40 



Fishery Bulletin 91(1). 1993 



Figure 7 



Mean densities of rock sole Pleuronectes bilineatus larvae in 

 Auke Bay, Alaska during spring and early summer, 1986-89. 

 Error bars are 1SE; where no bars are visible, they are ob- 

 scured by the point symbol. 



strategy, characterized by prolonged production of lar- 

 vae, has been termed "bet-hedging" (Lambert & Ware 

 1984) or "ubiquitous" (Sherman et al. 1984). This strat- 

 egy is described as adaptive in situations where prey 

 availability is unpredictable. 



In Auke Bay, fish species reproducing in the spring 

 appear to follow two strategies: One group, typified by 

 walleye pollock and flathead sole, is clearly synchro- 

 nous, in the sense described above; whereas Pacific 

 sandlance and rock sole are examples of species that 

 could be termed "early" The early group can be de- 

 fined as those species that produce their larvae prior 

 to the peak in the spring phytoplankton bloom (before 

 mid-April in Auke Bay). It is possible that early spe- 

 cies in Auke Bay are following the "bet hedging" strat- 

 egy discussed above, as they could have been produc- 

 ing larvae throughout the winter. In that case our 

 sampling would have coincided with the end of their 

 production period. 



From mid-March through June, conditions in Auke 

 Bay are rapidly changing as the system passes through 

 two of the production phases — spring phytoplankton 

 bloom and herbivorous copepod maximum — that typify 

 nearshore subarctic marine environments (Smetacek 

 et al. 1984). In the pre-bloom period, the water column 



