Zooplankton Volumes off the Pacific Coast, I956 



The six reports in this series preceding this one have appeared under the 

 authorship of the staff of the South Pacific Fishery Investigations. They 

 cover the seven-year period, 1949 throu^ 1955. Distribution charts for all 

 routine cruises made during these years have been presented in Thrailkill, 1956, 

 This report combines both the basic data on zooplankton volmnes and diatritaution 

 charts of zooplankton abundance for each cruise nsde in 1956 off the Pacific 

 coast of California and Baja California. 



Plankton collections are used by the South Pacific Fishery Investigations 

 of the Fish and Wildlife Service in studying the distribution and abundance of 

 the egg and larval stages of the Pacific sardine and other commercially impor- 

 tant or potentially important fishes, Basic data on fish eggs and larvae are 

 given in a yearly series of reports in Special Scientific Report — Fisheries 

 viiich parallel those on plankton volumes. Plankton collections are also used 

 by Scripps Institution of Oceanograf^y of the University of California in 

 studying the productivity of spavming areas. 



The research vessel. Blade Douglas . operated by the U, S. Fish and 

 Wildlife Service made all cruises betv/een February and September, Five 

 vessels operated by the Scripps Institution of Oceanography nade cruises 

 during 1956. The vessels participating in each cinise vrere as follows: 



""■Special cruise 



