430 DISCOVERY REPORTS 



in the Atlantic sector, be replenished by incursions of breeders or potential breeders from lower latitudes. 

 Thus while on the Atlantic or Weddell side we can postulate a southward dispersal of the very early 

 larvae as a mechanism of distributional control, we cannot see the same mechanism at work all round 

 Antarctica.^ In the absence of recruitment from the north, that is, from the West Wind drift, the 

 continued existence of the high latitude west-moving population throughout a vast stretch of the East 

 Wind zone, reaching from Graham Land west about to the neighbourhood of Enderby Land, 

 becomes in fact in the present state of our knowledge a very difficult thing to explain. Obviously, 

 however, if there is no recruitment from the north there must be continual recruitment from the east, 

 and this would imply a continuous circulation that could only be maintained it seems if there were 

 transference of East Wind water from the Weddell side to the Pacific side via the narrow channel of 

 the Bransfield Strait. In his study of the hydrology of this enclosed basin Clowes (1934) finds no 

 such transference, although he does find a strong surface movement of East Wind water from the 

 Weddell side which spreads across the north-eastern end of the strait and down the coast of Trinity 

 Peninsula, a movement that seems to be associated (p. 311, Fig. 75) with the drifting of young 

 Calyptopes swarms for some little distance westwards into the channel. Although, however, no through 

 east to west movement has been established it seems possible that it might sometimes happen, Clowes 

 (1934), in a note on the ice conditions of this region, observing that during seasons of prevailing 

 northerly and north-easterly winds the pack-ice will move out of the channel in a south-westerly 

 direction, sometimes, as in March 1924, travelling to the south-west right into the middle of de Ger- 

 lache Strait. 



The Oceanographic Atlas of the Polar Seas published by the U.S.N. Hydrographic Office in 1957 

 and Muromtsev (1958, Fig. 80) both show a supposed rotary movement at the surface in the Bellings- 

 hausen Sea immediately to the west of Alexander I Island, a movement involving northward transport 

 of East Wind water into the West Wind zone near Peter I Island and its supposed return, bending 

 southwards and south-westwards, along the Charcot Island-Alexander I Island coast. Such a move- 

 ment, if real, 2 could, it might be supposed, produce a small-scale circulation of euphausians involving 

 the local replenishment of the East Wind drift with either surface-borne larvae (p. 311, Fig. 75 and 

 p. 315, Fig. 78) or older stages returned from the West Wind zone. It is just conceivable, too, 

 that from such an enclosed or locally circulating community the recruitment of the west-going 

 population in the East Wind drift could have its westerly beginnings, without postulating any move- 

 ment of East Wind water from the Weddell to the Pacific side by way of the Bransfield Strait. 



On the Atlantic or Weddell side of Antarctica Meyer (1923, end chart) shows a cyclonic movement 

 at the surface between 20° and 50° W with its centre in the heart of the Weddell Sea in about 70° S, 

 35° W, a rotary movement involving the return of part of the east-going Weddell stream to the East 

 Wind drift. Farther east he shows another movement, again involving the return of Weddell water 

 to the East Wind zone, with its centre north of Enderby Land. Hansen (1934, Pis. iv-vii) and the, 

 folder maps in the end-pocket of Atlas over Antarktis og Sydishavet published by Hvalfangernes 

 Assuranceforening (1936) show similar movements, evidently taken directly from Meyer. Kruger 

 (^939> Fig- 68) reproduces Meyer's original map. Liineburg (1940, Fig. 10) shows a supposed current ! 

 moving counter to the Weddell drift ('Weddellgegenstrom') flowing from about 25° E to about 

 15° W between latitudes 62° and 63° S. Hentschel (1941, Beilage) follows Meyer, Ritscher (1942, 

 Fig- 36), however, showing only his western vortex. Schott (1942, PI. xxii) also shows Meyer's western 1 



' Except in the sense that the deep larvae in the East Wind drift itself (p. 123) are constantly, it seems, being carried by | 

 the warm layer deeper (in the latitudinal sense) into this coastwise current. 



- The track of the drifting ' Belgica' (de Gerlache, 1943), beset in the pack of the Bellingshausen Sea, does provide some 

 evidence of a rotary movement at the surface here, and according to Rouch (1922) a southward movement probably does exist. 



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