A case study of the chum salmon (Oncorhynchus keta) gauntlet fisheries in Southern British
Columbia is described. Acrimony between industry and government managers has been
commonplace in the management of this fishery. In an attempt to alleviate this acrimony, a
management system call the "clockwork" has been implemented, which provides all fishermen
an opportunity for greater understanding of the management rationale and greater input into
the decision-making process. The clockwork has been generally successful; the stocks are
rebuilding and the fishermen are involved in the management of the fishery.
However, two problems are identified in the clockwork. First, the success of the clockwork
in alleviating the aaimony associated with the chum fishery depends on the ability of
fishery managers to provide sound and scientifically defensible in-season stock assessments.
If the assessments have no better track record than the intuition of managers and fishermen
then the clockwork will not be successful.
Second, there is a nagging problem of allocation of harvests between the mixed stock
fishery in Johnstone Strait and the terminal fishery in the Fraser River. The main factor is the
difference in price behveen the two fisheries; the price in the terminal fishery is only about
one-third of the price paid in the mixed stock fishery, Dynamic programming techniques are
used to determine the optimal harvest strategies for this gauntlet fishery. Generally, the optimal
strategy is similar to a fixed escapement strategy when both stocks are equally abundant.
But when one stock is much more abundant the optimal strategy is to harvest harder in the
mixed stock fishery. With the current difference in value per fish between the two fisheries,
the optimal exploitation rates in the terminal area are zero, all the catch is taken in the mixed
stock fishery. The minimum price at which terminal fisheries provide long term economic
benefit is the threshold price. For the parameters used to describe the current fishery, the
threshold price is approximately 40% of the mixed stock fishery price. Furthermore, the
threshold price differs with stock recruitment parameters, especially stock productivity
and recruitment variability. Generally the more similar the stocks are, with respect to stock
and recruitment characteristics, the lower the threshold value for fishing in the terminal areas.
The results provide a basis for discussion of the utility of terminal fisheries, and by
adjusting the relative value of the terminal fishery in relation to the mixed stock fishery can
incorporate additional social and aesthetic values, as well as costs such as harvesting costs and
fisheries management costs. / Science, Faculty of / Zoology, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/42065 |
| Date | January 1990 |
| Creators | Luedke, Wilfred Harold |
| Publisher | University of British Columbia |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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