rope-curtain type, was popularized, as in Uiuhiria in 

 southern Hokkaido. 



Brown algae (Undaria pinnatifida) 



The distributional range of Undaria in Hokkaido 

 is generally the same as that of abalone. In recent 

 times, the annual production of Undaria in Hok- 

 kaido has been constant at about 10.000 tons in fresh 

 weight. 



Red algae (Porphyra spp., mainly Porphyra yezoensis) 



Hokkaido is still an underdeveloped area for the 

 cultivation of Porphyra because there are many ob- 

 stacles hindering its growth, such as heavy wind- 

 storms along the Japan Sea coast, freezing of sea 

 waters, and floating drift ice in the inlets along the 

 eastern part of the Pacific coast and the Okhotsk 

 coast. However, since 1953. the cultivation oi Por- 

 phyra has increased gradually in Uchiura Bay, Ak- 

 keshi Bay. and the northern part of the Japan Sea 

 coast. In the former two places, the algae are not 

 damaged by the above obstacles, while in the latter 

 place, they are protected by special breakwater 

 fences. 



IMPORTANT PROBLEMS 

 OF THE RESEARCH ACTIVITIES 



As in many agencies, organization, staff, budgets, 

 and facilities are problems affecting research ac- 

 tivities. However, these are omitted from this dis- 

 cussion for want of space. The problems to be solved 

 in future studies are as follows: 



All species being artificially propagated 



1) Identification of food organisms and develop- 

 ing best methods for their mass production. 



2) Determination of an adaptive environmental 

 condition for each species. 



3) Determination of the size and the quality of 



seed to be stocked and places where stocking \\ ill be 

 done. 



4) Explanation of an annexing effect to the natural 

 stocks as an important problem in the future. 



Scallop 



1) Clarification of the major factors causing the 

 decline in populations on both the Japan Sea coast 

 and the northern part of the Okhotsk Sea coast. 



2) Establishment of a large-scale, dependable sys- 

 tem for the mass production of seed (target is 800 

 million individuals). 



Japanese surf clam 



Establishment of a large-scale, dependable system 

 for producing seed both naturally and artificially. 



Abalone and sea urchin 



Establishment of a technique for artificially plant- 

 ing seaweeds and clarification on the ability of 

 abalone and sea urchin to propagate following plant- 

 ing. 



Laminaria 



1) Investigation of methods of growing high qual- 

 ity Laminaria {2-yr old plants). 



2) Improvement of methods forthe forced cultiva- 

 tion of Laminaria (1-yrold plants). 



3) Study how to protect the cultured Laminaria 

 from the noxious bryozoan. Memhranipora ser- 

 rilamella. 



Porphyra 



1) Identification of the new local species and the 

 breeding of Porphyra. 



2) Study the adaptation of each local species to its 

 environmental conditions. 



3) Establishment of a suitable culture technique 

 for each local condition. 



