UNEVENNESS OF OCEANIC PLANKTON 



527 



100-1 



90- 



80- 



70 



< 60- 



LJ 

 CO 



50 



40 



CL 



S30 



20 



approximate values, also for Globigerina and Radiolaria, are blocked in as histograms in 

 Fig. 12. Record 23 was interrupted ; after recording for only three sections it was taken 

 inboard at 2030 owing to ice conditions and put out again at 0800 the following morning. 

 Phytoplankton was dense on the first three sections ; next morning it was almost absent 

 for some 18 miles, when it appeared again in small quantities until towards the end of the 

 record where it increased greatly. Record 24 was also interrupted during the night on 

 account of difficult ice conditions. Phytoplankton was dense throughout the record 



10- 

 0>-4>- 



REC0RD 23 



PHAE0CYSTI5 



RECORD 24 



THALA55IDTHRIX 



FRAG I L ARIA 



I 2 3 



C05CIN0- 

 DI5CU5 



GLOBIGERINA 

 RADIOLARIA 



CHAETOCEROS 



NO C0PEP0DA 

 1 



5 10 15 



RECORDER SECTIONS 



5 10 



RECORDER SECTIONS 



15 



HOUR 



AND 



DATE 



▲ ▲ 



N0V.I3. § § 



OJ D 



NOV. 14. 



o 

 o 



K 



in 



LD 

 O 



NOV. 19. 



o o 



nj o 



O CD 



cvl o 



NOV. 20. Q 

 ru 



Fig. 12. Variations in the quantities of the predominant plankton organisms on Records 23 and 24. Except for Copepoda 

 the relative abundance of organisms is shown by a scale of + signs: +, ++, + + + .... 



except for a few miles at the beginning of the renewed run. Copepoda were absent from 

 record 24 and all but absent from the dense phytoplankton zones at the beginning and 

 end of record 23 ; they were present, however, in fair numbers (see Fig. 12) in the region 

 of poor phytoplankton over the greater part of record 23. To what extent does this dis- 

 tribution support the inverse relationship between zoo- and phytoplankton discussed 

 by the author in the former report (Hardy and Gunther, 1935)? Can the reduced num- 

 ber of Copepoda in the zones of dense phytoplankton be entirely due to the loss of 

 filtration by the silk becoming clogged with the diatoms? To some extent this must 



