Determining Optimal Release Habitat for Black Rockfish, Sebastes schlegelii : Examining Growth Rate, Feeding Condition, and Return Rate
2013; Taylor & Francis; Volume: 21; Issue: 3-4 Linguagem: Inglês
10.1080/10641262.2013.837364
ISSN1547-6553
AutoresByung Sun Chin, Masahiro Nakagawa, Tsutomu Noda, Toshihiro Wada, Yoh Yamashita,
Tópico(s)Coral and Marine Ecosystems Studies
ResumoThe effects of release habitat on the effectiveness of stocking were evaluated in Miyako Bay, Iwate, Japan. Hatchery-reared black rockfish juveniles were released at four different stations characterized by different habitat conditions from 2002–2007, and a survey was conducted of landed fish at Miyako Fish Market. Growth rate and feeding condition of wild and released juveniles sampled from two known wild nursery areas (Stn. 1 and Stn. 2) were also examined to elucidate the conditions that form optimal habitat. Comparisons of growth and feeding condition of juveniles between Stn. 1 and Stn. 2 indicated that Stn. 1, with its brackish waters, seagrass beds, abundant mysids, and large gammarids, supported better growth and survival of released fish, which in turn led to a higher market return rate. The highest market return rate was estimated as 8.3% (for 45-mm total length juveniles released at Stn. 1 in 2007), corresponding to a maximum economic return rate (value of recaptured fish divided by hatchery and release costs) of 1.32.
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