of each month a group of fishing units moves 

 from its initial location to the harvesting location, 

 operates there for a specified number of days, 

 and sells its catch to the processor which will 

 produce the maximum profit to the group. If 

 the processor cannot absorb the group's total 

 supply, the group sells what it can and moves 

 to the next most profitable processor and so on. 

 A group may only sell to the set of processors 

 linked to the harvester that owns the gi-oup. 



Any catch unsold at the end of the month is 

 recorded and discarded since it has no economic 

 value. The harvesting time for each group is 

 limited not only by harvester and regulator 

 decisions, but by the group's harvesting capacity. 

 Primary operating costs for the harvester built 

 into the model are distance costs, time costs, 

 harvest-proportional costs, and license fees. 



A processor is a managerial entity that 

 operates in one physical location, buying stocks 

 from harvesters, transforming them into finished 

 products, and selling them in markets. As the 

 program is now set up, each processor's share 

 of the market can be made to depend on his 

 previous market share and on marketing ex- 

 penditures and product price relative to those 

 of other processors linked to the same market. 

 The cost structure of the processors is in standard 

 accounting terms. 



A regulator is an agency that imposes restric- 

 tions on the activities of harvesters or processors 

 in any of the variety of ways now employed or 

 discussed in the literature. These include: 

 (1) license fees; (2) size limits; (3) gear efficiency 

 limits; (4) effort limits; (5) operating limits for 

 processors; (6) seasonal closures; (7) monthly 

 quotas; (8) annual quotas. 



The model can be i-un in either of two basic 

 operational modes: as a conventional computer 

 simulation model, with built-in decision-making 

 algorithms specifying the behavior of processors, 

 harvesters, and regulators; or with human inter- 

 vention at intervals to allow for intuitive and 

 heuristic decisionmaking. 



A stock is any type of renewable marine 

 resource. It is treated in the model as linked to 

 a given location, and the quantities available 

 to harvesters at any given time are computed 

 continuously. 



It should be stressed that each entity is a 

 subroutine, and can be designed to any degree of 

 complexity warranted by the purpose of the 



routine and the adequacy of the data base. 

 Similarly, the degree of detail for a readout on 

 monthly or annual bases can be predetermined. 

 The model can be programmed not only to 

 maximize specific objective functions, but can 

 accommodate dynamic feedback factors in assess- 

 ing different kinds of management alternatives. 

 It can also handle a wide range of spatial 

 distributions of stocks and harvesters without 

 difficulty. 



THE ANCHOVY FISHERY 



Figure 2 shows, in schematic form, a pre- 

 liminary version of the model of the California 

 anchovy fishery. This model reflects the activities 

 of the types of vessels presently exploiting the 

 fishery, and therefore attempts to deal with the 

 complications imposed by their harvesting of 

 bluefin tuna and mackerel as well as anchovy. 

 It is also complicated by the interaction between 

 the markets for sport fishing bait and for meal 

 and oil, both of which now absorb considerable 

 quantities of anchovy. Sufficient data are avail- 

 able to permit some preliminary conclusions as 

 to the economic return from this limited fishei'y, 

 which is now prosecuted at a level so low that 

 the more fundamental problems in the stock 

 sector are not really involved. These preliminary 

 findings suggest, as one might suspect, that the 

 return to vessels fishing for anchovy on a full- 

 time basis during a nine months open season 

 would be substantially more attractive than the 

 returns from mixed operations. 



Accordingly, the model which will be used to 

 test regulatory alternatives will probably be 

 based on the assumption that a specialized 

 fleet of vessels optimized for the anchovy fishery 

 will develop once catch quotas are established 

 at levels sufficiently high to induce long term 

 investment in fishing and processing equipment 

 by major firms in the meal industry. Preliminary 

 work in a dissertation by Dr. Dennis Paulaha 

 (1970) provides excellent data on the type of 

 vessel and gear best adapted to the fishery. 

 Work on the complex stock model is reasonably 

 well advanced, and it is expected that a fairly 

 sophisticated and realistic approximation to the 

 behavior of the anchovy stocks under various 

 rates of exploitation can be developed. 



The economics of the anchovy operation are 

 relatively simple to simulate, since total produc- 



31 



