LOEB and ROJAS: ICHTHYOPLANKTON COMPOSITION AND ABUNDANCE 



once again noted to be among the abundant OL 

 taxa. It will be of great interest to see the recruit- 

 ment resulting from this 1985 anchoveta spawn. 

 If the 1985 anchoveta year class is relatively suc- 

 cessful during this period of continued large sar- 

 dine stocks, it will lend support to the idea that 

 the anchoveta-sardine population fluctuations 

 have been primarily regulated by low-frequency 

 hydrographic events. In a long-term context such 

 events may not be unusual to the Humboldt Cur- 

 rent area. Fish scales present in sediment records 

 from coastal Peruvian waters indicate that sar- 

 dine replacements of typically dominant an- 

 choveta stocks have occurred at infrequent inter- 

 vals over the past 11,000 years (De Vries and 

 Pearcy 1982). In light of this, the ecological 

 events of the past 20 years may be naturally oc- 

 curring, physically mediated, but probably fish- 

 eries enhanced, fluctuations in this hydrographi- 

 cally complex region. Because of our limited time 

 reference, we have not previously acknowledged 

 such fluctuations as being "normal". 



ACKNOWLEDGMENTS 



We extend our appreciation to Dick Parrish and 

 Andy Bakun, Pacific Fisheries Environmental 

 Group (SWFC/NMFS/NOAA), whose interest in 

 eastern boundary current comparison studies has 

 made this work possible. We also thank Rodolfo 

 Serra and Gary Sharp for their valuable com- 

 ments and discussions of the manuscript. Appre- 

 ciation is extended to numerous other people in- 

 cluding ship captains and crew and laboratory 

 assistants, especially Hernan Miles, who have 

 helped in sample collection and processing over 

 the 20-yr period. 



This work was funded by NMFS/NOAA Solici- 

 tation WASC-84-00075. 



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