OBJECTS OF THE INVESTIGATIONS 145 



nature of the food. In whales most of these facts are less easily ascertained than in 

 other mammals and the information already available was very deficient. By special 

 anatomical investigation it is, however, possible to obtain results which will throw much 

 light on such questions, and the Committee consequently decided to build a laboratory 

 at South Georgia. This laboratory, which is known as the Marine Biological Station, 

 is erected on King Edward Point in Cumberland Bay, close to the whaling station at 

 Grytviken. Work has been in progress since January 1925, and it is hoped that the first 

 series of results will shortly be published. A description of the building will be found 

 on p. 223. 



During the southern winter whales are for the most part absent from South Georgia, 

 and at Grytviken it is thus not possible to follow by anatomical investigation the full 

 cycle of reproductive change throughout the year. The Committee considered it most 

 important that complete observations of this kind should be made, and mainly on this 

 account they arranged for the transference of the shore staff to South Africa during 

 the winter of 1926. Thanks to the kindness of Messrs Irvin and Johnson they were 

 accommodated at the whaling station in Saldanha Bay. 



But work on shore, no matter how intensively it is undertaken, can only give solutions 

 to some of the problems which are involved. It requires to be supplemented by observa- 

 tions at sea, and the principal reason for such research is the necessity for a thorough 

 study of the environment of southern whales. Experience has shown that the hydro- 

 logical and planktonic methods employed by the International Council for the Explora- 

 tion of the Sea have been productive of valuable results in the north-east Atlantic and 

 it could not be doubted that equally good results would follow their application in the 

 south. Whaling, like most fisheries, fluctuates greatly from season to season, and the 

 causes of these .fluctuations are to be sought in changes in the environment. The food 

 of southern rorquals is now known to consist exclusively, or almost exclusively, of large 

 Euphausian crustaceans, which themselves feed mainly on diatoms. On analogy with 

 conditions ascertained in the north, the seasonal abundance of the Euphausians on the 

 whaling grounds of the Dependencies will be preceded by a period of great reproductive 

 activity in the phytoplankton. The phytoplankton in its turn is dependent on the 

 physical and chemical constitution of the water, and it is to hydrological, and ultimately 

 perhaps to meteorological conditions, that the fluctuations in the whaling industry are 

 to be ascribed. 



So much could be inferred from the scientific work which had been done in the north, 

 but much special investigation in the south was needed before theory and fact were 

 brought into accord. The life history of the Euphausian which forms the main food of 

 whales was unknown and no information existed on its relations with the other con- 

 stituents of the plankton. Knowledge of the southern phytoplankton was limited almost 

 entirely to the specific identification of the various species, and data on the water move- 

 ments and general hydrology of the south were wholly deficient. 



It was accordingly decided to equip a vessel for oceanographic research in southern 

 waters. The 'Discovery', originally built for the National Antarctic Expedition, 



