ZOOPLANKTON VOLUMES OFF THE PACIFIC COAST, 1957 



The six reports in this series that appeared under the author- 

 ship of "Staff of the South Pacific Fishery Investigations" contained 

 basic data for the seven-year period 1949 through 1955, but contained 

 no distribution charts. Distribution charts for all routine cruises 

 during these years were presented in Thrailkill, 1956, The report on 

 zooplankton volumes for 1956 (Thrailkill 1957) and the present report 

 for 1957 contain both basic data on zooplankton volumes and monthly 

 distribution charts of zooplankton abundance. 



Plankton samples are used by the U. S, Bureau of Commercial 

 Fisheries in studying the early life histories of commercially inqsor- 

 tant or potentially in^ortant fishes, including their distribution, 

 abundance, and rate of survival. These collections are also used by 

 Scripps Institution of Oceanography in studies of productivity. 



These investigations are part of the California Cooperative 

 Oceanic Fisheries Investigations, a program sponsored by the Marine 

 Research Committee and carried out by the Scripps Institution of 

 Oceanography of the University of California, the Bureau of Marine 

 Fisheries of the California Department of Fish and Game, the California 

 Academy of Sciences, the Hopkins Marine Station of Stanford University, 

 and the U. S. Bureau of Commercial Fisheries, Biological Laboratory, 

 La Jolla, California. 



The vessels participating on each of the California Cooperative 

 Oceanic Fisheries Investigations (CCOFI) cruises of 1957 are given in 

 text table 1, The Black Douglas, operated by the Bureau of Commer- 

 cial Fisheries made all the cruises between February and September 

 1957. Five vessels operated by the Scripps Institution of Oceanog- 

 raphy took part in CCOFI cruises during the year, A chronological 

 listing of CCOFI cruises for 1957, with information of the area covered 

 and the numbers of stations occupied, are shown in text table 2, The 

 stations occupied during 1957 are shown in figure 1. 



The table in this report serves a twofold purpose: 1) as a 

 record of basic haul data for all plankton hauls made during 1957, 

 and 2) as a record of the volume of plankton obtained in each haul. 



The information given for each plankton haul includes station 

 number (column 1), position (columns 2 and 3), date and time of collec- 

 tion (columns 4 to 6), volume of water strained (column 7), estimated 

 depth of haul (column 8), and volume obtained (columns 9 and 10). 



