ment of a small-boat fishery (NPFMC, 1991a,b,c). Evidence of some of these problems can been seen in time series of the number of participants, season length, fishing effort, and CPUE. The number of participants in the halibut and sablefish fisheries reached a maximum of 3,883 in 1990 for halibut and 706 in 1988 for sablefish (Pautzke and Oliver, 1997).
The central Gulf of Alaska (IPHC Area 3A) has accounted for 37-51 % of the U.S.-Canadian commercial halibut catches since 1977. During this time, and despite a tripling of catch, the season length collapsed from 47 days to 2-3 days (Figure G.12). Using season length to manage fisheries becomes harder as effort increases and season length shrinks. If vessels had not been placed on trip limits after the first one-day halibut season opening in recent years, season length would have had to collapse even further to avoid overharvesting. A similar contraction of season length in response to increased fishing effort can be seen in the West Yakutat sablefish fishery (Figure G.13).
Gear conflicts can arise within or between gear types. Under the short derby seasons, conflicts between halibut and sablefish longline operations and other gear types were, by default, infrequent. Because trawling is very restricted in the Gulf of Alaska, conflict between gear types may be minor even under longer seasons. Conflict between users of similar gear can develop when some areas and times are more advantageous than others. The regulated open-access fisheries were characterized by a high incidence of lost and unrecovered fishing gear. The IPHC estimated that 1,860 “skates" (roughly 1% of the gear fished) was lost in 1990 and that the lost gear accounted for about 900 metric tons of halibut mortality (3% of the commercial catch).