抄録
Five marine ranches which have acoustic sound for red sea bream have been made in the Oita prefectural
sea area since 1986. The four of them are located in the northern part of the Bungo-suido, Usuki and Tsukumi
bay. In this report, We have tried to simulate future management for them with emphasis on the economic effects,
using twelve types of management factors, in term of seed liberation, size regulation, fishing days and their
combinations.
As a result of this, the net profits for natural and liberated fish in regards to the three types of management
factors were connected mostly with size regulation. The seed liberation factor does not provide enough profit in
itself. To provide economic gains size regulation should be added as a management factor. And, in order to
achieve the manegement aim, a period of five years is necessary after the management system is started.
