Can long‐term variation in catch of Japanese spiny lobster Panulirus japonicus be explained by larval supply through the Kuroshio Current?

Abstract

Long‐term annual variation in the catch index (CI) of Japanese spiny lobster Panulirus japonicus was examined in relation to the Kuroshio Current index (KCI). We identified two clusters (A, B) of the regions (prefectures) located east (A) and west (B) of Shionomisaki at the southern tip of Kii Peninsula, Japan. There was a significant positive relationship between the KCI at year t and the CI at year t+2 (2 years later) for cluster A. This relationship suggests annual variation in P. japonicus catch may be determined by the variation in puerulus supply through the Kuroshio Current. Relationships between the CI of these two clusters varied depending on 3 periods, which corresponded to 3 regime shifts: years before 1976, from 1977 to 1988, and after 1989. Significant negative relationships were detected between the CI of clusters A and B from 1975 to 2001, whereas a positive but non‐significant relationship was found from 1965 to 1974. Annual variation in the CI of each cluster did not have a significant relationship with the presence/absence of the large‐meander path of the Kuroshio Current.