The volume of water strained in making a haul was determined from 

 the formulation: 



V = R-a«p 



in which 



a - 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 revolution of the current meter (determined 

 from the appropriate current- meter calibration graph). 



R - total number of revolutions registered by the current 

 meter during a haul. 



V - total volume of water strained in cubic meters. 



The values for volume of water strained (in cubic meters), given in 

 the following tables, were determined from current-meter readings, except 

 for the few enclosed by 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 plankton volume of a sample was determined by displacement. The 

 plankton was separated from its preserving liquor, allowed to drain, and 

 then placed into a graduate containing a measured quantity of water. The 

 increase in volume was assumed to be due entirely to the drained but still 

 "wet" plankton. For comparability, the plankton volumes are expressed 

 as the "wet volume" in cc. per 1000 cubic meters of water strained. The 

 volumes are given under two headings: l) total volume, and 2) the volume 

 of smaller organisms remaining when jelly masses, fish, and larger mollusca, 

 squid, Crustacea, and the like were removed. 



The following tables are designed to serve a twofold purpose: l) to 

 record the plankton volumes obtained on the survey cruises, and 2) to re- 

 cord pertinent data for all hauls made during 1952, including the location, 

 date and time of collection, the volume of water strained (in cubic meters), 

 and the estimated depth of the haul (in meters). They differ from the 

 tables included in "Zooplankton Volumes off the Pacific Coast, 1951" 

 (Special Scientific Report: Fisheries No. 73, 37 pp., May 1952) In two 

 respects: l) a column has been added giving the estimated depth of each 

 haul, and "2) the unadjusted displacement volumes of the plankton have been 

 omitted. However, the latter values may be computed from the datr given 

 in the tables. 



