from 175° E. to 171° E. longitude; 

 northward from 56° N. to 60° N. lati- 

 tude; and southward from 49° N. to 

 47° N. latitude. 



Water samples 



The spacing of the Nansen bottles 

 was similar to the previous year ex- 

 cept that the bottle at 25 meters, which 

 was usually located at the top of the 

 thermocline, was replaced by bottles 

 at 20 and 30 nieters. This was done 

 to avoid the difficulties in obtaining 

 interpolated values by machine methods 

 at depths where sharp gradients of 

 properties are encountered. 



Equipment 



The portable hydrographic winches, 

 usually installed on board the vessels, 

 were no longer serviceable. The 

 winches used this year were pernna- 

 nent installations aboard eachvessel. 



Space was not available aboard the 

 small vessels for chemical analyses 

 that would provide innmediate environ- 

 mental conditions. Therefore an ex- 

 perimental temperature- conductivity 

 cell was towed astern of the Pioneer 

 to provide a continuous record of 

 surface temperature and salinity. The 

 cell, designed and constructed by the 

 Fisheries Instrumentation Laboratory, 

 Seattle, Washington, requires further 

 modifications and improvements be- 

 fore it can be considered operational. 



Plankton 



The vertical plankton haul to 300 

 meters was replaced by a 30-meter 

 vertical haul to permit abetter evalua- 

 tion of the surface plankton. The 150- 

 meter depth trawl, using the modified 

 Isaac s-Kidd trawl, which proved un- 

 rewarding, was discontinued, and only 

 a night surface trawl was made to 

 determine the food organisms present 

 at the surface in the vicinity of the gill 

 nets. 



Drift bottles 



This year, hooks were attached to 

 the drift bottles to permit capture in 



gill nets by the high seas fishing fleets; 

 however, none of our bottles have been 

 reported recovered in this manner. 



LABORATORY PROCEDURE 



Chemistry 



Chemical analyses were performed 

 in Adak, Alaska, and Seattle, Washing- 

 ton, Through the cooperation of the 

 U. S. Navy, a temporary laboratory 

 was established in Adak. All oxygen 

 samples except those collected on the 

 return voyage were analyzed in Adak. 

 Chlorinity samples were returned to 

 Seattle for analysis. Chlorinity and 

 dissolved oxygen samples were deter- 

 mined by titration, utilizing the Knud- 

 sen and Winkler methods, respectively. 



Data presentation 



The following headings are used in 

 presenting the observed data: 



Position- -Latitude and longitude 

 determined by loran readings at all 

 positions and supplemented by celestial 

 sights in some positions. 



Time- -The date and hour (GCT) 

 at which the messenger was released. 

 The second hour indicates the time of 

 the second cast or, in case of more 

 than two casts, the time of the final 

 cast. 



Weather observations--Observed 

 readings and coded values as presented 

 in U. S. Navy Hydrographic Office Pub- 

 lication 606-C (1956). 



Barometer- -Readings from ship- 

 board barometer coded in millibars. 



Wet and dry bulbs- -Readings from 

 hygrometer. 



Physical, chennical data- -All 

 values were plotted versus depth, and 

 checked by T-S curves before being 

 punched on IBM cards. 



DEPTH--Depth in meters obtained 

 by smoothed L-Z curve, 

 or in some instances 

 from the wire angle. 



