(35 m of depth/min.). After fishing at depth for 3 seconds, the 

 net was retrieved at 20 m/min. (14 m depth/min.)- The angle of 

 stray of the towing cable was recorded every 3 seconds and 

 maintained at 45° (+3°) by adjusting the ship speed and course. 

 After reaching the surface, the net was washed down and the 

 samples preserved in 5% formalin buffered with sodium borate. 

 Flowmeter readings were made at the beginning and end of each 

 tow. Detailed descriptions of gear and methods are given by 

 Ahlstrom (1953), Kramer et al. (1972), and Smith and Richardson 

 (1977) . 



LABORATORY PROCEDURES 



Laboratory processing began with the determination of a 

 displacement volume for each sample (methods described in Staff, 

 SPFI, 1953 and Kramer et al., 1972). Zooplankton volumes 

 (including ichthyoplankton) of samples collected in 1963 are 

 presented graphically in Smith (1971). 



Sorting involved the removal of ichthyoplankton from the 

 sample and identification and separation of: eggs and larvae of 

 Pacific sardine and northern anchovy; larvae of Pacific hake; and 

 eggs of Pacific saury. Usually, each sample was sorted 

 completely; however, some of the samples were fractioned into 

 aliguots using a Folsom plankton splitter (McEwen et al . , 1954) 

 prior to sorting. Several criteria were used to determine 

 whether a sample was fractioned: typically samples containing an 

 abundance of thaliacians and coelenterates and exceeding 150 ml 

 in total plankton volume were fractioned (to 50%, 25%, 12.5%, or 

 6.2 5%) to approximate a reduced volume of 50 ml for sorting; 

 samples with an excessive guantity of fish eggs and/or larvae 

 were occasionally fractioned to expedite the sorting process in 

 order to meet scheduled deadlines. If the identified fraction of 

 an aliguot yielded rare or interesting species of fish larvae, 

 the remaining fraction was freguently sorted and identified with 

 the intent of finding additional specimens. Aliguot percentages 

 for fractioned samples from 1963 are listed in Table 1 under the 

 "Percent Sorted" column; 5.8% of the samples collected in 1963 

 were fractioned. 



A "standard haul factor" (SHF) was calculated for each tow 

 to make them comparable and allow estimations of areal abundance. 

 This factor adjusts the number of eggs or larvae in a haul to the 

 number in 10 m of water strained per meter of depth fished. If 

 the vertical distribution of the species has been encompassed, 

 then the adjusted value is eguivalent to the number under 10 m 

 of sea surface. The SHF is calculated for each haul by the 

 formula: 



2 Personal communication, James R. Thrailkill, National Marine 

 Fisheries Service, Southwest Fisheries Center, La Jolla, CA. 



