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North Pacific Halibut Fishery Management The goal of management of a commercially important resource is to resolve the conflict between maintenance and exploitation. Unfettered exploitation often leads to disappearance of the resource, as in the cases of whales, passenger pigeons, and buffaloes. But management that is too conservative leads to inefficient use of the resource. One approach to the conflict in fishery management has been to use the idea of some maximal sustainable yield that can be taken from the fishery. Unfortunately, owing largely to unpredictable variations in the environment, maximal yields are usually not sustainable for very long. The management of the Pacific halibut by the International Pacific Halibut Commission (IPHC) is an example of the responsive (adaptive) approach to management. Addition- ally, in this case there has been strong commitment to an understanding of the biology of the species, and the activities of IPHC have been superbly documented, as has the biological information obtained. 137
Case Study DAVID POLICANSKY, National Research Council, Washington, D.C. INTRODUCTION The International Pacific Halibut Commission (IPHC) was established by a convention between the United States and Canada in 1923, which was revised in 1930, 1937, and 1953 (Bell, 1969) and again in 1983. (The commission was originally named the International Fisheries Com- mission and renamed in 1953; I use the abbreviation IPHC throughout.) The purpose of the Commission was to provide a mechanism for joint management of the Pacific halibut (Hippoglossus stenolepis Schmidt), whose abundance had been declining up to 1923. The management ob- jective, originally the maximization of sustainable yield, was changed in 1983 to the optimization of sustainable yield (R. B. Der~so, personal communication); the idea of "optimal" sustained yield includes the "qual- ity of the fishery," as well as the weight of the harvest (Roedel, 19751. The primary ecological problem has been stock assessment; some related issues have also been important. The Commission originally had four members and now has six, drawn from industry and government. Half the members are Canadian and half are from the United States. The Commission is supported by a scientific staff, headquartered in Seattle, with a full-time director appointed by the commissioners; a Conference Board composed of fishermen and vessel owners, which makes recommendations to the Commission with respect to regulations; and an Advisory Group composed of 14 fishermen, dealers, and fish-processors, half of whom are selected by the Conference Board and half by the Halibut Association of North America. Members of the Board participate in the Commission's meetings as observers. The history of IPHC can be traced in its many thorough reports and in other sources; the following account relies especially on Thompson and Freeman (1930) and Bell (19811. Until 1888, the Indians had conducted an important halibut fishery, with a catch probably exceeding 3 million pounds a year. The Northern Pacific Railroad was completed in 1888, and the Canadian Pacific Railroad in 1892. These new railroads profoundly affected the development of the halibut fishery by providing ready access to large markets for halibut in the East. Attracted by the new profitability of the Pacific halibut fishery, men and boats from the eastern fishery arrived, and the annual catch increased rapidly. The next 30 years saw depletion of known halibut banks, maintenance of yield by discovery and exploitation of new banks, and technical innovations. By the time of World War I, it was obvious 138
NORTH PACIFIC HALIBUT FISHERY MANAGEMENT 139 that, from an economic point of view, the banks were being overexploited. For this reason and because winter fishing was dangerous and expensive, a winter closed season was desirable to the fishermen. Thus, economic pressure was the impetus for the birth of IPHC. The institution of a closed season required international regulation, which required a treaty. Many attempts to enact fishery treaties between the United States and Canada had failed, because they included both conser- vation and unrelated economic considerations (such as reciprocal port privileges). However, when the halibut treaty was finally ratified in 1924, it contained only a conservation measure (a closed season) and provision for the establishment of IPHC. An IPHC report to the two governments in 1928 offered specific rec- ommendations for the development of the fishery and the conservation of the resource. The report detailed the decline in abundance of halibut in all the areas where they were exploited. It recommended establishment of management areas in each of which the total catch of halibut could be reduced until the yield was stable, with the amount of the reduction being responsive to the catch per unit of effort (CPUE); closure of the nursery grounds; prohibition of the use of destructive gear; extension of the closed season; provision for future modifications of the closed season; and li- censing of all vessels for statistical and other purposes. These recom- mendations, based on scientific activities of IPHC under the direction of W. F. Thompson (including tagging experiments, analyses of catch sta- tistics, and hydrographic studies), resulted in the Halibut Convention of 1930~ which gave IPHC broad regulatory authority. BIOLOGICAL BASIS OF MANAGEMENT The overriding issue here is the ecological problem of stock assessment, i.e., knowing how many fish are in the sea. If that is known and the catch is known, then the effect of fishing on the fish stocks can be determined. Other aspects of the biology of the halibut have also been studied and are discussed below. Assessment of Stock Knowledge of stock abundance is desirable if a fishery is to be moni- tored. The assessment of fish stocks is perhaps the major fishery problem and is often intractable. IPHC has relied heavily on CPUE as an index of stock abundance (Skud, 19781; but the catch has been measured in biomass (weight), rather than numbers of fish. Number of fish is also important, because declining numbers can be masked by increased growth rate if only information on biomass is used (Schmitt and Skud, 1978~. In part for that reason, mark-and-recapture (tagging) experiments have been done.