Stock fluctuations of the Japanese common squid, <i>Todarodes pacificus</i>, related to recent climate changes

Abstract

SUMMARY: In Todarodes pacificus, recruitment success is most likely dependent on the physical and biological environments of the spawning and nursery grounds. Annual catches of T. pacificus in Japanese and Korean waters have markedly increased since the late 1980s and the recent catch is equal to that of the 1960s. Here re proposed is a possible scenario for the stock increase since the late-1980s based on GIS analysis of changes in the inferred spawning area during 1984-1999. This study suggests that winter-spawning areas in the East China Sea shrank when adult stocks decreased during a cool regime, and that fall and winter spawning areas extended and overlapped in the Sea of Japan and East China Sea when adult stocks increased during a warm regime. We conclude that stock fluctuations in T. pacificus occur with annual changes of winter-spawning areas related to climatic regime shifts.

Contrast in life histories of exploited fishes and ecosystem structures in coastal waters off west Canada and east Korea

“…During cool water regimes (e.g. after the 1977 regime shift) the winter spawning areas of common squid contracted and were restricted to the East China Sea (Sakurai et al 2000;Sakurai et al 2002). Conversely, during warm water regimes (e.g.…”

Stock Identification of Todarodes pacificus in Northwest Pacific

“…추계군과 동계군이 대다수를 차지하며 그 중에서도 동계군의 자원량이 가장 많은 것으로 (Murata, 1989;Kawabata et al, 2006) 알려져 있다. Sakurai et al(2002) (Murata, 1978), Kim(1990) (Kim and Kang, 1998). 부산주변해역에서 채집된 살오징어는 외투장의 크기에 따라 먹이 생물의 조성이 다르고, 계 절에 따라서는 산란기에 관계없이 연중 섭이하였다 (Song et al, 2006).…”

An overview of the Oyashio ecosystem

“…These regimes coincided with variation in common squid catches, particularly the declines in the early 1980s catch, and the increases in the late 1980s. Sakurai et al (2000Sakurai et al ( , 2002 suggested that the winter spawning areas for common squid in the East China Sea shrank when the adult stocks decreased during the cool regime. Fall and winter spawning areas expanded and overlapped in the Sea of Japan and East China Sea when adult stocks increased during the warm regime that occurred after 1989.…”