ZOOPLANKTON ABUNDANCE IN THE CENTRAL PACIFIC 



139 



130° 



o 



100 200 300 400 500 600 



DRY WEIGHT OF SAMPLE IN MILLIGRAMS 



Figtjbe 10.— Statinn positions and zooplankton abundance (as dry weight of sample in milligrams) found on the last 



cruise of the Carnegie in 1929 (data from Graham 19411. 



The sample ranking second in dry weight came 

 from 5°30' N. latitude and the third-ranking sam- 

 ple from 2° S. latitude These results, while based 

 on a different method of analysis, are in general 

 agreement with our own observations. 



The Japanese have carried on extensive plank- 

 ton investigations in waters adjacent to the Palau 

 Islands and in the area between the Palaus and 

 New Guinea. Results from the studies of 

 Haneda (1942) and Tokioka (1942) are illus- 

 trated in figure 11. Although these data are 

 rather limited in scope, the samples of Tokioka 



show quite definitely the influence of enrichment 

 near the Equator. 



These surveys and the work of the ('<inu<j't< 

 are the only north-south plankton studies that 

 we are aware of in the equatorial Pacific, other 

 than our own. Unfortunately, the absolute values 

 obtained in them cannot be compared with our 

 results, but the generally similar variations with 

 latitude are of interest. 



While crossing the Pacific from Panama to the 

 Indo-Pacific region, the Dana expedition made 

 plankton tows at frequent intervals. Jesperson 



