MARINE FISH CULTURE IN JAPAN 



JOHN B. GLUDE 



INTRODUCTION 



The concept of rearing fishes in floating net cages 

 in sheltered bays or in fish ponds supplied with sea- 

 water has been applied in Japan to several coastal 

 species of high value, and commercial ventures are 

 well established. In 1967 the production of cultivated 

 marine fishes in Japan amounted to 27,103 tons in 

 gross weight worth over $24 million and consisted of 

 98.6% yellowtails, 0.25% puffers or globefish, and 

 1.2% other marine fishes (Harada, 1970). Production 

 of yellowtail has increased remarkably in recent 

 years, as shown by the following table: 



Yield of yellowtail culture 

 iFiirukawa. 1970) 



Year 



Tons 



Production of puffers or globefish by aquaculture 

 has decreased year by year because of the shortage 

 of seed fish, and by 1968 was only 43 tons 

 (Furukawa, 1970). 



A number of species of marine or anadromous 

 fish are being cultivated in seawater in Japan on 

 an experimental or commercial basis, as listed in the 

 following table: 



Species oj fish cultivate tl in seawater in Japan 



Seriota qiiinqueraJiata 

 Seriola purpurescens 

 Loiiiiirostrnin delicalissimus 

 Fui;u nihripes ruhripes 

 Chnsophiys iPai-nisl major 



yellowtail 



amberjack 



striped jack 



puffer (globefish) 



red sea bream (red porgyi 



A canthopagrus schleglii ' 

 Sparus sarha 

 Oplegnathus fasciatus 

 Oplegnathus punctatus 

 Parolichthys olivaceus 

 Sehaslicus marmoralus 

 Oncorhynchus keta 

 Salmo gairdneri irrideiis 

 Sulvetinus phniiis 



black sea bream (black porgy) 



silver sea bream 



Japanese parrotfish 



spotted parrotfish 



bastard halibut 



scorpionfish 



chum salmon 



rainbow trout 



steel head 



' Deputv Regional Director. Northwest Region, National 

 Marine Fisheries Service. NO.\.A. Seattle. W.A 98109. 



' Also listed as Mylio macroccphalus. 



The short time available for the present survey in 

 Japan prevented a complete survey of the status of 

 aquaculture of each of the species listed above, and 

 the following summary is based on brief visits to 

 select locations and several published articles listed 

 below. 



YELLOWTAIL CULTURE 



Culture of the yellowtail, Seriola quinqueradiata, 

 is the most successful marine fish farming venture in 

 Japan, and production from farming now exceeds 

 landings from fishing of wild stocks. Yellowtail cul- 

 ture is conducted by individuals, companies, or 

 fishermen's associations in floating net cages and in 

 fish ponds which are made by partitioning sheltered 

 places from the sea with nets or earthen dams. The 

 great expansion during recent years is because of the 

 increase in the number of floating net cages, since 

 the number of locations suitable for ponds is limited. 



Although spawning, fertilization, hatching, and 

 raising to seedling size have been achieved experi- 

 mentally for yellowtail, methods have not been de- 

 veloped to the stage that seedlings can be produced 

 in commercial quantities for the industry (Harada, 

 1970). Instead, young fish 5-15 cm in length are 

 caught 5-15 miles offshore during April and May. 

 Young yellowtail collect under floating patches of 

 seaweed, and the fishermen simply encircle a mass 

 of seaweed and catch the small fish which are placed 

 in small floating net enclosures. To conserve the nat- 

 ural resources, the Japanese Government has lim- 

 ited the number of young yellowtail which may be 



115 



