Samples for analysis of deuterium were 

 taken at stations as indicated on figure 1. These 

 samples were forwarded to Dr. Irving Friedman, 

 U. S. Geological Survey, Washington, D. C, 

 for analyses. 



On both vessels the standard weather 

 observations were recorded at the position of 

 each BT. These data, along with the other data 

 normally recorded with each BT lowering, are 

 listed in tables 1 and 2. In addition, the Smith 

 recorded weather observations at 0000, 0600, 

 1200, and 1800 GOT daily; the Gilbert at 0600 

 and 1800 GCT. These data, recorded on USWB 

 Form 1210-F, are listed in tables 3 and 4. 



During the cruise, a total of 460 BT 

 observations were made from the Smith ; lower - 

 ings were made at about 15 minutes before 

 arrival at an oceanographic station, at messen- 

 ger time or just after station, and at 3-hour 

 intervals between stations. The Gilbert made 

 a total of 243 lowerings with one every 3 hours 

 during the runs between Honolulu and the Mar- 

 quesas and return, three during each longline 

 station, and four each day in the Marquesan 

 area while scouting and live-bait fishing. On the 

 Gilbert, chloride and phosphate samples were 

 obtained once each day, in conjunction with aBT 

 lowering, on all runs except between 5°N. and 

 5°S. latitude, where they were taken with every 

 other BT, and the resulting data are included in 

 table 2. The recording thermograph was oper- 

 ated continuously on both vessels while underway. 



The Gilbert made Secchi disc lowerings 

 and water color determinations ( Forel scale) 

 each day at noon whenever weather conditions 

 were suitable (table 5). 



Carbon Fixation 



The rate of primary productivity was 

 measured in a total of 106 samples by using the 

 carbon isotope (Cl4) niethod as developed by 

 Steemann Nielsen (1952) and modified by Doty 

 (King et al. , 1957). The samples were collected 

 and processed aboard the Smith by M. Angot, 

 collaborator from the Ins ti tut Francais 

 D'Oceanie, New Caledonia. The program was 

 carried out in cooperation with the University of 

 Hawaii. 



Zooplankton 



South of 12°N. latitude, the Smith made 

 a total of 40 two -net, oblique tows employing on 

 each haul a 1 -meter net of 656 Nitex (apertures 

 0.66 mm. in width) and a 45-cm. net of 308 

 Nitex (apertures 0.31 mm. in width) , the two 



nets being towed simultaneously from a single 

 wire. These tows were made each night start- 

 ing at 2100 hours. The 40 -minute, oblique, 

 1 -meter net tow, to a depth of about 200 meters, 

 was essentially the standard POFI tow as des- 

 cribed by King and Demond (1953). The 30- 

 minute , oblique, 45-cm. net tow to a depth of 

 about 150 nneters was adopted as standard for 

 all participants in EQUAPAC at a conference 

 held in Honolulu during February, 1956. 



In addition to the above night-time tows, 

 a total of 23 oblique 1 -meter net hauls to 200- 

 225 meters were made from the Smith during 

 daylight hours. 



The depths at which the nets sampled 

 were estimated by utilizing wire angle and 

 length of wire out. These data were recorded 

 every 2 minutes and the depth determined 

 therefrom on the assumption that the towing 

 wire described a straight line (King and Demond 

 1953). 



During daylight hours while patrolling 

 the longline (see fig. 2 for positions of longline 

 stations), the Gilbert made a total of 19 half- 

 hour, single -net surface tows using a 1 -meter 

 net of 656 Nitex. Fifteen half -hour tows were 

 made each night with two nets fishing simul- 

 taneously. In addition, in order to examine 

 statistically the variability related to the haul- 

 ing method, one double -net, half -hour tow and 

 one single-net, 1 -hour tow were made as time 

 permitted. The primary purpose of this 

 sampling on the Gilbert was to evaluate these 

 different methods for collecting tuna larvae. As 

 these tows also provided a measure of the 

 standing crop of zooplankton in the surface 

 waters, the resulting data are included in table 

 19 of this report. 



Midwater Trawl 



The Smith made 35 1 -hour hauls from 

 the surface to approximately 200 meters using 

 the modified, 10-foot Isaacs-Kidd trawl 

 (Devereaux and Winsett 1953). These hauls 



were made at 2000-2100 hours each evening, 

 just before the plankton tows. A description of 

 the net and hauling method is given by King, et 

 al. (1957). 



Bait Surveys and Fishing 



Bait surveys and tuna fishing, the latter 

 by longline, trolling and live bait, were con- 

 ducted primarily from the Gilbert . The Smith 

 performed trolling, incidental to the primary 

 mission with two lines during daylight hours 



