Scientists have identified two stocks of South American pilchard in the waters around Japan: the Pacific Ocean stock and the Tsushima Warm Current stock. The stock designations are based on spawning times and areas, as observed from research surveys conducted around Japan. We have not found evidence of stock structure research involving comparisons with samples from outside of Japan. The Pacific stock spawns November to June from Shikoku to the Kanto region, while the Tsushima stock spawns January to June from around Nagasaki to Toyama prefecture (Fisheries Research and Education Agency of Japan 2017). Although they are assessed separately, the stocks are essentially managed together, with a single TAC set for the two stocks combined. Management responsibilities and actions are largely conducted at the national level, although fishing licenses, especially for smaller purse seine vessels, may be issued at the prefectural level.

This stock may be transboundary, but since 1994, foreign vessels have not harvested this stock within Japan’s EEZ (Yukami et al. 2017). Russian vessels targeted pilchard from 1974 to 1993 before the fishery ceased in 1994 (Zhigalin and Belayev 1999). Korean fisheries harvest modest quantities of pilchard from the Tsushima Warm Current stock but not the Japanese Pacific stock (National Institute of Fisheries Science, Korea n.d.). There is very little information on harvests by China and Taiwan, although pilchard, potentially from the Tsushima Warm Current stock, is a bycatch species in the Yellow Sea.