Biodiversity as Observed from Catch Size Differences between Longtail Tuna and Other Commercial Fish Species Caught with Set Net off Futaoi Island (Western Sea of Japan)

摘要

Differences in catch sizes by fishing season between longtail tuna and other commercial fish species caught with set net off Futaoi Island (western Sea of Japan) are examined. In this study, longtail tuna, barracuda, and greater amberjack have similarfishing seasons. Among the feed species of longtail tuna (horse mackerel, sardine, and mackerel),horse mackerel was always caught during the longtail tuna fishing season. The fishing season of longtail tuna starts after the yellowtail amberjack catch; and, the yellowtail amberjack fishing period finishes after the longtail tuna catch.