Manag ement objectives adopted in the plan were to : 



1. Prevent overfishing of the central subpopulation 

 within the U.S. FCZ and waters under Mexico's jurisdiction; 



2. Allow a fishery for anchovies within the U.S. FCZ 

 limited to achieve OY on a continuing basis; 



3. Maintain an anchovy population in the U.S. FCZ suf- 

 ficient to sustain adequate levels of predator fish, birds 

 and mammals ; 



4. Avoid conflicts between U.S. recreational and com- 

 mercial fleets; and 



5. Promote efficient utilization of the central subpop- 

 ulation of anchovies within the U.S. FCZ. 



MSY was not considered meaningful for the anchovy fish- 

 ery, since "maximum" and "sustainable" tend to be mutually ex- 

 clusive in this case. Because of large variability in re- 

 cruitment, the population level is usually under or over that 

 producing MSY. An MSY of 484,000 tons was estimated in the 

 plan for an average spawning biomass of 1.8 million tons. To 

 maximize total yield over time, a policy of catch smaller 

 than MSY when the population is below 1.8 million tons spawn- 

 ing biomass, and greater than MSY when the population is above 

 that figure, would be used. Unfortunately because of the 

 variability in anchovy biomass , maximizing total yield over 

 a long period of time would require a tremendous variability 

 in the fishery, from no catch 2 years out of 3 , to extremely 

 large catches in other years . Such variability would be 

 disruptive to the fishing industry. Another problem with 

 managing for MSY is the unusual sex ratio of the reduc- 

 tion fishery catch. The disproportionate catch of females would 

 lead to a greater impact than predicted. 



Ecological interactions : Northern anchovies are a large 

 part of the forage consumed by predator fish and inverte- 

 brates, some of which are fished recreationally and commer- 

 cially and eaten by marine mammals and birds . Anchovies them- 

 selves consume large quantities of fish eggs and larvae. No 

 assessment of the impact of the removal of anchovies on the 

 ecosystem was considered possible because of the complexity 

 of the system and the superficial knowledge of it. 



Status : The central stock spawning biomass was estimated 

 at 3 . 6 million tons in 1975. The 1974 year class was weak 

 and the 1975 class was poor. The 1976 year class appears to 

 have been considerably stronger. Overall abundance seems to 

 I 



F-9 



