Feed accounts for 40% to 60% of the operating costs of Pacific salmon farms. Presently, commercial diets for Pacific salmon in seawater are formulated according to the nutrient requirements of juvenile chinook salmon and digestibility information derived from studies on rainbow trout in fresh water. Information on feedstuff digestibility by Pacific salmon is completely lacking, regardless of life history stage. Hence, this thesis was undertaken to determine the apparent digestibility of organic matter, crude protein and energy in conventional and novel feedstuffs using post-juvenile chinook salmon (Oncorhynchus tshawytscha) in seawater. The validity of determining apparent nutrient digestibility using the "Guelph system" of fecal collection and chromic oxide (Cr₂O₃) as the indigestible indicator in the diet was assessed in experiment I. In this regard, fecal samples were collected either from a settling column affixed to each novelly designed digestibility tank at 6 and 18 hour intervals or directly from the terminal section of the intestinal tract by stripping or intestinal dissection. Digestibility coefficients were noted to be significantly increased (P<0.001) when the feces remained in the water for 18 hours instead of 6 hours, owing to nutrient leaching. The collection of feces directly from the fish resulted in lower digestibility coefficients than those found when feces were obtained from the "Guelph system". This was attributed to a flaw in the design of the digestibility tank drain system, whereby the feces did not settle quickly into the collection column. The problem was rectified before conducting the subsequent experiments described below. In three additional experiments on chinook salmon in seawater, the overall goal was to ascertain the organic matter, crude protein and energy digestibility coefficients and the digestible energy values for commercial sources of fish meal (herring meal, anchovy meal, menhaden meal, Norwegian low temperature fish meal), poultry by-product meal (two suppliers), feather meal, blood meal, dried whey, canola meal, soybean meal, soybean protein isolate, extruded wheat and wheat middlings. Also, three novel sources of rapeseed protein products (two types of glucosinolate-free canola meal and rapeseed protein concentrate) were evaluated in this regard. The initial minimum size of the chinook in these studies varied between 10.3 g and 40.5 g. The digestibility tank complex consisted of 27 open-circuit 150 L fiberglass digestibility tanks, each supplied with aerated, 8.0°C to 12.5°C filtered seawater at a rate of 6 L/min. The fish were fed by hand twice daily to satiation either a reference diet or a test diet (70% reference : 30% test ingredient). In some instances involving plant protein products, the test ingredient was included at two dietary levels (15% and 30%). Within each test, each diet treatment was assigned to three groups of fish using a completely random or randomized complete block design. Chromic oxide (0.5%) was included in all diets as the indigestible marker. At the end of each experiment, fish were sacrificed and their feces were removed either by stripping or intestinal dissection for comparisons of methodology. In general, the fish meals had higher available energy content for chinook salmon than the other animal and plant protein sources assessed. The importance of screening feedstuffs for potential nutritive value by digestibility measurements was particularly evident from an examination of the digestibility coefficients obtained for menhaden meal versus the other fish meal sources, the two sources of poultry by-product meal, wheat products, canola products and blood meal in this study. The assessment of soybean products, regardless of dietary inclusion level (15% or 30%), could not be ascertained in chinook salmon because of poor diet acceptance. Canola protein sources appear highly promising as partial or complete (in the case of rapeseed protein concentrate) replacements of fish meal, based on digestibility assessment. The use of the "Guelph system" for fecal collection resulted in organic matter digestibility coefficients similar to those obtained by intestinal dissection. Thus, nutrient leaching must have been minimal with the "Guelph system" and it is concluded that this is a satisfactory procedure for digestibility assessment using chinook salmon in seawater. / Land and Food Systems, Faculty of / Graduate

