VERTICAL DISTRIBUTIONS OF ZOOPLANKTON AND LARVAE OF THE PACIFIC HAKE (WHITING), MERLUCCIUS-PRODUCTUS, IN THE CALIFORNIA CURRENT SYSTEM

As part of an investigation of the vertical distributions of larval ha ke and potential food in March 1995, we used a pump to sample microzoo plankton larger than 73 mu m and an optical plankton counter (OPC) for zooplankton 250 mu m or larger, at depths to 250 or 300 m at eight st ations where larvae were found, and one other station. We also interca librated the two techniques for sampling potential food. Copepod naupl ii and copepodids dominated the microzooplanktonic biomass. The greate st fraction of larval hake was found in the 50-75-m layer, together wi th the greatest fraction of the potential food (by either mensural tec hnique) deeper than 50 m. The depth distributions of larvae and OPC-es timated zooplankton were positively correlated from 50 to 300 m, but t his relation was not significant between the larvae and potential micr ozooplanktonic food caught by pumping. Because of a great abundance an d relatively shallow distribution of larvae at one particularly rich s tation, however, there was an overall correlation between the abundanc e of larvae in a particular sample and the biomass of their food.