DISCOVERY REPORTS 141 



ITINERARIES 



Survey i (march) 

 On the afternoon of the 1 March 1950, the 'William Scoresby' proceeded southward from Lobito 

 Bay towards the outer end of the first line of stations (WS 964, see Fig. 1). This course involved some 

 two days steaming, and it was not until early on the morning of 3 March that the first indications of 

 the Benguela current were met with. In 16 13' S., n° 31' E. the distance thermograph revealed a 

 sudden decrease of sea temperature from 27 C. at 02.45 hr. to 20-5° C. at 03.45 hr - At the same time 

 the echo-soundings showed a sudden increase in depth from 1 10 m. to 439 m. followed by a return to 

 the shallower 1 10-m. level. During the day the temperature rose again, but not to its initial (tropical) 

 level. Evidently the ship had crossed one of the most northerly patches of the cold upwelled water so 

 characteristic of the Benguela system. This may possibly have been associated with the indentation 

 of the continental shelf indicated by the soundings. 



The projected position of the first station was reached just after noon on the 4th, and during the 

 rest of that day six stations were completed, at intervals of some 18 sea-miles, as we worked eastwards 

 in towards the land. The weather was moderately favourable at the first station ( WS 964) and improved 

 as land was approached. Station WS 970, marking the inshore end of the 'Mowe Point' line was 

 completed at 01.27 hr. on the 5th, and the course was continued south-westwards working the five 

 stations of the northern intermediate line (WS 971-5) throughout that day. The wind and sea 

 increased as we proceeded offshore, but fortunately moderated again on the morning of the 6th when 

 we reached the first full station position, WS 976 in 22 50' S. 1 1° 38' E., the outermost station of the 

 'Walvis Bay Line'. This and the following day were spent in completing stations WS 976-9, and on 

 the morning of the 8th, after stations WS 980 and 981, the ship went into Walvis Bay. Here some 

 arrears of chemical analyses were dealt with and some useful information on local fishery matters was 

 gleaned from some of the residents. 



Leaving Walvis Bay on 9 March, the ship passed through large areas of discoloured water, mainly 

 of an olivaceous colour, with small patches of a deeper brown or reddish colour. Surface samples 

 were examined, showing immense numbers of diatoms with but few Gymnodinium spp. The more 

 densely coloured patches contained a small dinoflagellate, which subsequent work on preserved 

 material has shown to be Peridinium triquetrum. Seals (apparently fur-seals) were seen playing lazily 

 in the discoloured water. Our course lay south-westwards, and the middle line of bathythermograph 

 stations was completed by 04.38 hr. on the 10th. At 08.05 hr - the first full station of the ' Sylvia Hill ' 

 line was begun in fine weather, and the clear, almost metallic blue colour of the water here formed 

 a sharp contrast to the turbidity of that inshore. The Nansen-Pettersson water-bottle was visible at 

 a depth of 20 m. By the end of the station, however, the water was obviously more opaque, and 

 steaming eastward we again passed through more discoloured patches within the hour, and con- 

 tinued to do so until 17.05 hr. At station WS 986 there was much macroplankton about the ship; 

 many Ctenophores, mainly in a necrotic condition, and colonies of Salps, were taken out with the 

 hand net. Small shoals of fish were seen, but could not be sampled. 



The 'Sylvia Hill' line was completed before dawn on the nth, and proceeding south-westwards 

 again, on the southernmost line of bathythermograph stations, an otter trawl was used at WS 990. 

 The catch contained several large hake, a fair selection of the other common ground-fish of the region, 

 and some good specimens of Stomatopoda. The outer station of the ' Orange river ' line, WS 996, was 

 reached at 15.55 nr - on the J lth anci tne remaining stations of this line were continued in fine weather, 

 being completed by 03.45 hr. on the morning of 14 March. 



Further observations would, of course, have been desirable, but the commitments of the rest of the 



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