254 SCIENCE IN AFRICA 



months. Brine freezing has disadvantages in that certain changes 

 are apparent after thawing (some external colour and bloom 

 are lost, the exposed gills and blood turn brown and the flesh 

 is very slightly impregnated with salt), but it is the most effective 

 method yet known for keeping fish for long periods. Brine freezing 

 involves a series of operations preliminary to cold storage, and a 

 costly plant, which must be close to the fishing-ground. The 

 process has been developed only in recent years, but there are 

 already three factory ships operating from Hull and Grimsby and 

 two land plants in Norway. In time tropical African fish may figure 

 as luxuries on European menus. 



In various parts of Africa ordinary cold storage is used in the 

 transport of fresh fish to markets away from the source of supply, 

 but there are as yet few ice factories outside the Union. Most of 

 the railways, however, run cold storage vans for the quick trans- 

 port of food for European consumption. Nairobi, for instance, 

 receives a daily supply of fresh fish, alternately from Mombasa on 

 the coast and Kisumu on Lake Victoria. To increase such facilities, 

 it would seem that the time has come for the development of cold 

 storage transport by road in many tropical territories. 



In South Africa the Fisheries Division is now embarking on 

 research into the question of refrigeration offish and facilities have 

 been granted for this work at the Low Temperature Research 

 Laboratory of the Department of Agriculture and Forestry. In 

 connection with brine freezing of fish, an interesting experiment 

 has been started recently by the National Trawling and Fishing 

 Company of Capetown. This company has purchased the patent 

 rights for South Africa of the Societe Anonyme de Congelation Indus- 

 trielle du Poisson, and also a trawler fitted out for their process. By 

 means of rapid freezing the fish are preserved as they come out of 

 the sea. 



The general practice of South African fishermen is to remove the 

 head, guts, and blood before placing the fish on ice. This process is 

 satisfactory for most purposes, as the fishing-grounds are located 

 sufficiently close to the various trawler bases and the use of the 

 new method need not necessarily have revolutionary results. The 

 transportation facilities provided by the South African railways 

 and harbours are quite adequate, and even during the warm sum- 



