This paper reviews historical trends of the catches of the
major commercial species (albacore, bigeye, bluefin, skipjack and yellowfin) of
tunas. The total world catch of these species has increased during the last 50
years (from 0.4 to 3.9 million tonnes), but the pattern of increase has varied
among species, oceans and fishing gears. The causes of those variations are
analysed in this paper. In the world catch, the Pacific Ocean has been
predominant throughout. In recent years catches from the Indian Ocean have
exceeded those from the Atlantic. Skipjack and yellowfin catches have shown a
rapid increase.
Bigeye catches have also shown a constant increase, but at a
lower level. The catches of albacore, bluefin and southern bluefin tunas have
been stable or have decreased in recent years. The baitboat fishery took the
greatest proportion of the total catches during the
1950s. However, the catch
of the purse-seine fishery became significant in the late 1950s and dominant by
1990. Longline catches started picking up in the late 1950s, increased until the
1990s and thereafter declined.