72 DISCOVERY REPORTS 



is scarce simply because the locality is not a very active part of the East Wind-Weddell surface stream 

 in which the krill are otherwise so abundant. Beset in the heart of this vortex in the winter of 1915 

 the 'Endurance' expedition does in fact seem to have found a great scarcity of planktonic life. 

 Shackleton (19 19) writes: 



By the middle of September we were running short of fresh meat for the dogs. The seals and penguins seemed to 

 have abandoned our neighbourhood altogether. Nearly five months had passed since we killed a seal, and penguins 

 had been seen seldom. Clark, who was using his trawl as often as possible, reported that there was a marked absence 

 of plankton^ in the sea, and we assumed that the seals and penguins had gone in search of their accustomed food. 



Clark (191 9) himself, who used his townet almost daily throughout the drift of the 'Endurance', 

 remarks on the scarcity of surface life deep in the heart of the Weddell Sea, adding that the ' lower 

 water strata, down to about 100 fathoms, were only a little more productive, and Euphausiae were 

 taken in the hauls — though sparingly '. 



Table 3. The catches of E. superba deep inside the Weddell Sea ice-field in January ig32 



For most of the year I think conditions in the inaccessible core of the Weddell Sea will probably 

 prove to be much the same as Nansen (1928) found deep in the Arctic basin. He writes: 



Misled by the abundance of vegetable as well as animal plankton they have found in the North Polar Sea near the 

 outskirts of its ice masses, some travellers have assumed that similarly there is much plankton in the water in the 

 interior parts of that sea. This is, however, a mistake. The North Polar Sea, covere4 in its interior by an almost 

 continuous layer of thick ice, is extremely poor in plant as well as animal life. The sunlight is absorbed by the ice, and 

 hardly any of those rays necessary for plant life are able to penetrate the thick floes and into the cold water beneath 

 them. Extremely little plant life can therefore be developed in this sea — there is only just a little, chiefly in the water 

 lanes between the floes in the short summer; and without plant life there can be no animal life. 



The heart of the Arctic basin, he continues, may therefore be considered as 'a desert in the ocean', 

 adding that throughout the drift of the ' Fram ' the fauna encountered ' was so extremely poor in 

 number of specimens that our townets might hang out /or several days- and, although we might drift 

 along at a good speed, there was extremely little in them when they were hauled up '. He notes, 

 however, that in view of the absence or extreme scarcity of the phytoplankton in this area the supply 

 of nutrients, already high as in other parts of the polar sea, will build up enormously and so eventually 

 contribute vastly to the immense wealth of plant and animal life on the marginal parts of the ice-field. 



1 Except for ' plankton ' the italics are mine. 



^ The italics are again mine and I have used them to accentuate the extreme poverty of the plankton this great explorer 

 must have encountered. Compare, for instance, these immensely long periods of towing with the situation in certain ice-free 

 parts of the Antarctic where in a matter of seconds (p. 152) over 100,000 krill may be captured. 



