Figure 3. --Track of the Charles H. Gilbert . 



Entries were made on Oceanographic 

 Log Sheet "B" in conjunction with BT lowerings . 

 These entries were coded according to Hydro- 

 graphic Office Publication 606 -c and are repro- 

 duced in table 1. Included in this table are 

 salinity determinations of surface water samples 

 taken at BT lowerings. 



Standard weather observations were 

 made up to 4times dailyduring Gilbert 43. The 

 observations were coded according to U. S. 

 Weather Bureau Form 1210-Fand are presented 

 in table 3. 



Although no bathythermograph lowerings 

 or standard weather observations were made on 

 board the Cape Falcon, the Government observer 

 made routine observations on the environment 

 which were coded and recorded on Oceanographic 

 Log Sheet "B", These observations are pre- 

 sented in table 2, which also includes salinity 

 determinations of surface water samples taken 



in conjunction with Sonne of the environmental 

 observations . 



Pro ductivity observations 



Water transparency observations using 

 a 30 cm. Secchi disc and water color observa- 

 tions by comparison with the Forel standard 

 were made at local noon daily during Gilbert 43 

 while in the Marquesas area (table 5). 



A study of the rate of carbon dioxide 

 uptake by the C method was made in various 

 localities between Hawaii, the Marquesas, and 

 the Society Islands in collaboration with the 

 Commonwealth Scientific and Industrial Re- 

 search Organization (C.S.I. R. O. ) , Australia 

 and the University of Hawaii. The results of 

 this study will be published elsewhere. 



Surface troUin 



R. 



Varying numbers of lines were trolled 

 from the Gilbert while running to and from the 

 survey areas and while scouting for surface 

 schools. The catches and related data are 

 given in table 6. 



Varying numbers of lines were trolled 

 from the Cape Falcon , while scouting for sur- 

 face schools in the survey areas. The troll 

 catches are presented in table 7. 



Live -bait fishing 



The live -bait pole -and -line fishing 

 techniques used on Gilbert 43 were similar to 

 those of the Hawaiian skipjack fishery (June 

 1951). Marquesan sardines were used as bait. 

 The results of fishing and other related data 

 are presented in table 8. The length -frequency 

 distribution of samples of skipjack, yellowfin, 

 and bigeye caught are given in table 10. 



The fishing techniques of California 

 baitboat fishermen were used aboard the Cape 

 Falcon. A description of the techniques is 

 given by Godsil (1938). Anchovetas obtained at 

 Almejas Bay, Baja California, were used as 

 bait. The results of fishing and other pertinent 

 data are presented in table 9. The length-fre- 

 quency distribution of samples of yellowfin and 

 skipjack caught are given in table 11. 



Baitfish surveys 



Descriptions of procedures used in con- 

 ducting baitfish surveys in the Marquesas have 

 appeared in earlier publications (Wilson and 

 Rinkel 1957, and Wilson, et al. 1958). The 



