modern computer, overall modeling of a fishery 

 this complex is obviously severely limited by 

 available data, and the marginal cost of generat- 

 ing the necessaiy data is very high. In one 

 sense, then, the broader modeling exercise is 

 intended to provide some guidelines to the 

 limitations on the technique in dealing with 

 highly complex fisheries. 



On the other hand, the program is flexible 

 enough to permit specific consideration of im- 

 portant policy questions in separable segments 

 of the salmon fishery. For example, the Columbia 

 River, Puget Sound, and British Columbia 

 fisheries are plagued by serious problems arising 

 from the spectacular growth of the ocean troll 

 fishery. Since the trollers take large numbers 

 of immature fish, they do a considerable, though 

 unknown, amount of damage in returning under- 

 sized fish to the water. The troll fishery is 

 inherently highly inefficient from both biological 

 and economic points of view. A substantial 

 part of its catch is made up of two and three 

 year old chinooks and two year old cohoes 

 which would almost certainly gain substantially 

 more in body weight than would be lost to 

 natural mortality if allowed to mature another 

 year. It is possible, with a restricted model, to 

 test the biological and economic impact of the 

 elimination or limitation of the troll fishery in 

 specified areas under varying assumptions as 

 to the resulting net increment in weight and the 

 distribution of the troll catch among other 

 types of gear. This analysis is, incidentally, 

 crucial to another public policy issue of major 

 proportions — the allocation of chinook and 

 coho salmon among commercial and recreational 

 users. 



Earlier work by a University of Washington 

 team on the Puget Sound salmon fishery (Royce, 

 et al., 1963) indicates that modeling permits 

 surprisingly accurate prediction of the net 

 economic benefits and catch distribution effects 

 by area of different techniques for reduction of 

 gear and expansion of intraseasonal fishing 

 time. The earlier study was, for strategic rea- 

 sons, constrained by the assumption that any 

 reduction of gear must be proportional for each 

 type of gear. It is obviously desirable to develop 

 the capability to test quickly and inexpensively 

 the effects of altering gear mix by area and by 

 time period. Since any gear reduction program 

 in the salmon fishery will inevitably involve 



intensely partisan political negotiations, a 

 display of the impact of a wide range of alterna- 

 tives is essential if any progress is to be made. 

 Finally, the model can be used to predict the 

 Impact of recent court decisions requiring that 

 Indian fishermen must be granted a "prior 

 claim" on any total catch permitted under 

 regulation. 



THE PACIFIC HALIBUT FISHERY 



This fishery presents a far simpler set of 

 modeling problems. The stocks have been under 

 intensive study for more than 40 years, and a 

 wealth of reliable statistical information is 

 available on both the stock and harvesting 

 sectors. In addition, the use of standard gear 

 (whatever its economic validity) makes analysis 

 much simpler, as does the widespread use of 

 a standard accounting system for halibut vessels 

 devised by the Fishing Vessel Owners Associa- 

 tion. The fact that halibut is marketed almost 

 entirely in fresh and frozen form further 

 simplifies the analysis. The principal gain in 

 the modeling exercise for this fishery will be 

 the ability to incorporate badly needed studies 

 of the effects of introducing different types of 

 gear, potentially much more efficient, if and 

 when limitation of the number of operating 

 units becomes possible. It will also be possible 

 to introduce into the analysis the effect of 

 shifting many of the halibut vessels from their 

 present multipurpose form into larger, specializ- 

 ed units — a process which would almost 

 certainly follow any effective gear limitation 

 program. 



THE KING CRAB FISHERY 



It is doubtful that the king crab fishery will 

 be amenable to very effective empirical work 

 in the near future. Not only are data extremely 

 limited, but the fishery is based on a relatively 

 long-lived, slow-growing animal, and it is 

 currently in a state of disequilibrium. Con- 

 sequently, the fragmentary statistical informa- 

 tion on catch, effort, and economic returns 

 from the fishery cannot be considered representa- 

 tive of long term equilibrium values. Neverthe- 

 less, the situation in the king crab fishery with 

 respect to stock depletion is so serious, and the 



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