UBC Theses and Dissertations
Bioeconomics of Fraser River sockeye salmon fisheries Marsden, Allan Dale
Sockeye salmon (Oncorhynchus nerka) in the Fraser River are immensely important to British Columbia's culture and economy. Despite centuries of exploitation and decades of intensive study there remain several key uncertainties about the biological system, including those around dramatic four-year cycles of abundance and pre-season projections of how many fish will return in a given year. Recent years have seen declines in the productivity of some stocks as well as broader conservation concerns, leading to closure of some commercial fisheries, and it appears that greater economic beneﬁts may only be obtained if greater conservation risks are incurred. However, the existing literature contains no analysis focused on bioeconomic analysis of trade-offs between economic and conservation objectives in such complex multi-stock, multi-fleet fisheries. This dissertation develops a bioeconomic simulation model to examine these trade-offs. The model is applied to the Fraser River sockeye salmon fishery and parameterized using historical biological, fishery and economic data. In the first set of analyses, the fishery is simulated retrospectively from 1952 through 1998 and the economic outcomes of several management strategies are examined. In the remaining analyses the fishery is simulated 24 years into the future in a prospective analysis, assuming either that the long-term average productivity regime is still valid, or that recently observed changes in productivity are permanent. Given the outcomes of these simulations the trade-offs between economic beneﬁts and conservation risk are described. The retrospective analysis showed that if relatively simple harvest rules had been implemented historically, the fishery could have been 20-200% more profitable, depending on the particular harvest rule applied and the mechanism underlying stock dynamics. The prospective analysis under the long-term average productivity regime found that there is a policy region that would yield significantly greater economic beneﬁts than the currently applied policy while only minimally increasing conservation risk. Under the modified productivity regime, however, conservation risk is uniformly and unavoidably higher, and the trade-offs become more difficult in the sense that relatively more conservation risk must be incurred to obtain greater economic benefit.
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