Summary of the predation surveys for the tuna longline catch in the Indian and Pacific Ocean based on the Japanese investigation cruises (1954, 1958 and 1966-81)

This report is a summary of the predation surveys for the longline caught tuna and billfishes, which were conducted by the Japanese longline survey cruises in 1954, 58, and 1966-82. In addition, we summarised biology, physiology and ecology of predators and also mitigation measures.