Aspects of oxygen consumption and bioenergetics of the Atlantic halibut (Hippoglossus hippoglossus L. ) were studied under laboratory conditions. Resting oxygen consumption rate was monitored over 36 hour periods in Atlantic halibut while held individually in open system respirometers. Routine oxygen consumption rate was determined in small populations of tank held Atlantic halibut over 24 hour periods, through modification of tank systems as open system respirometers. Values for resting and routine oxygen consumption in this species were quantified and models Produced enabling the prediction of the energetic cost of homeostasis and spontaneousa ctivity for a range of fish size from 53g to 5861g, at temperatures of 6, 10 and 14°C. These results were ftirther used to form the basis of an energy budget equation for this species. PhotoPeriod influences on the periodicity of respiratory rhythm in both resting and routine oxygen consumption trials were determined through analysis of data recorded throughout the 24 hour daily period. The results indicated a cyclic respiratory rhythm, with peak oxygen consumption often observed nocturnally. The relevance of these results to culture of this organism are discussed. Post-prandial oxygen consumption and ammonia excretion were measured in small populations of tank held Atlantic halibut, these results contributing further information to the partitioning of energy within the metabolic and excretory components of the energy budget equation. Values for resting, routine and postprandial oxygen consumption in the Atlantic halibut were found to be low in comparison to roundfish species, but corresponded closely with literature data produced for other species of temperate marine flatfish. Activity patterns in small populations of Atlantic halibut were monitored over 24 hour periods in a specially constructed film unit. The results of this work showed dualistic patterns of activity over the diurnal cycle. Further elucidation of the energy budget was achieved through the determination of the metabolic costs of activity in the tank environment. Atlantic halibut were observed to remain at rest for periods of between 76% and 94% of any 24 hour period, with the time at rest dependent on fish size and stocking density. One 28 day trial was undertaken in which the components of the energy budget were measured simultaneously, and the balance of the budget investigated. Oxygen consumption, ammonia excretion, growth, feed consumption and faecal production were monitored within a purpose built experimental unit, and these values finther applied to the construction of an energy budget model. Finally, the oxygen consumption data of this study was ftirther applied to produce a model quantifying the water requirements of this species in a single-pass tank system, for the intensive culture of this species in the tank environment. Further development of these figures allowed the quantification of the pumping costs in an Atlantic halibut ongrowing tank system, and these figures were incorporated into a simple economic model. The results present some of the first bioenergetic data produced for this species, and this is an important step towards the development of an Atlantic halibut farming industry.

Thesis (M.A.I.S.)--Oregon State University, 1997. / Typescript (photocopy). Includes bibliographical references (leaves 99-107). Also available online.

This study examines the spatial evolution of the Eastern Pacific halibut fishery over the period 1888-1972 in terms of resource exploitation and vessel-port interaction and attempts to delineate the factors which brought about the observed patterns. Four distinct stages of development are identified: (1) a stage of spatial confinement and resource depletion characterized by corporate involvement and restricted vessel range, (2) a stage of spatial extension, company fleet decline, and independent fleet expansion, (3) a stage of spatial adjustment, quota control, and extreme competition, (4) a stage of further spatial extension, fleet decline, and maximum sustained yields. The spatial structure of the industry at each stage of development is shown to be a function of resource availability, fishing costs, and changes in halibut fleet behavior. The time-cost-distance factor between producing grounds and the landing/processing sector of the industry proved to be a critical factor in a fishery that was characterized by increased competition for annual quotas. Conceptual models of the industry's spatial structure have been developed to portray the major changes which occurred from one stage to the next. These in turn are further developed to conceptualize the evolution of the halibut fishery over the 1888-1972 period. / Arts, Faculty of / Geography, Department of / Graduate

At the 1996 World Fisheries Congress, Donald A. McCaughran declared seventyfive years of regulatory success for the International Pacific Halibut Commission. The Commission's mandate was to reverse the precipitous decline in halibut stocks that had become apparent in the 1910's, and save this fishery from economic extinction. The biologists and fishermen who sat on the Commission assumed that the appropriate biological target was the one that yielded the maximum sustainable harvest. Using a bioeconomic model of the fishery and regression analysis, I argue the Commission's use of global quotas to achieve its biological goal of maximum sustained yield was most certainly an economic failure. I also argue its policies were very likely a biological failure, as well. While arguably accomplishing its biological goal of the maximum sustainable yield in 1960, dynamic bioeconomic theory indicates their policies probably destabilized the biological fishery. The paper will first sketch the historical background of the industry. Then the regulatory history will be discussed. Then the economic literature will be reviewed as it applies to the Pacific halibut industry. Finally, the historical data will be examined and the proposition that the regulatory management of the halibut fishery was a success will be tested. The period 1928 to 1960 is covered as it provides both reliable data and a continuous period of regulation, at the end of which the biological goal of maximum sustainable yields was apparently achieved. In conclusion, I find that statistically the fishermen were insensitive to the direct effects of the quota and the total quantity of fish available, and instead responded to the quota's indirect effects on the fishermen's costs, which induced the inflow of greater fishing capital than otherwise would have occurred.

At the 1996 World Fisheries Congress, Donald A. McCaughran declared seventyfive years of regulatory success for the International Pacific Halibut Commission. The Commission's mandate was to reverse the precipitous decline in halibut stocks that had become apparent in the 1910's, and save this fishery from economic extinction. The biologists and fishermen who sat on the Commission assumed that the appropriate biological target was the one that yielded the maximum sustainable harvest. Using a bioeconomic model of the fishery and regression analysis, I argue the Commission's use of global quotas to achieve its biological goal of maximum sustained yield was most certainly an economic failure. I also argue its policies were very likely a biological failure, as well. While arguably accomplishing its biological goal of the maximum sustainable yield in 1960, dynamic bioeconomic theory indicates their policies probably destabilized the biological fishery. The paper will first sketch the historical background of the industry. Then the regulatory history will be discussed. Then the economic literature will be reviewed as it applies to the Pacific halibut industry. Finally, the historical data will be examined and the proposition that the regulatory management of the halibut fishery was a success will be tested. The period 1928 to 1960 is covered as it provides both reliable data and a continuous period of regulation, at the end of which the biological goal of maximum sustainable yields was apparently achieved. In conclusion, I find that statistically the fishermen were insensitive to the direct effects of the quota and the total quantity of fish available, and instead responded to the quota's indirect effects on the fishermen's costs, which induced the inflow of greater fishing capital than otherwise would have occurred. / Arts, Faculty of / History, Department of / Graduate