Table 1. — Change in annual amount of seaweed production. 

 [Wet basis: 1,000 tons.] 



Seaweed Harvested 

 from 



1936-40 



1941-45 



1946-50 



1951-55 



1956-60 



l%l-65 



1966-70 



Consumed 

 in 



Nori Cultivation 27 



tPorphyra) Natural bed 



Wakame Cultivation 



(Undaria) Natural bed 37 



Monostroma Cultivation 



Laminuria Natural bed 305 



Gelidiiim Natural bed 12 



Gracilaria Natural bed 



Iridaea and 



Chondnis Natural bed 



Cloiopellis Natural bed 5 



Ecklonia and 



Eisenia Natural bed 



33 



31 



132 



36 



139 



18 

 48 



148 



17 

 12 



45 



51 

 12 



142 



15 

 12 



61 

 7 



4 



57 



14 



144 



13 



169 



7 



66 

 57 



15 



167 



18 



118 



Food 

 Food 



Food 

 Food 



Food 



Food. 

 A part, 

 alginate 

 material 



Agar 

 material 



Agar 

 material 



Mostly- 

 plastering 



Starch 

 for silk 

 clothes 



A part, 

 alginate 

 material 



The nori harvest increased only gradually, 

 amounting to 1 billion sheets — a sheet is a paperlike 



product of nori, of about 20 x 20 cm in size and about 

 3 g in weight — just before World War 11. 



Advances in the culture techniques were also 

 poor. Old collectors (twigs from trees of oak, cherry, 

 etc.) were replaced by bamboo twigs, promising 

 more harvest than the old ones. Modern net collec- 

 tors were found more effective to increase the har- 

 vest, but they were adopted only in limited localities 

 because of the higher cost than the old collectors. 



It should he mentioned here, that the nori cultiva- 

 tion in Korea had a rapid growth 10 years prior to 

 World War it by introducing new techniques which 

 produced about the same amount of nori as in 

 Japan. 



After World War 11, nori cultivation in Japan 

 made rapid progress. The amount of the harvest 



doubled in 1945, became four times in 1955, and is 

 now six times that of the prewar level. 

 Social economic reasons for this abrupt rise are: 



1) Increase in the demand by consumers. The 

 food rationing system during and after World War 

 11 supplied nori to all of the people in Japan, mak- 

 ing many new consumers. The increase of con- 

 sumers and the halt of the import of nori from 

 Korea brought about a severe shortage of nori and 

 the rise of market price. 



2) Innovation of fisheries systems after the War. 

 Nori cultivators organized themselves in cooper- 

 ative unions, which shut out the capital control of 

 dealers and established a cooperative selling sys- 

 tem that raised the rate of net income from about 

 30% in the prewar times to an income of 60-70%. 



Rise of the market price of nori and increase 