There has been much discussion of the merits and limitations of area licensing, i.e., a fishery management tool which restricts fishermen to certain geographic areas, in the British Columbia," Canada, salmon fishery. To date there has been little formal evaluation of the implications of this policy tool for salmon fishery management. In the reports by Pearse (1982), Sinclair (1978) and Fleet Rationalization Committee (1982) some insights on the subject are provided, but an evaluation in terms of specific criteria is lacking. This study evaluates five area licence configurations in the context of the B.C. salmon fishery. They are assessed based on evaluative criteria that cover the following subject areas: management operations; socio-economic effects; biological effectiveness; and economic efficiency. Each of these broad subjects are factored into specific elements, in which the emphasis is on the nature of the fishery and the resource. From the analysis it was found that the area licence configurations that factored the coast into two large harvest areas or the configuration that alienated small area(s) as test area(s) are most appropriate for the fishery. These configurations facilitated the attainment of management operations, socio-economic and biological goals, but not the economic efficiency goals. The other configurations, in particular those that factor the coast into a number of smaller harvest areas, result in exacerbating the problems with all criteria except economic efficiency and some biological factors. The appropriate area configurations for the B.C. salmon fishery would be the configurations that factors the coast into two large harvest areas; or the configuration where two or three small harvest areas are alienated from the existing harvest area. There are three fundamental reasons for this: (1) they are least disruptive (i.e., minimum impact on present harvest patterns, least politically sensitive, and minimum distributional effects); (2) they offer greatest flexibility to address political, economic, biological and social uncertainties; and (3) these area configurations provide the greatest ease of implementation and incremental adjustment of the status quo. Acceptance of these configurations will depend on the time horizon and the objectives of the decision makers. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

The principal focus of this comparative-historical study is the fundamental differences in the perspectives of the Indian, commercial, and sportfishing user groups. A second focus is the differences in outlook of the professions involved in the management of the fisheries, and how their management paradigms have developed over time. Evidence is presented on the social history of the fisheries, including their regulatory history and the manager-user relationship. Using the rich material presented by the participants in the Pearse Commission as a primary source, the perspectives of user and manager are outlined. In particular, the views users expressed on the emotional policy issue of TURFs are defined. A comparison of these views clarifies the major interests within the fisheries. Observation of the interactions between the user groups and regulatory authorities, both during and after the Commission, reveals the ability of these interest groups to lobby very effectively within the Canadian democratic system. The major social conflicts within the fisheries that are representative of the importantly different perspectives are: culture conflict, sportfishing/commercial fishing conflict, political ideological conflict, and conflict between profession frames. The most serious conflict is between Indians and other resource users. Indians have sought legal recognition of existing aboriginal rights in fishing, involving increased allocations to Indian users; other users greatly fear displacement as the resources are reallocated. As independent "co-management" planning procedures are being carried on simultaneously between Indian bands and government, and between commercial and sport groups and government, the objectives of the two often conflict. The result is a management and allocation process that remains extremely volatile and subject to such intensive lobbying that rational planning is difficult. The fisheries management and planning process could benefit from the greater inclusion of the social sciences, a move which would help describe with greater accuracy the complex human components of the fisheries. Such an approach would also seek to develop the potential of mediation and negotiation as a means of integrating a number of rational, professional frameworks with user group perspectives, and would imply a continuance in the recent shift from centralist to intermediary planning. It is suggested that crucial management decisions relating to "endangered" stocks of salmon be delegated to councils of professional biologists, for in such cases it is important that lobbying processes not be allowed to compromise conservation principles. Also, economists should assume management roles that can better accommodate, in the processes of policy making, the heavy overlay of politically-important social policies inherent in the fisheries. To date, intense negotiation and bargaining processes, involving both user groups and the management professions, have been effectively conducted on both a public and private level. These processes have promoted ongoing social learning which has had a positive effect within the B.C. salmon fisheries (examples are the Pearse Commission, MAC, CFIC, PARK, and the Canada/U.S. Treaty). These types of processes appear to lend themselves to the establishment of lasting bio-anthropological contracts, and the subsequent realization of more rational salmon fisheries management. A planning process focused upon reducing social conflict, through the development of ongoing negotiation processes between the many participants in the fisheries, is considered the most likely to succeed. Not only will this better maintain the generally good record of biological sustainability of the B.C. salmon fisheries, but also it will gradually enable the full development of their considerable economic and social potential. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

Data were collected from participating grow-out salmon farmers, processors, and the B.C. Salmon Farmers' Association, through interviews, and utilized to define a base farm. A microcomputer based spreadsheet model was constructed to capture the important biological and economic variables. The model details the operating costs and returns of a farm for five years, and assumes operating costs are consistent with the fifth year to provide cash flows for a total of 20 years. The financial analysis includes an examination of the net present values, the net farm income, and the internal rate of return. Results indicate that the base farm is a viable investment at a 6.9% discount rate. A sensitivity analysis is utilized to determine the critical variables in the operation of a grow-out salmon farm. The most sensitive variable turned out to be the growth rate of salmon. The base farm was found to be vulnerable to economic variables such as the product price, and the feed price. Other important biological variables are the feed conversion ratio and the mortality rate, both of which have a significant effect on the viability of the base farm. / Land and Food Systems, Faculty of / Graduate

