Each plankton net is provided viV an Atlas-type current meter, sus- 

 pended in the center of the mouth. Each current meter was calibrated 

 before and after the cruise on which it was used, Tue volume of water strained 

 during a net tow was determined from the formulation? 



V B R*a,p 



in which 



a s the cross-sectional area of the mouth of the net, in square meters. 



p * length of the column of water in meters needed to effect one revo- 

 lution of the current meter (determined from the appropriate 

 currtnt meter calibration graph), 



R • total number of revolutions registered by the current meter during 

 a haul. 



V * total volxme of water strained, in cubic meters. 



Values for the volumes of water strained (CM,), given in the following 

 tables (column 7), were determined from current meter readings, except for 

 the few enclosed in parentheses, for which reliable current meter data were 

 lacking. For such hauls, an approximate value of "R" was obtained, which 

 represented the average performance of the current meter at the speed and 

 for the length of time of the tow. 



The following tables are designed to serve a twofold purpose; (1) to 

 record the volumes of plankton collected during the 19^3 survey cruises, and 

 (2) to put on record the data for all plankton tows made during 1953, in- 

 cluding station number (column 1), location (columns 2 and 3), date and time 

 of collection (columns U-6), volume of water strained (column 7), and the 

 estimated depth of the haul (column 8), 



These investigations are part of the California Cooperative Oceanic 

 Fisheries Investigations, a program sponsored by the Marine Research Com- 

 mittee, 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 Acadeity of Sciences, the Hopkins 

 Marine Station of Stanford University, and the South Pacific Fishery Inves- 

 tigations of the Fish and Wildlife Service, 



Three earlier publications deal with plankton volumes collected on survey 

 oruises of the California Cooperative Oceanic Fisheries Investigations, These 

 are? 



STAFF, SOUTH PACIFIC FISHERY INVESTIGAnONS 



1952, Zooplankton volumes off the Pacific coast, 1951. U, S, Dept, 

 Interior, Fish and Wildlife Service, Spec, Sci, Rept, s Fisheries, 

 No, 73, 37 pp. 



1953. Zooplankton volumes off the Pacific coast, 1952, U. S. Dept, 

 Interior, Fish and Wildlife Service, Spec, Scio Rept.i Fisheries, 

 No, 100, hi pp. 



195U, Zooplankton volumes off the Pacific coast, 19ii9-50o U. S, 



Dept. Interior, Fish and Wildlife Service, Spec, Sci. Rept,s 

 Fisheries, No, 125, 5h pp. 



