THE AGE OF FEMALE BLUE WHALES 

 AND THE EFFECT OF WHALING ON 



THE STOCK 



By Alec H. Laurie, m.a. 

 (Text-figs. 1-14) 



INTRODUCTION 



Investigations into the life history of Southern Blue and Fin whales were begun 

 in South Georgia as far back as 1913, when Barrett-Hamilton laid the foundations of 

 the present methods of study. Members of the staff of the Discovery Investigations 

 continued the work on a relatively large scale at Grytviken, South Georgia, from 1925 to 

 1931. Results of this work appear in Discovery Reports (1929, 1930, 1934, and 1935). 

 The Report by Wheeler (1934) is important, because by the time it was published 

 knowledge of Fin whales had advanced to the point at which tentative conclusions 

 regarding the stock of whales and the effect of whaling thereon could be drawn. 



Before proceeding to biological considerations it will be as well to outline the industrial 

 background of pelagic whaling. The following resume is intended to elucidate the condi- 

 tions under which modern whaling is carried on and the material of this paper was 

 gathered in order that the limitations of the data may be understood. For fuller in- 

 formation the reader is referred to works on whaling quoted in the bibliography. 



I would record with gratitude the help and encouragement given me by Mr M. A. C. 

 Hinton, F.R.S., with whom I have had many useful discussions. Dr A. S. Parkes, 

 F.R.S., of the Medical Research Council, kindly assisted in the histological examination 

 of ovaries. Thanks are also due to Mr T. Edser, of the Ministry of Agriculture and 

 Fisheries, who has willingly spared the time to discuss population problems. I am 

 grateful also to Dr Stanley Kemp, F.R.S., Dr N. A. Mackintosh, and Mr J. O. Borley 

 for much useful criticism and advice. Contributions of material for this work are 

 acknowledged in the appropriate place. 



modern pelagic whaling. The first whaling activities in the Falkland Dependencies 

 were carried out from a land station. Here the boilers and other accessories for cooking 

 the blubber, meat, and bones were located strategically around the flensing plan at the 

 water's edge where the whales were hauled up and dismembered. A typical land station 

 has been described by Mackintosh and Wheeler (1929, p. 262). 



The earliest floating factories to be used in the Southern whaling grounds went to the 

 South Shetlands in the first decade of this century. They were in essence floating oil 

 refineries and cargo ships combined. Flensing and dismemberment of the carcasses 