An experiment was designed to determine whether the response of fish to graded dietary levels of essential fatty acids (n3) was affected by the total dietary lipid concentration. Juvenile coho salmon were fed practical diets varying in lipid source and total lipid content. The diets were fed in duplicate during a 27-week and a 12-week period ran in succession. The effects of the different dietary fatty acid concentrations on body fatty acids composition were determined after each period. The dietary fatty acid classes were expressed either as percent of the dry diet or percent of the dietary lipid. Analysis of the body lipid fatty acid composition was performed for neutral and polar lipid fractions. The effect of dietary fatty acid concentration on growth and mortality was determined over a 12-week growth study (period 2). A 24-hour saltwater challenge was performed at the end of period 2. It was used to examine the effect of dietary fatty acid concentration on saltwater tolerance. Dietary n6 and n3 fatty acids appeared to be selectively incorporated into the body polar lipid pool. Linoleate and linolenate underwent elongation and desaturation which resulted in the inhibition of the elongation and desaturation of 18:ln9. The neutral lipid pool served as a source of n3 fatty acids for the polar lipid when dietary intake was limited by low temperatures during period 1. The body neutral monounsaturated and 18:1 monounsaturated fatty acids consistently reflected the composition of the diet. The n3 fatty acid concentration in the neutral lipid was also directly related to the dietary fatty acid composition during period 2. The effect of dietary fatty acids on the body neutral or polar fatty acid composition did not depend on the manner in which the dietary fatty acids were expressed. There was also no significant effect of dietary total lipid concentration on the relationship between dietary fatty acids and their incorporation into the body lipids. The growth response was difficult to interpret because of the high mortality. There was a significant difference in mortality among treatments. A positive relationship between dietary concentrations of total n3 fatty acids or n3 highly unsaturated fatty acids and mortality became evident following analysis of the regression of mortality as a function of dietary fatty acid composition. The dietary fatty acid composition did not appear to alter the saltwater tolerance of the 1+ coho salmon. / Land and Food Systems, Faculty of / Graduate

In this study, a number of experiments were undertaken to investigate possible methods for effective improvement of the texture and flavour of canned late-run chum salmon. These included removal of the skin and bones from the fish, processing of the boneless-skinless steaks in retort pouches, brine treatment using two washes with an 8% salt solution for one hour each time, and a precanning treatment in which the boneless-skinless steaks were soaked in a solution of 10% tripolyphosphate and 2% brine for two minutes. Only fish of advanced sexual maturity were used. The canned salmon was steam processed at 120°C for 65 minutes in an FMC laboratory retort. This was based on a known commercial process for 307 x 115 cans. Heat penetration studies were carried out to design the process schedules for the pouched samples. It was found that the pouched product required 48% less thermal processing time than the canned product to achieve similar lethality. Sensory results showed that the removal of the skin and bones did not produce any significant improvement in the flavour and acceptability of the fish. There was no significant difference between the polyphosphate/brine samples and the untreated (control) samples for all attributes tested. The brine treatment also did not improve the texture of the samples. However, there was less detection of late-run flavour in the brine treated samples when compared to the control. Comments offered by panelists described these samples as having a salty/briny flavour. Pouched samples had a firmer, drier and more fibrous texture than the canned product. They also scored better in terms of late-run flavour. Acceptance of the fish however was only moderate. As a consequence, although this study demonstrated an improvement in the texture and flavour of the pouched late-run chum in comparison to the canned product, it was concluded that a more acceptable pouched product could probably be obtained by using late-run salmon of less advanced sexual maturity. Results of linear regression analysis showed that significant relationships were obtained between sensory firmness, fibrousness and chewiness and instrumental hardness, maximum slope and chewiness. However, none of the sensory parameters were well predicted by the instrumental results. / Land and Food Systems, Faculty of / Graduate

