TILLMAN and STADELMAN: SIMULATION MODEL OF ANCHOVY FISHERY 



3 when the inshore area is open, greater when it 

 is closed. Also, in three of four comparisons of 

 seasons within areas, an 8-mo season is less sen- 

 sitive to changes in stock-recruit relations than is 

 the 12-mo season. 



The greater sensitivity of the 12-mo season is 

 probably due to the greater level of effort exerted 

 (e.g., compare days fished) which would tend to 

 drive stock size down into more critical regions of 

 the stock-recruit curve and give rise to density- 

 dependent responses greater than those observed 

 under the 8-mo season. From a sensitivity view- 

 point then, harvesting-processing operations 

 planned for the 12-mo season or closed inshore 

 area would tend to suffer most from the present 

 lack of knowledge about stock-recruit behavior; 

 the 8-mo season or open inshore area would tend 

 to suffer least. 



Considering our premise that trade offs might 

 be made between quotas and areal-seasonal re- 

 strictions, the above model results imply that giv- 

 ing up (trading off) an increased season length 

 represents a considerable loss of potential 

 economic benefit. Such a trade off would therefore 

 seem to require substantial compensation in the 

 form of increased quotas. Trading off a change in 

 areal restrictions, on the other hand, would seem 

 to provide considerably less bargaining power. 

 Moreover, opening the inshore area appears to 

 offer distinct advantages, not only in terms of 

 moderately increased net returns, but also in the 

 form of somewhat decreased operating risk given 

 a lack of biological knowledge. Consequently, the 

 model indicates that trading off a change in sea- 

 son length appears to be the most advantageous 

 tactic for plant and fleet managers if they seek 

 increased quotas. 



Technological Change and 

 Employment 



In their study of the San Pedro wetfish"* fleet, 

 Perrin and Noetzel (1970) estimated that the 

 number of jobs on vessels had decreased from 381 

 in 1963 to 238 in 1968. The figures reflected a 

 reduction not only in the size of the fleet but also 

 in the size of crew as well. In 1963 the average 

 crew size was 10.29 compared to the 1968 average 



of 9.52. With such a decline in employment, it is 

 not surprising that the union opposes the intro- 

 duction of technology which would replace more 

 men (Stadelman 1974). 



According to Hester et al. (1972), the applica- 

 tion of a power drum to purse seining by the 

 wetfish fishery would significantly reduce the size 

 of the crew. Based upon the foregoing author's 

 experiment with a 100-ton (91-MT) capacity ves- 

 sel, Stadelman (1974) estimated that for a 210-ton 

 (191-MT) purse seiner the introduction of a power 

 drum would reduce the crew from 10 to 6. This 

 would result in significantly reduced vessel 

 operating costs (Table 9) which might allow fleet 

 expansion and a subsequent increase in the over- 

 all level of employment. Simulation experiments 

 were therefore conducted to see if a favorable out- 

 come resulted which might dissuade the union 

 from opposing such technological innovation. 



Table 11 lists the results obtained for a 12-mo 

 season for both the normal and the power drum 

 methods of purse seining. Use of the drum in- 

 creased net yield by 80% and the optimal level of 

 fishing effort by 38%. However, the optimal total 

 labor force was reduced from 544 required to man 

 the fleet to an estimated 459. Consequently, the 

 added vessels did not make up for the reduction in 

 crew size. 



However, it should be noted that even with the 

 use of the power drum the level of employment 

 would exceed its 1968 level of 238 men. It is also 

 apparent that the additional net yield associated 

 with the power drum, some $2.6 million, might be 

 negotiated into a wage above $12,000. On the as- 

 sumption that 459 men would be employed, each 

 could receive an additional $5,664/yr and the 

 fishery would still yield the same annual net re- 

 turn as before the innovation. Alternatively, the 

 increased net yield could supply income to employ 

 215 workers in other activities at the $12,000 

 wage, whereas prohibition of the power drum 

 would save only 85 jobs in the fishery. This is 

 the type of trade off that must be weighed in 

 determining policy to increase the level of 

 employment. 



^Wetfish are defined by Perrin and Noetzel ( 1970) to include 

 northern anchovy for reduction; and Pacific sardine, jack 

 mackerel, Trachurus symmetricus, chub mackerel, Scomber 

 japonicus, and Pacific bonito, Sarda chiliensis, for canning and 

 the fresh-fish market. 



127 



