net to the towing cable above the 34 kg terminal weight suspended 

 below the surface. The net was lowered to ca. 210 m depth by 

 paying out 300 in of wire over a 6 minute period (35 m of 

 depth/min) . After fishing at depth for 30 seconds, the net was 

 retrieved at 20 m/min (14 m depth/min). The angle of stray of the 

 towing cable was recorded every 30 seconds and maintained at 45° 

 (±3°) by adjusting the ship speed and course. After reaching the 

 surface, the nets were 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 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). 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. Some 

 samples were fractioned into aliquots using a Folsom plankton 

 splitter (McEwen et al., 1954) prior to the sorting. Criteria for 

 fractioning were: 1) samples taken at a distance greater than 200 

 nautical miles from shore were not fractioned, 2) samples taken 

 closer than 200 miles from shore and containing 25 ml or less of 

 plankton were not fractioned, and 3) samples taken closer than 200 

 miles from shore and containing more than 25 ml of plankton were 

 fractioned to 50% of their original volume (J.R. Thrailkill, pers. 

 comm.). Aliquot percentages for fractioned samples from 1984 are 

 listed in Table 1 under the "Percent Sorted" column; 41% of the 

 samples collected in 1984 were fractioned. 



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

 make them comparable and allow estimations of areal abundance. 

 This factor adiusts 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 equivalent to the number under 10 m^ of sea 

 surface. The SHF is calculated for each haul by the formula: 



SHF = 10 D 

 V 



where D = depth of haul = cosine of the average angle of 

 stray of the towing cable multiplied by cable 

 length (m) 



V = total volume of water (m') strained during the haul 



V = R • a • p 



4 