Salmon aquaculture is the rearing of salmonids for commercial purposes. These practices are typically carried out in saltwater farms located in coastal waters. The process of siting these facilities requires identifying and selecting areas that are economically, socially and environmentally suitable to locate them. Siting salmon aquaculture facilities has become a controversial resource management issue in British Columbia (B.C.), where distance-based criteria ultimately determine the location of these facilities. This thesis focuses on providing insights and concepts to inform and examine the salmon aquaculture facility siting process in B.C. It is argued that regulatory processes and outcomes in the context of a new industry could respond to mechanisms and factors that shape governmental agendas, illustrating how policy can behave reactively rather than in a precautionary manner. In this case, the outcomes of such reactive policies are reflected in siting criteria that yield implicit environmental and socio-economic disadvantages and tradeoffs. This way, siting criteria derive from expert judgements based on best available information while their associated uncertainties may lead to consider less-desirable sites while underestimating or overestimating risks, and overlooking important regional objectives, cumulative impacts and stakeholder values. The thesis further suggests that the future evolution of the salmon aquaculture facility siting process in B.C. could benefit from siting processes that have already been developed and implemented by other sectors. Different lines of reasoning that deal with processes of public negotiation, analytical decision-making and a systems' approach are explored as ways by which the salmon aquaculture facility siting process could evolve in the future toward creating more comprehensive policy. / Science, Faculty of / Resources, Environment and Sustainability (IRES), Institute for / Graduate

A computer simulation model was written to mimic the natural movement of salmon fry in Babine Lake, B.C.. Simulated distributions of fry were compared with field observations taken in 3 sampling periods during the summer and fall in 1967, 1968, 1971, and 1972, in order to evaluate the model's validity. Simulated distributions of fry, when random and heavily-biased movements were combined, were in reasonable accord with naturally observed distributions of fry in periods 1 and 2. In period 3 the model successfully produced a distribution similar to that naturally observed when the fry were programmed to undergo only random movement. Factors which might account for the various distributions of fry in different periods include the effects of current and innate behavioral responses of the fry to limnological conditions. In constructing my model, I assumed that fry travelled at speeds observed in the laboratory in still water. The model of fry dispersal in Babine Lake could be improved as more information is collected on the limnology of the lake and on fry behavior. In addition, the model has much generality and the techniques used may be applied to the dispersal of other organisms and to other lakes. / Science, Faculty of / Zoology, Department of / Graduate

The hypothesis was that salmon farming can be the basis for the establishment of a viable small business in British Columbia. The constraints on the establishment of a salmon farm imposed by government regulations, the availability of funds, and the market for pan-size salmon were presented and discussed. The pertinent biological knowledge associated with the rearing of captive salmon was summarized. A simple production model designed to produce approximately one-half million marketable, pan-size salmon within 15 months was derived from published accounts of studies at experimental fish farms. A hypothetical salmon farm was described in detail including estimates of the capital and operating costs associated with the farming and processing activities. The required information was obtained through interviews with knowledgeable members of the industry. The estimated revenues and expenses attributed to the hypothetical farm were analysed using pro forma financial statements to ascertain the financial position and the net cash flow which may be expected. The profitability of the farm was analysed by applying net present value and internal rate of return criteria to the net cash flow. Sensitivity analysis of the effect of changes to the product mix. market price, labour rate, feed price, tax rate, and stocking density upon the profitability of the farm was conducted. Estimates of the critical values of the above parameters which would allow the farm to be a feasible investment opportunity were derived. The conclusion is that pan-size salmon farming can be a feasible small business in British Columbia. / Business, Sauder School of / Graduate

A deterministic simulation model is used to explore the relationship between juvenile pink, chum and coho salmon growth and size-related survival in the Fraser River estuary. Parameters most sensitive to change are identified and the results related to proposals for enhancement. These results suggest that increasing the initial size of enhancement pink and chum fry, relative to the size of wild fry, prior to seaward migration and releasing them early in the spring may increase their chances of survival. If increasing total (enhancement plus wild) fry density decreases fry growth rate, the presence of enhancement fry in the estuary could reduce the survival chances of wild fry. The decrease in wild stock survival may not be apparent from estimates of adult return for many years due to errors in measurement and to the effect on survival of environmental variability. The model can be used to suggest and evaluate enhancement proposals. Areas needing further research are also indicated. / Science, Faculty of / Zoology, Department of / Graduate