22 



Oceanography 



For some years the oceanographic research program of 

 the Biological Laboratory has been concerned with two long- 

 term study projects: summarizing and analyzing oceanographic 

 data from the entire Pacific and investigating the effect of the 

 Hawaiian Islands on circulation patterns near the islands and 

 on circulation systems and water properties of the North 

 Pacific. These projects will be continued in the future. Both 

 are designed to contribute to a comprehensive description and 

 analysis of the Pacific Ocean's physical features and dynamic 

 processes. Such studies of static physical characteristics, of 

 changing oceanographic weather, and of oceanographic climate 

 are fundamental to the progress of the science of oceanography 



DEPTH (M 



and essential to understanding the ecology of the wide-ranging 

 tuna. 



Studies include a summary and analysis of all oceanographic 

 station data of the Pacific obtained from the National Oceano- 

 graphic Data Center; these data are being analyzed in several 

 ways with the principal objective of determining seasonal 

 changes in water properties and currents at various levels 

 within the sea. 



Studies of the characteristics of water layers of a given 

 density (isopycnic surfaces) have been helpful in analyzing 

 seasonal changes in water properties and currents. Figure 25 

 presents an analysis of seasonal changes for water of a given 

 density. It shows the winter and summer values of depth, 

 temperature, salinity, and dissolved oxygen in a water layer 



Ot= 24.40 

 FEBRUART 



0(^24.40 



JULY-ADGDST 



Figure 25. --Summer and winter values of depth, temperature, salinity, and dissolved 

 oxygen content of the water layer of density 1 . 024A grams per cubic centimeter. 



