R. W. Owen has also obtained data on total particu- 

 late carbon for complete profiles at many stations from 

 six cruises, together with light-scattering data from many 

 of the same profiles. A good correlation has been detec- 

 ted between particulate-carbon concentration and the 

 volume-attenuation coefficient of green light. Such cor- 

 relation indicates that organic particles have a higli degree 

 of influence on the inherent particulate properties of 

 these tropical waters. 



Of over 5,600 productivity samples from 800 sta- 

 tions and 14,000 plant pigment measurements from 

 1,200 stations, about 10 percent have been processed and 

 examined. Preliminary analyses of these samples show 

 that the distribution of chlorophyll and seston agrees well 

 with expectation and give evidence of seasonal cycles of 

 clilorophyll and seston. Unexpectedly higli concentra- 



Occurrence of lan'ac in samples from first EASTROPAC 

 survey: shaded are areas of occurrence. 



G. Mattson 



David Starr Joidzn-shipboard autoanalysis of concen- 

 tration's of nutrient chemicals in sea water samples. 



tions of plant pigments were found beyond equatorial 

 waters; they sometimes exceeded equatorial values, de- 

 spite the apparently greater local enrichment by upwell- 

 ing along the equator. 



The continuous in vivo chlorophyll records from 

 the surface water taken during most of the EASTROPAC 

 cruises are very useful for analyzing small scale variations 

 and for locating areas of large changes of pigment con- 

 centrations, such as at oceanic fronts. Diurnal changes 

 of in vivo fluorescence, which occur mainly in equatorial 

 waters, indicate, however, that this measurement is not a 

 particularly good tool for surveys of large areas. 



R.M. Laurs, who is directing the work of processing 

 of zooplankton samples taken on EASTROPAC, reports 

 that it is progressing well. Volume measurements of 

 samples from 1 .0- and 0.5-m. nets have been completed 

 for all collections taken on the first and second survey 

 cruises, and on all monitor cruises, and are well along for 

 the third survey cruise. Computer listings of standardized 

 volumes are now available for the first survey, and the 

 first two monitor cruises, data from other cruises are 

 being punched on computer cards. 



17 



