| Project/Area Number |
15380133
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General fisheries
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| Research Institution | Tokyo University of Marine Science and Technology (2004-2005)
東京水産大学 (2003) |
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Principal Investigator |
KITADA Shuichi Tokyo University of Marine Science and Technology, Professor, 海洋科学部, 教授 (10262338)
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| Co-Investigator(Kenkyū-buntansha) |
KISHINO Hirohisa University of Tokyo, Graduate School of Agriculture and Life Sciences, Professor, 大学院・農学生命科学研究科, 教授 (00141987)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥15,700,000 (Direct Cost: ¥15,700,000)
Fiscal Year 2005: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2004: ¥5,500,000 (Direct Cost: ¥5,500,000)
Fiscal Year 2003: ¥7,600,000 (Direct Cost: ¥7,600,000)
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| Keywords | Hatchery release / Fishery stock enhancement / Genetic population structure / Genetic impacts of hatchery fish / Microsatellite DNA / Mitochondrial DNA / Pacific herring / Japanese Spanish mackerel / 種苗放流効果 / マダイ / ヒラメ / クルマエビ / 連鎖不平衡 / 遺伝的影響 / 統計的推測 / ベイズ型階層モデル / サクラマス |
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| Research Abstract |
The objective of research is to address the question whether hatchery releases can augment depleted fishery resources with simultaneously maintaining genetic diversity based on analyses of real data.
We took 6 geographical samples of Pacific local herring from spawning areas of Funka Bay, Akkeshi Lake, Yudonuma Lake, Obuchinuma Lake, Miyako Bay, and Matsushima Bay. We also took samples of hatchery fish released and recaptured in Akkeshi Lake and Miyako Bay distinguished from otoliths marked by alizalin complexon. A total of 2,055 individuals were genotyped at five microsatellite loci. Thirty individuals for each locality were also genotyped at D loop region of mt DNA. Though all over genetic differentiation was small with FST of 0.017, local populations with Herdy-Weinburg equilibrium were found forming a metapopulation. Genetic diversity of these populations was high even in stocking areas with small inbreeding coefficients. No allelic difference was found between wild and hatchery released herring, which was considered because 200 adult fish have been used for juvenile production.
We took 3 samples of Japanese Spanish mackerel from the major spawning areas in the Seto Inland Sea. We developed six microsatellite markers and genotyped 300 wild matured fish and 200 hatchery produced juveniles at 5 loci. Genetic differentiation of the natural population was very small with FST of about zero and genetic homogeneity was found in the inland sea with high genetic diversity. On the contrary, the allele frequencies of hatchery fish were found significantly different from those of wild fish, which was resulted in the small number of adult fish (less than 10 individuals) used for artificial fertilization. The mixing rate of hatchery fish released in 2002 was estimated 30.8%. Such high contribution of hatchery fish could impact on the natural population. Our results suggest the need for a cautious approach to stock enhancement programs.
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