CH. TX] 



THE PRODUCTIVITY OF THE SEA 



181 



underestimated. The reader must therefore regard this yield 

 of 17 '6 kilogrammes per hectare as only something to start out 

 from in our investigation. When compared with other reliable 

 estimates of the productivity of a sea area it appears very small. 



The North- Western fishing grounds. The North Sea is 

 only one fishing area, and it may interest the reader if I give here 

 the total (minimally estimated) value of the fisheries of the North 

 European nations^. The figures for the year 1904 are : — 



Quantity and value of Jish landed from the fishing grounds 



of North Euroi^e. 



That is, about \\ millions of tons of edible fishes worth about 

 14 millions of pounds were taken in the year 1904 from the fishing 

 grounds of Northern Europe. 



Productivity of an inshore fishing area. Generally 

 speaking one would expect a greater return from the fisheries of a 

 part of the sea lying near the land than from an open sea region. 

 This is because the greater bulk of the fish taken from the North 

 Sea are caught by means of trawl nets, lines and drift nets, while 

 in an inshore fishing area not only are these methods employed 

 but there is also a great amount of fishing by smaller boats 

 for shrimps and prawns, and also a considerable amount of stake 



^ See Bull. Stat. The quantities do not include shellfish landed. The money 

 values do. 



