitutability per vessel than actually found and a change in the distribution of catch among the vessel types. A comparison of rents generated in each scenario with an estimate of the actual rent from the 1982 fishery suggests that input-substituting activities of the fishermen may cause a substantial amount of rent dissipation. In addition, fleet redundancy and an inefficient catch distribution are found to contribute to the problem. The thesis concludes with a discussion of the implications for effective fisheries management. In particular, the findings of the research endorse the (Pearse) Royal Commission on Pacific Fisheries Policy (1982) recommendation of a fleet reduction scheme to be used in conjunction with a royalty tax on catch. On the other hand, evidence of input substitutability suggests that a vessel quota restriction might be successful in preventing some rent from being dissipated. / Arts, Faculty of / Vancouver School of Economics / Graduate

This thesis provides information relevant to fisheries in which there is a desire to establish fisherfolk organizations, but where individualistic social networks rather than social cohesion and community prevail. Such situations in small-scale fisheries are poorly documented, but may define limits to the feasibility of co-management. In the case researched, the government of Barbados is designing a fisheries management planning process, but there is insufficient information on the social and economic characteristics of the unmanaged, small-scale, commercial fishery for migratory pelagics to determine whether either a state-structured (bioeconomic) or a cooperative (co-management) approach is appropriate. As a contribution to solving this practical, interdisciplinary problem, this study examined: the fishery-related uncertainties perceived by fisherfolk and government officials in Barbados; the social strategies of atomism, personal networks and formal organizations that fisherfolk may use to cope with uncertainty; and, whether the most appropriate initial management planning approach is bioeconomic or co-management. Research was conducted in Barbados between November 1993 and September 1994 involving surveys, social network analysis, participant observation and the study of official documents. Uncertainties related to fish catch and price were perceived by the majority of fisherfolk to be the most problematic, and the analysis focused on the means of coping with these. Evidence of social atomism was weak. Social networks, which tended to be individualistically-oriented among fishers, boat owners and processors, but more cooperative among vendors, were prevalent. Attempts by the harvest sector to formally organize to obtain market power had failed, but efforts to use this strategy persist. The state was found deficient in fishery planning and management capability. Barriers to communication within the state, and between it and the industry were apparent. Due mainly to the prevalence of networks and the state’s deficiencies, the bioeconomic approach is judged to be inappropriate in this setting. Due mainly to the high level of individualistic competition, the repeated failure of harvest sector organizations, and barriers to communication, co-management is problematic but more likely to be successffil. An incremental, institution-building approach to co-management is proposed due both to the flexibility of this approach and to the current political and planning environment that favours participative initiatives. / Science, Faculty of / Resources, Environment and Sustainability (IRES), Institute for / Graduate

