Abstract
About 187,000 juvenile hatchery-reared black rockfish Sebastes schlegelii were marked and released in Miyako Bay of Iwate Prefecture each summer during 1999-2001. The total lengths and fished sites of all recaptured S. schlegelii at the Miyako fish market were surveyed through 2005. Among all recaptured S. schlegelii, 1-, 2-, and 3-year-old fish respectively accounted for 88.5%, 10.0%, and 1.5%. Additionally, 91.8% of the 1-year-old recaptured fish were landed during August-December. The average total lengths were 18.0-21.3 cm in August and 21.1-24.8 cm in December of each year. Furthermore, the released fish were recaptured mainly by set nets in the innermost area of the bay during August, although the number of fish recaptured by set nets increased in central and mouth areas from September. These results suggest that 5-10 cm S. schlegelii juveniles released into Miyako Bay stay within the innermost nursery area for a year. Subsequently, they start to migrate from the shallow area to the deep bay mouth area around August the following year.
