predator levels , benefit to the nation from leaving anchovies 

 in the water is recognized. 



The California Current ecosystem, in which the northern 

 anchovy plays a major role at the forage fish level, is 

 characterized by large and visible populations of marine mam- 

 mals and birds. The endangered brown pelican, which may re- 

 quire high anchovy density for successful breeding, is noted 

 in the plan. While no specific action was taken, the plan 

 recommended monitoring brown pelican populations; funds for 

 monitoring are not guaranteed. 



Predator prey relationships involving anchovies, other 

 fish, mammals and birds received a very broad brush treatment, 

 particularly in comparison with the detailed social and eco- 

 nomic descriptive sections. The analysis of predator needs 

 and interactions was confined to the observation that during 

 1951-61 when spawning biomass was below 2 million tons (as. 

 opposed to the present 3-4 million tons) predators did not 

 appear to decline. For marine mammals, population data are 

 not available to support or refute this assumption. 



MSY for northern anchovies was estimated in the plan to 

 be 484,000 tons at an average spawning biomass of 1.8 mil- 

 lion tons. MSY was determined not to be a practical manage- 

 ment goal for this fishery because variations in recruitment 

 to the anchovy population are very large , and cause large 

 annual variations in population size and consequently in 

 sustainable yield. The plan concluded that to achieve MSY 

 would require a fishery with no catch two years out of three, 

 and extremely large catches in other years . Such variability 

 would be disruptive to the fishing industry. Consequently, 

 the OY formula designated in the plan was intended to allow 

 for high sustainable yields, but with less variability in 

 allowable catch from year to year than would be provided 

 under MSY. The OY formula in the plan is as follows: 



1. When the estimated spawning biomass is less than 

 100,000 tons, OY is 0; 



2. When the estimated spawning biomass is between 

 100,000 and 1 million tons, OY is 18,000 tons for 

 the non-reduction fishery catch (the reduction 

 catch, distinct from commercial live bait and 

 recreational catch, is processed for fish meal 

 and oil) ; and 



22 



