A new fish cultivating system powered by a wave energy pump with high efficiency has been developed The basic concept of the system is that the cultivated fish are forced to swim in a sea water tank, so that the quality of their meat is improved by the swimming exercise, so called "Jogging effect". The circulating power of the water stream is supplied by a reciprocating wave-energy pump utilizing natural energy in the sea. At first, the effect of speed and period of swimming on fish body muscle, fat and low temperature preservation characteristics of the cultivated fish were examined to investigate the fish meat Improvement by the exercise. Consequently, it was clearly shown that the fish meat Improvement was remarkable at a swimming speed of 2 5 BL/s, where BL Indicates the body length of a fish. Furthermore, a double-acting reciprocating wave-energy pump was proposed, and the pump characteristics were compared with prototypes, single-acting reciprocating pumps. It was clarified that the double-acting reciprocating wave-energy pump had to be operated with the optimum reciprocating mass, and the efficiency in such a condition was two times higher than the conventional single-acting reciprocating pumps.
The marine product Industry has been hanging low at present because of the restriction of fishery catch and fishing ground In the world. It is urgently required to Improve it to the higher grade by engineering technique and convert to a new Industrial field. The concentration of oxygen dissolved In the sea water reaches the limit on which the fish can live. Morimura (1988) reported that the death of plenty of fish has been caused even by a little change of environmental condition. The contamination In the sea area of a fish farm extended extraordinarily by too much feeding and Industrial pollution of rivers etc.