This thesis examines the Government of Newfoundland's decision to emphasize the inshore fishery at the expense of the offshore in the future development of the industry. The inshore fishery is labour-intensive and is composed of approximately 30,000 licensed fishermen who operate on a seasonal basis from Newfoundland's coastal communities. More than 10,000 privately-owned vessels - with maximum range of 50 miles - are deployed in this sector and account for 65% of total landed tonnage. These vessels do not exceed 65 feet in length and over 90% are under 38 feet long. In comparison, the offshore fleet is capital-intensive and is executed from less than a dozen ports by 80 corporately-owned trawlers that range from 120 - 210 feet in length. The 1,100 men employed in this sector fish year-round as far as 200 miles out to sea and take the remaining 35% of total landed tonnage. Apart from one major exception, each sector takes stocks that are not exploited by the other. A major portion of the cod resource, however, follows extensive migration patterns and is harvested by both sectors. This seriously complicates the Newfoundland fishery because cod is the single most important stock and accounts for approximately 40% of the dockside value of the total Newfoundland catch. The cod resource is in fact composed of a number of separate stocks but about 60% of the total cod catch comes from one stock complex. This complex is known as the 'northern cod' and only this cod follows extensive migration patterns. Thus the inshore-offshore fishery conflict is confined solely to northern cod. The inshore and offshore sectors are not on an equal footing regarding northern cod because the inshore sector depends upon the seasonal shoreward migration of the cod that escape offshore exploitation. The viability of the inshore cod fishery is therefore contingent upon the restriction of offshore harvesting to levels that allow adequate volumes of cod to migrate inshore. This issue has been a central problem in the Newfoundland fishery for some time but it has become critical since the extension of fisheries jursidiction to 200 miles in 1977 . The extension of fisheries jurisdiction is expected to result in a 250% increase in total landings by Canadian fishermen from 1977 to 1985. In Newfoundland, landings are predicted to increase from 400,000 metric tonnes to 1,000,000 metric tonnes by 1985. Northern cod is anticipated to form the bulk of this with landings expected to rise from 80,000 metric tonnes to 365,000 metric tonnes during this- period. The Government of Newfoundland is currently implementing strategies to deal with these increases but, before doing so, it first had to determine where the emphasis for the allocation of the expected increases of northern cod was to be placed. It decided that, since inshore fishing contributes more to the stabilization of rural settlement patterns and lifestyles, priority ought to be placed with this sector. To analyze whether this was justified, the fisheries management literature was reviewed in order to identify appropriate criteria for evaluation. The literature illustrates that the three fundamental concerns are with utilizing the resource on a sustained basis, maximizing economic efficiency and satisfying the social aspirations of the people. On this basis, the criteria listed below were considered. Resource-Related Criteria: (1) Ability to harvest cod. It is important to know if each sector is capable of harvesting the major portion of the total allowable catch of northern cod. If one sector is not, placing priority with it would be an inefficient approach to managing the resource. (2) Ability to ensure sustained harvesting. Fisheries management is concerned with sustained harvesting. If one sector displays a capability for stock depletion much greater than the other, it may not be the most attractive for the long term management of the resource. Thus, a second criterion is the physical ability of each sector to harvest cod without over-exploiting the stock. Economic Criteria: (3) Maximization of economic rent. The management literature outlines that a fundamental management concern is to maximize economic rent. A third evaluation criterion, therefore, is which sector harvests fish most cost-effectively for a given volume of catch. (4) Maximization of economic efficiency. Maximizing rent for a fishery is only an accepted measure of economic efficiency during periods of full employment. Otherwise, immobility of labour, low opportunity costs and the combination of fishing with supplementary activities may mean that efficiency is fulfilled by over-employment in a fishery. Therefore, a fourth evaluation criterion is which sector contributes most to economic efficiency through the creation of employment and compatibility with supplementary economic activities. (5) Plant utilization. The processors have pointed to the fact that one of their most important concerns is increased plant utilization. A fifth evaluation criterion, consequently, is an examination of the impact that each fishery sector has on this. Social Criterion: (6) Satisfaction of social concerns. An integral aspect of fisheries management is satisfaction of social aspirations. In the Newfoundland fishery, these include provision of employment opportunities and preservation of existing settlement patterns. A final criterion is how the two sectors compare regarding this. Examination of the available data illustrates that both the inshore and the offshore sectors have the ability to harvest the major portion of the northern cod. Inshore fishing, however, employs a less rapacious technology than offshore fishing and harvests only the migratory part of the resource. Thus, it runs a lower risk of over-harvesting. At the same time, data provided by Schrank et al (1980) indicate that the inshore fishery generates greater economic rents than the offshore, i.e. it is the most cost-effective approach to harvesting. Furthermore, because it is labour- rather than capital-intensive, inshore fishing creates more jobs and, because it is seasonal, also allows for a greater range of supplementary activities. Thus, it contributes more to "economic efficiency". The two sectors also differ respecting plant utilization. Offshore fishing provides year-round operability for a handful of plants whereas inshore fishing supplies over 150 plants but on a seasonal basis only. Since both sectors display an ability to harvest the major portion of cod, neither has any advantages as far as increasing total plant utilization is concerned. Offshore fishing centralizes plant activity, however, and the inshore fishery may have benefits here by contributing more to efficiency criteria in creating a greater number of part-time jobs which can be fitted in with other occupations. Finally, the inshore sector is more supportive of existing settlement patterns than the offshore fishery because it provides employment in all outports and, since it allows for traditional supplementary activities more so than the offshore sector, is also more compatible with rural lifestyles. In summary, the inshore sector outperforms the offshore regarding the generation of rent and the maximization of economic efficiency. It is also less likely to over-harvest the resource and more fully satisfies the social aspirations of the Newfoundland people. There are no distinct differences between the two sectors in their ability to harvest cod or their contributions to total plant utilization. The inshore fishery therefore surpasses or is at least comparable to the offshore sector in every criterion. On the strength of this, it is the conclusion of this thesis that the Government of Newfoundland has made an appropriate decision in placing emphasis on the inshore fishery. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

The exploitation of salmon resources was once central to the economic life of the Northwest Coast. The organization of technological skills and information brought to the problems of salmon utilization by Northwest Coast fishermen was directed to obtaining sufficient calories to meet the requirements of staple storage foods and fresh consumption. This study reconstructs selective elements of the traditional salmon fishery drawing on data from the ethnographic record, journals, and published observations of the period prior to intensive white settlement. To serve the objective of an ecological perspective, technical references to the habitat and distribution of Pacific salmon (Oncorhynchus sp.) are included. The aim of the work is to assess the relationship of salmon technology complexes to ecological conditions at fishery sites. It is an examination of the operating principles in traditional systems of salmon production. A model of the fishery is suggested: during migration anadromous salmon pass through a number of time and space segments where they can be intercepted by fishermen. A coincidence of appropriate elements will define a fishery site, i.e., the characteristics of the prey, accessibility to resource locations, natural features of the environment, and the enterprise of fishermen. The interaction of these and their constituent variables provides a range of selective strategies to be used, analyzed in this study with reference to specific Northwest Coast ethnic divisions and geographic locations. Twenty-four ethnic or areal divisions within the Northwest Coast culture area were studied. The results of the research are presented in Part One supported by distribution maps and illustrative materials. Lists of reference tables for each of twelve systems of salmon production are contained in an Appendix. Part Two includes technical information about Oncorhynchus sp. and its habitat. Part Three is an analysis of social, ecological, and technological elements in several stages of inter-relation, including an interregional comparison in the final section. An Index of Salmon Abundance and a comparison of selected resource areas provide statistical evidence (Appendix II and III). / Arts, Faculty of / Anthropology, Department of / Graduate