238 SCIENCE IN AFRICA 



expense of putting down plants for large-scale production would 

 be too heavy. It is worth noting, however, that at least one tribe 

 in Nigeria manufacture and store powdered fish for their own use 

 (see p. 247) and that a trade in fish-meal for native food already 

 exists in French Guinea, where the natives have taken to the new 

 food rapidly. 



The development of fisheries presents special economic problems 

 in territories where the provision for marketing of surplus stock is 

 regarded as a primary necessity, since the competition offish with 

 meat as an article of diet might hamper this policy. 



From the scientific point of view development depends on know- 

 ledge of the fish themselves, both from the taxonomic and eco- 

 logical aspects. The stocks of exploitable fish depend on the 

 food supplies available for them, which in general consist of other 

 animals, whether small fish, members of more lowly orders of the 

 animal kingdom, such as shell-fish, or the enormous quantity of 

 minute floating forms of both animals and plants, known collec- 

 tively as the plankton. These in turn depend on chemical and 

 physical conditions or what may be termed the productive capacity 

 of any water region. Knowledge on all of these subjects is neces- 

 sary for the scientific exploitation of fisheries. A detailed discussion 

 of all these questions is clearly far outside the scope of this chapter, 

 but a few notes on some recent work in Africa are given in the 

 following pages. 



ORGANIZATION AND RESULTS 



BRITISH 



In South Africa the Division of Fisheries under Dr. C. von 

 Bonde, of the Department of Commerce and Industries of the 

 Union Government, conducts a fisheries survey of the whole coast 

 of the Union down to the three hundred fathom line, employing 

 a modern steam research vessel, the R.S. Africana, which is used 

 also for part of each year in hydrographic survey for the correction 

 of charts. Dr. von Bonde is also fisheries adviser to the Cape Pro- 

 vincial Administration. In Natal there is a separate Provincial 

 Fisheries Department and a Fisheries Board. 



Prior to the establishment of the present division of fisheries, 



