Literature 



(1) Pettersson, H. : "A Swedish Deep-Sea Expedition." Proc. R. Society, B. 



Vol. 134, p. 399, 1947. 



(2) KuLLENBERG, B. I "The Piston Core Sampler." Svenska hvdr. biol. Ko»i' : s 



Skrifter, Bd. 1 H 2, 1947. 



(3) Weibull, W. : " The Thickness of Ocean Sediments Measured by a Refle.xion 



Method." ]\Iedd. Oceanogr. Inst. Goteborg, 12, 1947. 



(4) Pettersson, H. : " The Swedish Expedition to the \^'estern ^Mediterrean, 



April-Mav 1946." Btill. Inst. Oceanographiqiie Monaco, n : o 919, Oct. 25, 



1947. 

 a.o. : " Three Sediment Cores from the Tyrrhenian Sea." Medd. 



Ocecm. Ibst. Goteborg, 15, 1948, 

 (5) " Manganese Nodules and the Chronology of the Ocean Floor." Medd. 



Oceanogr. Inst. Goteborg, 6, 1943. 

 (6) Phleger, Fred. B., jun. : " Foraminifera of a Submarine Core from the 



Caribbean Sea." Medd. Oceanogr. Inst., Goteborg, 16, 1948. 



REPORT OF WORK CARRIED OUT SINCE 1939 IN THE JAVA 

 SEA BY THE LABORATORY FOR INVESTIGATION OF THE . 



SEA, BATAVIA 



Bv J. D. F. Hardenberg, Batavia 



The work done by the Laboratory for Investigation of the Sea at 

 Batavia came to a complete standstill during the Japanese occupation, 

 and has even now not yet reached this pre-war standard due to the lack 

 of equipment and personnel. 



Much of the instruments for ocean ographic work have been lost or 

 irreparably damaged, and we still have no vessel at out disposal to do 

 work at sea, though just now I am trying to raise the funds to get two 

 ships which, when they have arrived, will survey the whole Indo- 

 Australian Archipelago, which for practical, matters will be divided 

 into a western and an eastern half. 



In the first place salinities will be measured and charted during the 

 different monsoons, in order to get in the course of years a more or less 

 accurate survey of the currents between the islands. This, of course, 

 is already roughly known and can be found in an^^ sailing direction, 

 but experience has shown us that details are very imperfectly known 

 among the many channels, and these details have proven to influence 

 the occurrence or nonoccurrence of different fish of economic value. 



In the second place, the problem of the nutrient salts (phosphates, 

 nitrates, silicates), will be taken in hand. Special attention will be paid 

 to the, if any, eventual existing limiting factors for plankton development 

 in tropical seas. S.o far as our experience goes abundance of diatoms is 

 only found in water masses with a relatively high phosphate content. 

 Thus far never a peak in the diatom population was ascertained when 

 the phosphate content was low as can be the case in temperate waters. 



It seems possible, therefore, that there is a limiting factor (or Hmiting 

 factors) which determine the plankton growth as a whole, which means 

 also that the problem of the productivity of the tropical seas and the 

 problem of the nutrient salt cycle will have to be attacked from another 

 point of view than in colder waters. Next to the ciuestion of the 

 distribution of the salinities and nutrient salts the distribution of the fish 

 win be studied in close co-operation with the results of the fornier 

 investigations. 



190 . 



