FISH FARMING AND THE CONSTRAINTS 



IN JAPAN 



MASARU FUJIYA' 



INTRODUCTION 



Geographically and historically, utilization of 

 marine products, which has been quite significant to 

 the Japanese people and fisheries, is one of the most 

 important industries of the Nation. 



Before the World War II, Japan expanded her 

 fishing area and Japanese fishermen worked all over 

 the world to obtain their foods. The catch was 

 mainly consumed as the protein source for nutrition 

 of the people, and the expansion of production was 

 most important. This situation continued until about 

 a decade ago. 



During recent years the situation has changed re- 

 markably. The Japanese people have demanded 

 greater variety of fishery products of high quality 

 with improvement of their living standard. However, 

 high-quality species occur along the coast of our 

 homeland, and these stocks had decreased because 

 of overfishing and/or water pollution. Under these 

 circumstances, fish farming has become necessary. 



ESSENCE AND SIGNIFICANCE OF 

 FISH FARMING 



In 1962, the Seto Inland Sea Farming Fisheries 

 Association was established, and by 1966 five opera- 

 tion centers were completed and began operation. 

 At present, the tasks of tlsh farming are expanding as 

 scheduled, but some problems remain. Through 

 cooperative research, biologists and fish farming 

 specialists are searching for solutions to these prob- 

 lems in order to advance the operations. Fish farm- 

 ing is somewhat different from ordinary aquaculture. 

 The differences are explained briefly and some con- 

 straints are discussed in this paper. 



When the Seto fish farming operation was started, 

 it was planned to release the larvae following the 



procedures used with salmon and trout. At that time 

 the Inland Sea was regarded as a fish culture pond, 

 and early stages of larvae were released directly 

 from the operation centers without any care because 

 no effective technique had been developed for rear- 

 ing marine fish through their larval stages in captiv- 

 ity. 



Subsequently, it became apparent that more effec- 

 tive utilization of artificially produced larvae was 

 require!^, and some new techniques were developed 

 for larval culture and for acclimation to natural wa- 

 ters. Also, procedures were developed for maintain- 

 ing a brood stock in captivity for earlier production 

 of seedlings and production of more healthy seed- 

 lings. As a new idea, some civil engineering techni- 

 ques were proposed to rehabilitate growing and re- 

 leasing grounds. 



Thus, the present farming fisheries are really 

 equivalent to agriculture in water areas. Artificially 

 produced seedlings are held or planted in shallow 

 coastal regions, and these seedlings utilize natural 

 productivity of these waters for their growth. Recap- 

 ture or harvest occurs within a certain period (Fig. 1) 

 when the products are ready for market. 



SMdIing 



Accltmalion 



Reformation 

 of 

 Growing Growing Areas 



or 

 Rearing 



Recapture 



or 

 Harvest 



Utilization 



of 



Natural Productivity 



' Nansei Regional Fisheries Research l,ahorator\'. Maruishi. 

 Ohno-cho. Saeki-gun. Horoshima-ken. Japan. 



Figure I, — Fundamental conception of Ush tarming. 



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