However, even in a good ground, a project of 

 setting stones or a concrete cover could not be an 

 object of investment from a private enterprise. In 

 Japan, the privilege to harvest seaweeds is reserved 

 for Fishermen's Cooperative Association, who in 

 return is responsible to manage and protect this 

 resource by means of propagating seaweeds and 

 enlarging their substrate. This association has 

 worked on substrate enlargement by stone setting 

 v\ith government aid of 100 million yen per year, an 

 amount too small to improve their total production. 



Other attempts to improve the production from 

 natural beds are found to be not so effective. Elimi- 

 nation of injurious weeds may sometimes improve 

 production in 1 to 2 yr. Also, trials to recover from 

 decreased production in "Isoyake"" waters by stone 

 setting proved to be ineffective. 



On the seaweed grounds, the fauna and tlora have 

 interrelations with each other depending on en- 

 vironmental conditions. Due to the difficulties in 

 changing the environment with a limited budget, the 

 way to increase production or recover from produc- 

 tion declines is to change the succession 

 mechanisms of flora and fauna. 



For instance, in waters where seaweed population 

 has decreased by some accident, starved abalones, 

 top shells, and other gastropods may eat up and 

 consume the young seaweed buds, decreasing the 

 flora recovery. Therefore, to protect these buds, it is 

 necessary to put a large amount of transplanted sea- 

 weeds sufficient enough to feed gastropods and 

 other grazers, preventing the ingestion of buds 

 needed for the vegetation to recover. 



Problems in Seaweed Cultivation 



In cultivation, seaweeds grow on a net, a rope, era 

 raft set or floating at or near the surface of the sea. 

 This means the cultivation is done free from the 

 bottom conditions, on which natural growth of sea- 

 weeds largely depends. The cultivation can be done 

 anywhere on any species, if techniques and water 

 conditions make it profitable. The problems are: 



I ) Whether demand of consumers and tech- 



niques make the cultivation of a seaweed to be 

 profitable or not. 



2) How many water areas can be made into 

 profitable grounds. 



When these terms are met, the amount of production 

 can increase enormously, as it has in the cultivation 

 of Porpliyra. Monostroma, and UnJtirici. and that of 

 Luiniinaiia will follow them in the near future. This is 

 in contrast to the difficulties in increasing production 

 from natural beds, being limited by bottom condi- 

 tions. 



However, the cultivation ofGelitliiiin. Gnu iliirici. 

 Irichu'd. and Chondnis has yet not developed, be- 

 cause it is not profitable. This stems from the fact 

 that these crops are too small or that their cultivation 

 requires too much labor. Here an epochal improve- 

 ment in techniques is expected in making their culti- 

 vation practical. 



In the already industrialized cultivation of 

 Forpliyni and so on, the problems are: 



1 ) How to save labor in its cultivation and make 

 it more comfortable. Mechanization of the work is 

 being done. However, it will result in a reorganiza- 

 tion of the management, from fishermen's private 

 ones to their cooperative operation. 



2) How to change water areas of rough waves 

 into profitable grounds: that is to say, how to 

 improve the culture apparatus to make it more 

 resistant to waves and how to reduce wave action 

 by some engineering techniques. 



3) How to protect cultivated plants from dis- 

 eases, which cause large fluctuations in yearly 

 production. 



4) Hou to improve the quality of products, 

 especially in Porpliyra. to meet better the con- 

 sumers' demands. An effective fertilizing tech- 

 nique is expected to develop. 



5) Breeding is expected to be useful to answer 

 some of these problems. Looking for more favor- 

 able species abroad will be of consequence in the 

 breeding. 



16 



