原著論文
密度指数による本州日本海におけるハタハタ2系群の分布境界域の推定
キーワード:
Arctoscopus japonicus,
density index,
Korea,
migration,
principal component analysis,
sandfish,
Sea of Japan,
stock
2004 年 68 巻 1 号 p. 27-35
詳細
2004 年 68 巻 1 号 p. 27-35
It has been known that there are two main spawning grounds of sandfish Arctoscopus japonicus in the Sea of Japan off Honshu, Japan and the Korea Peninsula: one located off the coast of Akita Prefecture, Honshu, Japan, and the other located on the east coast of Korea. This paper investigated the distribution of these two stocks originating from the two spawning grounds using catches, density indices in 13 areas in the Sea of Japan based on paper per unit effort (CPUE) data and length frequency distributions of female in the offing of Akita Prefecture. The results were as follows: (1) in the offing of Akita Prefecture, monthly CPUE showed two peaks in April and October and very low values in summer; (2) the density indices showed that fish were concentrated near the spawning grounds in October to December; (3) in the offing of Akita Prefecture, the length frequency distributions indicated that 1-year old fish recruited from March to April; and (4) principal component analysis for the annual fluctuation in the density indices in each area indicated that the stock originating in Akita was distributed from the east coast of Korea to the offing of Noto.
