126 DISCOVERY REPORTS 



question as to how they got there. Since clearly they could not have been produced in situ and it is 

 unlikely as mentioned above that they could have entered as surface-borne influxes from the east (the 

 Nauplii and Metanauplii in any case being essentially deep living forms), it appears probable that they 

 represent isolated stragglers from a larger population that perhaps had its origin on the continental 

 slope! to the north or east, stragglers that got carried into the shallow water, originally perhaps as 

 eggs, by the warm deep current as it came up against the shelf on which, after a short and weak 

 penetration, it presently died away. The occasional transference of eggs or larvae from the oceanic 

 water to the more southerly reaches of the shelf may well be more effective in the south-eastern part 

 of the Ross Sea than elsewhere, for as the bottom contours in Fig. 13 show it is there, between 170° and 

 180° W, and in about 75° S, that the deep oceanic water, and with it presumably the warm deep 

 layer (although we have no hydrological observations to show it), extends much farther south than it 

 does for instance in the north-west in the neighbourhood of Cape Adare. 



It is interesting to record that when C. A. Larsen originally began hunting the whales in these high 

 latitudes in December 1923 they were wild and difficult to approach, Villiers (1925) remarking that 

 they ' did not come into the Ross Sea in any numbers until after the New Year, and when they did 

 come they found their food very scarce, and so were restless and hard to catch '. It seems, therefore, 

 that these shy whales were either hungry or else resentful of the intrusion of the catchers and new to 

 the experience of the hunt. It is more likely in fact they were hungry, for whales are well known to 

 be more approachable when feeding than when not, Gunther (1949), to quote a particularly reliable 

 observer, noting repeatedly while whale-marking at South Georgia, that when engrossed in a meal 

 they would show neither concern for the approaching vessel nor for the din of the marking guns. He 

 describes the ' supreme indifference ' with which they would accept the marking and the presence of 

 the marking vessel, adding that they 'blew leisurely, sometimes swimming towards us, beneath us 

 and by our side ', apparently preoccupied he says with the question of their meal. Bennett (1931), too, 

 remarks on their lack of shyness when feeding adding, moreover, that it is ' usual for whales to be 

 stupidly "tame" when first a district is exploited'. In similar terms Andrews (1916) refers to the 

 feeding of Balaenoptera borealis, mentioning one occasion when he watched a sei pursuing a school 

 of sardines on the surface, its high dorsal fin exposed and so absorbed in its meal that it ' allowed the 

 ship to approach at once and was killed without difficulty '. 



Larsen, it may be observed, began hunting well out in the middle part of the Ross Sea shelf, about 1 50 

 miles north of the Barrier face. He began, therefore, in a locality where E. siiperba has not been recorded 

 and where in fact the majority of Villiers's restless (or hungry) whales seem to have been seen. Later, when 

 'Sir James Clark Ross', Larsen's factory, moved to Discovery Inlet, well-fed whales, principally blue 

 but with some fin, began to be taken close to the sheltered mothership and there can be little doubt that 

 both species must have been feeding on the swarms of E. crystaUorophias that occur in such profusion 

 along the ice cliffs there. From a photograph by Kohl (1926), of Crustacea captured in Discovery Inlet, 

 showing ' rechts die Gattung Euphausia die die Hauptnahrung der Blauwale darstellt ', it seems clear 

 enough in fact that they were. 



THE OLDER STAGES 

 Economic and ecological importance 

 Euphausia superba, the staple food of the large southern baleen whales, stands perhaps alone among 

 plankton animals in the economy and ecology of the sea. Writing of the South Georgia whaling grounds 

 Hardy and Gunther ( 1 93 5 , p • 208) say, ' Numerically this species is by far the most important member of 

 1 At the single slope station we made in this locality (p. 93, Table 14, Station 1662) five Second NaupHi and ten Meta- 

 nauplii were taken in the 1000-750 m. net, the sounding being 1180 m. 



