The Japanese common squid Todarodes
pacificus catch constitutes approximately 56% of the
total cephalopod catch in Japan, and constitutes the
majority of the Japanese squid catch. The total catch of
T. pacificus in Japan has varied widely, with relatively
low catches (< 200 000 t) until 1950. The lowest catch
was 25 000 t in 1908 and the highest catch was 668000
t in 1968. There was then a gradual decrease that
began in the 1970s, followed by an increase after 1986
(Fig. 1a). The lowest catch since then was in 1998,
when 180749 t were recorded; this was 40% of Japan’s
largest recorded catch, which was made during 1996
(Fig. 1b). It is important to determine whether fluctuations
in the T. pacificus catch are due to overfishing or
to environmental changes or both. Recent research
(Sakurai et al. 2000) has shown that variations in
oceanographic conditions, such as extension of possible
spawning areas, influence both the distribution
and abundance of T. pacificus. Kang et al. (2002)