Diving behaviour of hawaiian skipjack tuna

Abstract

The principal commercial fishery in Hawaii is for oceanic skipjack, Katsuwonus pelamis (Linnaeus), a surface-schooling tuna 40-90 cm in length which is captured exclusively by day using pole-and-line with live-bait as chum. In an attempt to increase the catch per unit of effort, the Honolulu Biological Laboratory (HBL), U.S. Bureau of Commercial Fisheries, has begun studies of skipjack behaviour. Major aspects of this subject have been investigated from an underwater observation chamber mounted on the research vessel “Charles H. Gilbert”. This blister-like structure, which has been described by STRASBURG and YUEN (1960), is located two metres below the surface in the fishing area at the ship’s stern. From this vantage point it is possible to study skipjack behaviour during fishing and at other times. © 1961, Oxford University Press. All rights reserved.