MID-PACIFIC OCEANOGRAPHY III 



Introduction 



This is the third in a series of reports on oceanographic 

 data collected by the Pacific Oceanic Fishery Investigations of the 

 Fish and Wildlife Service„ The first (Cromwell 1951) presented the 

 oceanographic data from Hugh M c Smith cruise 2, the second (Cromwell 

 1954), the data from Hugh M Smith cruises 5 and 8, and this report 

 will be concerned with Hugh M c Smith cruise ll e The apparently 

 missing numbers in the series of cruises by the Smith have been as = 

 signed to oceanographic cruises in the waters adjacent to the Hawaiian 

 Islands or to fishery research cruises and will be the subject of other 

 reports. 



These reports, descriptive in nature, are being issued in 

 order that the oceanographic data may;, as quickly as is feasible, be 

 made available to the other POFI investigations and to other organiza- 

 tions interested in the equatorial mid-Pacific area. It is anticipated 

 that, once the series is complete and the data from all the cruises can 

 be studied together, a series of more comprehensive, analytical re- 

 ports will follow 



The objectives of the equatorial oceanographic cruises 

 have been to describe, in as great detail as possible, the major 

 currents and the distribution of physical and chemical properties 

 of the waters of the mid- Pacific, to determine the spatial and tem- 

 poral variations in these phenomena, and finally to provide physical 

 and chemical oceanographic data to which can be related the distri- 

 bution and abundance of marine organisms, especially tuna, near the 

 Equator c 



Description of Vessel, Equip ment, and Procedures 



The vessel, equipment, and procedures were described 

 in some detail by Cromwell (1951, pp c 1-3),, The only significant 

 change, which we will describe below, is in the procedure for draw- 

 ing the salinity curves and constructing the cross sections as modi- 

 fied from Montgomery (1954). 



Some Res ults of Hugh M„ Smith Cruise 11 



Quoting from the cruise plan, the primary mission was 

 "By means of (1) longline, (2) hydrogr aphic, and (31l plankton stations, 



