798 EIGHTH PACIFIC SCIENCE CONGRESS 



The results, given in Tables I and II, show that 



1) The surface waters from Sagami Bay and Suruga Bay are richer 

 in copper and zinc in comparison with those from the "Kuroshio" area, 

 a fact indicating that the former are still affected by land drainage to 

 any measurable extent. 



2) The vertical distribution, given in Table II, shows that this 

 contamination is limited to the surface and that the contents of the 

 elements decrease in layers below. 



3) Their contents, once decreased, rise up again from 200 m. or 

 thereabout downwards. At the present stage of study it is difficult to 

 decide what is the main factor determining the rise-up observed. How- 

 ever, at least it may be said that here setting free of these elements 

 from dead organisms by decomposition in the course of falling down, 

 contributes to the enrichment in the deeper waters, which is usually 

 the case with other nutrient salts such as phosphate. 



Unfortunately in the February cruise in 1953, the sampling from 

 the "Kuroshio" area could not be clone because of unfavourable condi- 

 tions of the sea. The author is now planning, for the next step of 

 study, an examination of samples from such an area as well as from 

 other bays. Also the study will be extended to far deeper layers than 

 ever examined and further to the seasonal variation of the elements. 

 Efforts are also being made to improve the sampler by which the dura- 

 bility of acrylic resin coating is expected to increase. 



Deepest thanks are due to Professor K. Sugawara for his guidance 

 and to Dr. K. Suda, Director of Hydrographic Office, Maritime Safety 

 Agency, and Professor M. Uda, the Tokyo University of Fisheries, by 

 whose courtesy the author took advantage of participating in the sur- 

 veying cruises. Also a sincerest condolence must be expressed to the 

 late experts and crewmen of No. 5 Kaiyo-maru who missed, with the 

 ship, the voyage for the exploration of Myojin Reef, which appeared 

 last September because of undersea eruption, in recollecting the warmest 

 help offered by them during my stay on board. 



TABLE I 

 Copper and Zinc in the Surface Waters from the "Kuroshio" Area 



Location Date Cu ng/] Zn ixg/\ 



St. 2, 34° 06' N, 138° 09' E May 1, 1951 0.5 1.5 



St. 3, 33° 40' N, 138° 11' E May 2, 1951 O.G 1.3 



St. 4, 33° 16.5' N, 138° 13.5' E May 2, 1951 0.7 — 



